Re: review: CHECK FUNCTION statement

Bruce Momjian <bruce@momjian.us>

From: Bruce Momjian <bruce@momjian.us>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: Albe Laurenz <laurenz.albe@wien.gv.at>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2012-08-17T01:08:00Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Add const qualifiers to node inspection functions

What happened to this feature patch?  A TODO?

---------------------------------------------------------------------------

On Tue, Nov 29, 2011 at 08:37:15PM +0100, Pavel Stehule wrote:
> Hello
> 
> updated patch:
> 
> * recheck compilation and initdb
> * working routines moved to pl_exec.c
> * add entry to catalog.sgml about lanchecker field
> * add node's utils
> 
> Regards
> 
> Pavel Stehule
> 
> 2011/11/29 Albe Laurenz <laurenz.albe@wien.gv.at>:
> > Pavel Stehule wrote:
> >> I am sending updated patch, that implements a CHECK FUNCTION and CHECK
> >> TRIGGER statements.
> >>
> >> This patch is significantly redesigned to previous version (PL/pgSQL
> >> part) - it is more readable, more accurate. There are new regress
> >> tests.
> >>
> >> Please, can some English native speaker fix doc and comments?
> >
> >> ToDo:
> >>
> >> CHECK FUNCTION search function according to function signature - it
> >> should be changes for using a actual types - it can be solution for
> >> polymorphic types and useful tool for work with overloaded functions -
> >> when is not clean, that function was executed.
> >>
> >> check function foo(int, int);
> >> NOTICE: checking function foo(variadic anyarray)
> >> ...
> >>
> >> and maybe some support for named parameters
> >> check function foo(name text, surname text);
> >> NOTICE: checking function foo(text, text, text, text)
> >> ...
> >
> > I think that CHECK FUNCTION should work exactly like DROP FUNCTION
> > in these respects.
> >
> > Submission review:
> > ------------------
> >
> > The patch is context diff, applies with some offsets, contains
> > regression tests and documentation.
> >
> > The documentation should be expanded, the doc for CHECK FUNCTION
> > is only a stub. It should describe the procedure and what is checked.
> > That would also make reviewing easier.
> > I think that some documentation should be added to plhandler.sgml.
> > There is a spelling error (statemnt) in the docs.
> >
> > Usability review:
> > -----------------
> >
> > If I understand right, the goal of CHECK FUNCTION is to find errors in
> > the function definition without actually having to execute it.
> > The patch tries to provide this for PL/pgSQL.
> >
> > There hasn't been any discussion on the list, the patch was just posted,
> > so I can't say that we want that. Tom added it to the commitfest page,
> > so there's one important voice against dismissing it right away :^)
> >
> > I don't understand the functional difference between a "validator function"
> > and a "check function" as proposed by this patch. I am probably missing
> > something, but why couldn't these checks be added to function validation
> > when check_function_bodies is set?
> > A new "CHECK FUNCTION" statement could simply call the validator function.
> >
> > I don't see any pg_dump support in this patch, and PL/pgSQL probably doesn't
> > need that, but I think pg_dump support for CREATE LANGUAGE would have to
> > be added for other PLs.
> >
> > I can't test if the functionality is complete because I can't get it to
> > run (see below).
> >
> > Feature test:
> > -------------
> >
> > I can't really test the patch because initdb fails:
> >
> > $ initdb -E UTF8 --locale=de_DE.UTF-8 --lc-messages=en_US.UTF-8 -U postgres /postgres/cvs/dbhome
> > The files belonging to this database system will be owned by user "laurenz".
> > This user must also own the server process.
> >
> > The database cluster will be initialized with locales
> >  COLLATE:  de_DE.UTF-8
> >  CTYPE:    de_DE.UTF-8
> >  MESSAGES: en_US.UTF-8
> >  MONETARY: de_DE.UTF-8
> >  NUMERIC:  de_DE.UTF-8
> >  TIME:     de_DE.UTF-8
> > The default text search configuration will be set to "german".
> >
> > creating directory /postgres/cvs/dbhome ... ok
> > creating subdirectories ... ok
> > selecting default max_connections ... 100
> > selecting default shared_buffers ... 32MB
> > creating configuration files ... ok
> > creating template1 database in /postgres/cvs/dbhome/base/1 ... ok
> > initializing pg_authid ... ok
> > initializing dependencies ... ok
> > creating system views ... ok
> > loading system objects' descriptions ... ok
> > creating collations ... ok
> > creating conversions ... ok
> > creating dictionaries ... ok
> > setting privileges on built-in objects ... ok
> > creating information schema ... ok
> > loading PL/pgSQL server-side language ... FATAL:  could not load library "/postgres/cvs/pg92/lib/plpgsql.so": /postgres/cvs/pg92/lib/plpgsql.so: undefined symbol: plpgsql_delete_function
> > STATEMENT:  CREATE EXTENSION plpgsql;
> >
> > child process exited with exit code 1
> > initdb: removing data directory "/postgres/cvs/dbhome"
> >
> > Coding review:
> > --------------
> >
> > The patch compiles without warnings.
> > The comments in the code should be revised, they are bad English.
> > I can't say if there should be more of them -- I don't know this part of
> > the code well enough to have a well-founded opinion.
> >
> > I don't think there are any portability issues, but I could not test it.
> >
> > There are a lot of small changes to pl/plpgsql/src/pl_exec.c, are they all
> > necessary? For example, why was copy_plpgsql_datum renamed to
> > plpgsql_copy_datum?
> >
> > I'll mark the patch as "Waiting on Author".
> >
> > Yours,
> > Laurenz Albe
> >

> *** ./doc/src/sgml/catalogs.sgml.orig	2011-11-29 19:09:02.000000000 +0100
> --- ./doc/src/sgml/catalogs.sgml	2011-11-29 20:28:00.571246006 +0100
> ***************
> *** 3652,3657 ****
> --- 3652,3668 ----
>        </row>
>   
>        <row>
> +       <entry><structfield>lanchecker</structfield></entry>
> +       <entry><type>oid</type></entry>
> +       <entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
> +       <entry>
> +        This references a language checker function that is responsible
> +        for checking a embedded SQL and can provide detailed checking.
> +        Zero if no checker is provided.
> +       </entry>
> +      </row>
> + 
> +      <row>
>         <entry><structfield>lanacl</structfield></entry>
>         <entry><type>aclitem[]</type></entry>
>         <entry></entry>
> *** ./doc/src/sgml/ref/allfiles.sgml.orig	2011-11-29 19:20:59.468117093 +0100
> --- ./doc/src/sgml/ref/allfiles.sgml	2011-11-29 19:21:24.487804955 +0100
> ***************
> *** 40,45 ****
> --- 40,46 ----
>   <!ENTITY alterView          SYSTEM "alter_view.sgml">
>   <!ENTITY analyze            SYSTEM "analyze.sgml">
>   <!ENTITY begin              SYSTEM "begin.sgml">
> + <!ENTITY checkFunction      SYSTEM "check_function.sgml">
>   <!ENTITY checkpoint         SYSTEM "checkpoint.sgml">
>   <!ENTITY close              SYSTEM "close.sgml">
>   <!ENTITY cluster            SYSTEM "cluster.sgml">
> *** ./doc/src/sgml/ref/create_language.sgml.orig	2011-11-29 19:20:59.470117069 +0100
> --- ./doc/src/sgml/ref/create_language.sgml	2011-11-29 19:21:24.488804943 +0100
> ***************
> *** 23,29 ****
>   <synopsis>
>   CREATE [ OR REPLACE ] [ PROCEDURAL ] LANGUAGE <replaceable class="parameter">name</replaceable>
>   CREATE [ OR REPLACE ] [ TRUSTED ] [ PROCEDURAL ] LANGUAGE <replaceable class="parameter">name</replaceable>
> !     HANDLER <replaceable class="parameter">call_handler</replaceable> [ INLINE <replaceable class="parameter">inline_handler</replaceable> ] [ VALIDATOR <replaceable>valfunction</replaceable> ]
>   </synopsis>
>    </refsynopsisdiv>
>   
> --- 23,29 ----
>   <synopsis>
>   CREATE [ OR REPLACE ] [ PROCEDURAL ] LANGUAGE <replaceable class="parameter">name</replaceable>
>   CREATE [ OR REPLACE ] [ TRUSTED ] [ PROCEDURAL ] LANGUAGE <replaceable class="parameter">name</replaceable>
> !     HANDLER <replaceable class="parameter">call_handler</replaceable> [ INLINE <replaceable class="parameter">inline_handler</replaceable> ] [ VALIDATOR <replaceable>valfunction</replaceable> ] [ CHECK <replaceable>checkfunction</replaceable> ]
>   </synopsis>
>    </refsynopsisdiv>
>   
> ***************
> *** 217,222 ****
> --- 217,236 ----
>         </para>
>        </listitem>
>       </varlistentry>
> + 
> +     <varlistentry>
> +      <term><literal>CHECK</literal> <replaceable class="parameter">checkfunction</replaceable></term>
> + 
> +      <listitem>
> +       <para><replaceable class="parameter">checkfunction</replaceable> is the
> +        name of a previously registered function that will be called
> +        when a new function in the language is created, to check the
> +        function by statemnt <command>CHECK FUNCTION</command> or 
> +        <command>CHECK TRIGGER</command>.
> +       </para>
> +      </listitem>
> +     </varlistentry>
> + 
>      </variablelist>
>   
>     <para>
> *** ./doc/src/sgml/reference.sgml.orig	2011-11-29 19:20:59.471117057 +0100
> --- ./doc/src/sgml/reference.sgml	2011-11-29 19:21:24.492804895 +0100
> ***************
> *** 68,73 ****
> --- 68,74 ----
>      &alterView;
>      &analyze;
>      &begin;
> +    &checkFunction;
>      &checkpoint;
>      &close;
>      &cluster;
> *** ./src/backend/catalog/pg_proc.c.orig	2011-11-29 19:20:59.474117021 +0100
> --- ./src/backend/catalog/pg_proc.c	2011-11-29 19:21:24.494804869 +0100
> ***************
> *** 1101,1103 ****
> --- 1101,1104 ----
>   	*newcursorpos = newcp;
>   	return false;
>   }
> + 
> *** ./src/backend/commands/functioncmds.c.orig	2011-11-29 19:20:59.475117009 +0100
> --- ./src/backend/commands/functioncmds.c	2011-11-29 19:21:24.496804843 +0100
> ***************
> *** 44,53 ****
> --- 44,55 ----
>   #include "catalog/pg_namespace.h"
>   #include "catalog/pg_proc.h"
>   #include "catalog/pg_proc_fn.h"
> + #include "catalog/pg_trigger.h"
>   #include "catalog/pg_type.h"
>   #include "catalog/pg_type_fn.h"
>   #include "commands/defrem.h"
>   #include "commands/proclang.h"
> + #include "commands/trigger.h"
>   #include "miscadmin.h"
>   #include "optimizer/var.h"
>   #include "parser/parse_coerce.h"
> ***************
> *** 60,65 ****
> --- 62,68 ----
>   #include "utils/fmgroids.h"
>   #include "utils/guc.h"
>   #include "utils/lsyscache.h"
> + #include "utils/memutils.h"
>   #include "utils/rel.h"
>   #include "utils/syscache.h"
>   #include "utils/tqual.h"
> ***************
> *** 1009,1014 ****
> --- 1012,1152 ----
>   	}
>   }
>   
> + /*
> +  * CheckFunction
> +  *			call a PL checker function when this function exists.
> +  */
> + void
> + CheckFunction(CheckFunctionStmt *stmt)
> + {
> + 	List	   *functionName = stmt->funcname;
> + 	List	   *argTypes = stmt->args;	/* list of TypeName nodes */
> + 	Oid			funcOid;
> + 
> + 	HeapTuple	tup;
> + 	Form_pg_proc proc;
> + 
> + 	HeapTuple	languageTuple;
> + 	Form_pg_language languageStruct;
> + 	Oid		languageChecker;
> + 	Oid trgOid = InvalidOid;
> + 	Oid	relid = InvalidOid;
> + 
> + 	/* when we should to check trigger, then we should to find a trigger handler */
> + 	if (functionName == NULL)
> + 	{
> + 		HeapTuple	ht_trig;
> + 		Form_pg_trigger trigrec;
> + 		ScanKeyData skey[1];
> + 		Relation	tgrel;
> + 		SysScanDesc tgscan;
> + 		char *fname;
> + 
> + 		relid = RangeVarGetRelid(stmt->relation, ShareLock, false, false);
> + 		trgOid = get_trigger_oid(relid, stmt->trgname, false);
> + 
> + 		/*
> + 		 * Fetch the pg_trigger tuple by the Oid of the trigger
> + 		 */
> + 		tgrel = heap_open(TriggerRelationId, AccessShareLock);
> + 
> + 		ScanKeyInit(&skey[0],
> + 					ObjectIdAttributeNumber,
> + 					BTEqualStrategyNumber, F_OIDEQ,
> + 					ObjectIdGetDatum(trgOid));
> + 
> + 		tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true,
> + 									SnapshotNow, 1, skey);
> + 
> + 		ht_trig = systable_getnext(tgscan);
> + 
> + 		if (!HeapTupleIsValid(ht_trig))
> + 			elog(ERROR, "could not find tuple for trigger %u", trgOid);
> + 
> + 		trigrec = (Form_pg_trigger) GETSTRUCT(ht_trig);
> + 
> + 		/* we need to know trigger function to get PL checker function */
> + 		funcOid = trigrec->tgfoid;
> + 		fname = format_procedure(funcOid);
> + 		/* Clean up */
> + 		systable_endscan(tgscan);
> + 
> + 		elog(NOTICE, "checking function \"%s\"", fname);
> + 		pfree(fname);
> + 
> + 		heap_close(tgrel, AccessShareLock);
> + 	}
> + 	else
> + 	{
> + 		/*
> + 		 * Find the function, 
> + 		 */
> + 		funcOid = LookupFuncNameTypeNames(functionName, argTypes, false);
> + 	}
> + 
> + 	tup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcOid));
> + 	if (!HeapTupleIsValid(tup)) /* should not happen */
> + 		elog(ERROR, "cache lookup failed for function %u", funcOid);
> + 
> + 	proc = (Form_pg_proc) GETSTRUCT(tup);
> + 
> + 	languageTuple = SearchSysCache1(LANGOID, ObjectIdGetDatum(proc->prolang));
> + 	Assert(HeapTupleIsValid(languageTuple));
> + 
> + 	languageStruct = (Form_pg_language) GETSTRUCT(languageTuple);
> + 	languageChecker = languageStruct->lanchecker;
> + 
> + 	/* Check a function body */
> + 	if (OidIsValid(languageChecker))
> + 	{
> + 		ArrayType  *set_items = NULL;
> + 		int			save_nestlevel;
> + 		Datum	datum;
> + 		bool		isnull;
> + 		MemoryContext oldCxt;
> + 		MemoryContext checkCxt;
> + 
> + 		datum = SysCacheGetAttr(PROCOID, tup, Anum_pg_proc_proconfig, &isnull);
> + 
> + 		if (!isnull)
> + 		{
> + 			/* Set per-function configuration parameters */
> + 			set_items = (ArrayType *) DatumGetPointer(datum);
> + 			if (set_items)			/* Need a new GUC nesting level */
> + 			{
> + 				save_nestlevel = NewGUCNestLevel();
> + 				ProcessGUCArray(set_items,
> + 							(superuser() ? PGC_SUSET : PGC_USERSET),
> + 							PGC_S_SESSION,
> + 							GUC_ACTION_SAVE);
> + 			}
> + 			else
> + 				save_nestlevel = 0; /* keep compiler quiet */
> + 		}
> + 
> + 		checkCxt = AllocSetContextCreate(CurrentMemoryContext,
> + 									"Check temporary context",
> + 									ALLOCSET_DEFAULT_MINSIZE,
> + 									ALLOCSET_DEFAULT_INITSIZE,
> + 									ALLOCSET_DEFAULT_MAXSIZE);
> + 
> + 		oldCxt = MemoryContextSwitchTo(checkCxt);
> + 
> + 		OidFunctionCall2(languageChecker, ObjectIdGetDatum(funcOid), 
> + 							    ObjectIdGetDatum(relid));
> + 
> + 		MemoryContextSwitchTo(oldCxt);
> + 
> + 		if (set_items)
> + 			AtEOXact_GUC(true, save_nestlevel);
> + 	}
> + 	else
> + 		elog(WARNING, "language \"%s\" has no defined checker function",
> + 			    NameStr(languageStruct->lanname));
> + 
> + 	ReleaseSysCache(languageTuple);
> + 	ReleaseSysCache(tup);
> + }
>   
>   /*
>    * Rename function
> *** ./src/backend/commands/proclang.c.orig	2011-11-29 19:20:59.477116983 +0100
> --- ./src/backend/commands/proclang.c	2011-11-29 19:21:24.497804830 +0100
> ***************
> *** 46,57 ****
>   	char	   *tmplhandler;	/* name of handler function */
>   	char	   *tmplinline;		/* name of anonymous-block handler, or NULL */
>   	char	   *tmplvalidator;	/* name of validator function, or NULL */
>   	char	   *tmpllibrary;	/* path of shared library */
>   } PLTemplate;
>   
>   static void create_proc_lang(const char *languageName, bool replace,
>   				 Oid languageOwner, Oid handlerOid, Oid inlineOid,
> ! 				 Oid valOid, bool trusted);
>   static PLTemplate *find_language_template(const char *languageName);
>   static void AlterLanguageOwner_internal(HeapTuple tup, Relation rel,
>   							Oid newOwnerId);
> --- 46,58 ----
>   	char	   *tmplhandler;	/* name of handler function */
>   	char	   *tmplinline;		/* name of anonymous-block handler, or NULL */
>   	char	   *tmplvalidator;	/* name of validator function, or NULL */
> + 	char	   *tmplchecker;	/* name of checker function, or NULL */
>   	char	   *tmpllibrary;	/* path of shared library */
>   } PLTemplate;
>   
>   static void create_proc_lang(const char *languageName, bool replace,
>   				 Oid languageOwner, Oid handlerOid, Oid inlineOid,
> ! 				 Oid valOid, Oid checkerOid, bool trusted);
>   static PLTemplate *find_language_template(const char *languageName);
>   static void AlterLanguageOwner_internal(HeapTuple tup, Relation rel,
>   							Oid newOwnerId);
> ***************
> *** 67,75 ****
>   	PLTemplate *pltemplate;
>   	Oid			handlerOid,
>   				inlineOid,
> ! 				valOid;
>   	Oid			funcrettype;
> ! 	Oid			funcargtypes[1];
>   
>   	/*
>   	 * If we have template information for the language, ignore the supplied
> --- 68,77 ----
>   	PLTemplate *pltemplate;
>   	Oid			handlerOid,
>   				inlineOid,
> ! 				valOid,
> ! 				checkerOid;
>   	Oid			funcrettype;
> ! 	Oid			funcargtypes[2];
>   
>   	/*
>   	 * If we have template information for the language, ignore the supplied
> ***************
> *** 219,228 ****
>   		else
>   			valOid = InvalidOid;
>   
>   		/* ok, create it */
>   		create_proc_lang(stmt->plname, stmt->replace, GetUserId(),
>   						 handlerOid, inlineOid,
> ! 						 valOid, pltemplate->tmpltrusted);
>   	}
>   	else
>   	{
> --- 221,269 ----
>   		else
>   			valOid = InvalidOid;
>   
> + 		/*
> + 		 * Likewise for the checker, if required; but we don't care about
> + 		 * its return type.
> + 		 */
> + 		if (pltemplate->tmplchecker)
> + 		{
> + 			funcname = SystemFuncName(pltemplate->tmplchecker);
> + 			funcargtypes[0] = OIDOID;
> + 			funcargtypes[1] = REGCLASSOID;
> + 			checkerOid = LookupFuncName(funcname, 2, funcargtypes, true);
> + 			if (!OidIsValid(checkerOid))
> + 			{
> + 				checkerOid = ProcedureCreate(pltemplate->tmplchecker,
> + 										 PG_CATALOG_NAMESPACE,
> + 										 false, /* replace */
> + 										 false, /* returnsSet */
> + 										 VOIDOID,
> + 										 ClanguageId,
> + 										 F_FMGR_C_VALIDATOR,
> + 										 pltemplate->tmplchecker,
> + 										 pltemplate->tmpllibrary,
> + 										 false, /* isAgg */
> + 										 false, /* isWindowFunc */
> + 										 false, /* security_definer */
> + 										 true,	/* isStrict */
> + 										 PROVOLATILE_VOLATILE,
> + 										 buildoidvector(funcargtypes, 2),
> + 										 PointerGetDatum(NULL),
> + 										 PointerGetDatum(NULL),
> + 										 PointerGetDatum(NULL),
> + 										 NIL,
> + 										 PointerGetDatum(NULL),
> + 										 1,
> + 										 0);
> + 			}
> + 		}
> + 		else
> + 			checkerOid = InvalidOid;
> + 
>   		/* ok, create it */
>   		create_proc_lang(stmt->plname, stmt->replace, GetUserId(),
>   						 handlerOid, inlineOid,
> ! 						 valOid, checkerOid, pltemplate->tmpltrusted);
>   	}
>   	else
>   	{
> ***************
> *** 294,303 ****
>   		else
>   			valOid = InvalidOid;
>   
>   		/* ok, create it */
>   		create_proc_lang(stmt->plname, stmt->replace, GetUserId(),
>   						 handlerOid, inlineOid,
> ! 						 valOid, stmt->pltrusted);
>   	}
>   }
>   
> --- 335,355 ----
>   		else
>   			valOid = InvalidOid;
>   
> + 		/* validate the checker function */
> + 		if (stmt->plchecker)
> + 		{
> + 			funcargtypes[0] = OIDOID;
> + 			funcargtypes[1] = REGCLASSOID;
> + 			checkerOid = LookupFuncName(stmt->plchecker, 2, funcargtypes, false);
> + 			/* return value is ignored, so we don't check the type */
> + 		}
> + 		else
> + 			checkerOid = InvalidOid;
> + 
>   		/* ok, create it */
>   		create_proc_lang(stmt->plname, stmt->replace, GetUserId(),
>   						 handlerOid, inlineOid,
> ! 						 valOid, checkerOid, stmt->pltrusted);
>   	}
>   }
>   
> ***************
> *** 307,313 ****
>   static void
>   create_proc_lang(const char *languageName, bool replace,
>   				 Oid languageOwner, Oid handlerOid, Oid inlineOid,
> ! 				 Oid valOid, bool trusted)
>   {
>   	Relation	rel;
>   	TupleDesc	tupDesc;
> --- 359,365 ----
>   static void
>   create_proc_lang(const char *languageName, bool replace,
>   				 Oid languageOwner, Oid handlerOid, Oid inlineOid,
> ! 				 Oid valOid, Oid checkerOid, bool trusted)
>   {
>   	Relation	rel;
>   	TupleDesc	tupDesc;
> ***************
> *** 337,342 ****
> --- 389,395 ----
>   	values[Anum_pg_language_lanplcallfoid - 1] = ObjectIdGetDatum(handlerOid);
>   	values[Anum_pg_language_laninline - 1] = ObjectIdGetDatum(inlineOid);
>   	values[Anum_pg_language_lanvalidator - 1] = ObjectIdGetDatum(valOid);
> + 	values[Anum_pg_language_lanchecker - 1] = ObjectIdGetDatum(checkerOid);
>   	nulls[Anum_pg_language_lanacl - 1] = true;
>   
>   	/* Check for pre-existing definition */
> ***************
> *** 423,428 ****
> --- 476,490 ----
>   		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
>   	}
>   
> + 	/* dependency on the checker function, if any */
> + 	if (OidIsValid(checkerOid))
> + 	{
> + 		referenced.classId = ProcedureRelationId;
> + 		referenced.objectId = checkerOid;
> + 		referenced.objectSubId = 0;
> + 		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
> + 	}
> + 
>   	/* Post creation hook for new procedural language */
>   	InvokeObjectAccessHook(OAT_POST_CREATE,
>   						   LanguageRelationId, myself.objectId, 0);
> ***************
> *** 478,483 ****
> --- 540,550 ----
>   		if (!isnull)
>   			result->tmplvalidator = TextDatumGetCString(datum);
>   
> + 		datum = heap_getattr(tup, Anum_pg_pltemplate_tmplchecker,
> + 							 RelationGetDescr(rel), &isnull);
> + 		if (!isnull)
> + 			result->tmplchecker = TextDatumGetCString(datum);
> + 
>   		datum = heap_getattr(tup, Anum_pg_pltemplate_tmpllibrary,
>   							 RelationGetDescr(rel), &isnull);
>   		if (!isnull)
> *** ./src/backend/nodes/copyfuncs.c.orig	2011-11-29 19:09:02.000000000 +0100
> --- ./src/backend/nodes/copyfuncs.c	2011-11-29 20:17:01.339172458 +0100
> ***************
> *** 2880,2885 ****
> --- 2880,2898 ----
>   	return newnode;
>   }
>   
> + static CheckFunctionStmt *
> + _copyCheckFunctionStmt(CheckFunctionStmt *from)
> + {
> + 	CheckFunctionStmt *newnode = makeNode(CheckFunctionStmt);
> + 
> + 	COPY_NODE_FIELD(funcname);
> + 	COPY_NODE_FIELD(args);
> + 	COPY_STRING_FIELD(trgname);
> + 	COPY_NODE_FIELD(relation);
> + 
> + 	return newnode;
> + }
> + 
>   static DoStmt *
>   _copyDoStmt(DoStmt *from)
>   {
> ***************
> *** 4165,4170 ****
> --- 4178,4186 ----
>   		case T_AlterFunctionStmt:
>   			retval = _copyAlterFunctionStmt(from);
>   			break;
> + 		case T_CheckFunctionStmt:
> + 			retval = _copyCheckFunctionStmt(from);
> + 			break;
>   		case T_DoStmt:
>   			retval = _copyDoStmt(from);
>   			break;
> *** ./src/backend/nodes/equalfuncs.c.orig	2011-11-29 20:19:55.045587471 +0100
> --- ./src/backend/nodes/equalfuncs.c	2011-11-29 20:19:21.850082357 +0100
> ***************
> *** 1292,1297 ****
> --- 1292,1308 ----
>   }
>   
>   static bool
> + _equalCheckFunctionStmt(CheckFunctionStmt *a, CheckFunctionStmt *b)
> + {
> + 	COMPARE_NODE_FIELD(funcname);
> + 	COMPARE_NODE_FIELD(args);
> + 	COMPARE_STRING_FIELD(trgname);
> + 	COMPARE_NODE_FIELD(relation);
> + 
> + 	return true;
> + }
> + 
> + static bool
>   _equalDoStmt(DoStmt *a, DoStmt *b)
>   {
>   	COMPARE_NODE_FIELD(args);
> ***************
> *** 2708,2713 ****
> --- 2719,2727 ----
>   		case T_AlterFunctionStmt:
>   			retval = _equalAlterFunctionStmt(a, b);
>   			break;
> + 		case T_CheckFunctionStmt:
> + 			retval = _equalCheckFunctionStmt(a, b);
> + 			break;
>   		case T_DoStmt:
>   			retval = _equalDoStmt(a, b);
>   			break;
> *** ./src/backend/parser/gram.y.orig	2011-11-29 19:09:02.876463248 +0100
> --- ./src/backend/parser/gram.y	2011-11-29 19:21:24.502804769 +0100
> ***************
> *** 227,232 ****
> --- 227,233 ----
>   		DeallocateStmt PrepareStmt ExecuteStmt
>   		DropOwnedStmt ReassignOwnedStmt
>   		AlterTSConfigurationStmt AlterTSDictionaryStmt
> + 		CheckFunctionStmt
>   
>   %type <node>	select_no_parens select_with_parens select_clause
>   				simple_select values_clause
> ***************
> *** 276,282 ****
>   
>   %type <list>	func_name handler_name qual_Op qual_all_Op subquery_Op
>   				opt_class opt_inline_handler opt_validator validator_clause
> ! 				opt_collate
>   
>   %type <range>	qualified_name OptConstrFromTable
>   
> --- 277,283 ----
>   
>   %type <list>	func_name handler_name qual_Op qual_all_Op subquery_Op
>   				opt_class opt_inline_handler opt_validator validator_clause
> ! 				opt_collate opt_checker
>   
>   %type <range>	qualified_name OptConstrFromTable
>   
> ***************
> *** 700,705 ****
> --- 701,707 ----
>   			| AlterUserSetStmt
>   			| AlterUserStmt
>   			| AnalyzeStmt
> + 			| CheckFunctionStmt
>   			| CheckPointStmt
>   			| ClosePortalStmt
>   			| ClusterStmt
> ***************
> *** 3174,3184 ****
>   				n->plhandler = NIL;
>   				n->plinline = NIL;
>   				n->plvalidator = NIL;
>   				n->pltrusted = false;
>   				$$ = (Node *)n;
>   			}
>   			| CREATE opt_or_replace opt_trusted opt_procedural LANGUAGE ColId_or_Sconst
> ! 			  HANDLER handler_name opt_inline_handler opt_validator
>   			{
>   				CreatePLangStmt *n = makeNode(CreatePLangStmt);
>   				n->replace = $2;
> --- 3176,3187 ----
>   				n->plhandler = NIL;
>   				n->plinline = NIL;
>   				n->plvalidator = NIL;
> + 				n->plchecker = NIL;
>   				n->pltrusted = false;
>   				$$ = (Node *)n;
>   			}
>   			| CREATE opt_or_replace opt_trusted opt_procedural LANGUAGE ColId_or_Sconst
> ! 			  HANDLER handler_name opt_inline_handler opt_validator opt_checker
>   			{
>   				CreatePLangStmt *n = makeNode(CreatePLangStmt);
>   				n->replace = $2;
> ***************
> *** 3186,3191 ****
> --- 3189,3195 ----
>   				n->plhandler = $8;
>   				n->plinline = $9;
>   				n->plvalidator = $10;
> + 				n->plchecker = $11;
>   				n->pltrusted = $3;
>   				$$ = (Node *)n;
>   			}
> ***************
> *** 3220,3225 ****
> --- 3224,3234 ----
>   			| /*EMPTY*/								{ $$ = NIL; }
>   		;
>   
> + opt_checker:
> + 			CHECK handler_name					{ $$ = $2; }
> + 			| /*EMPTY*/								{ $$ = NIL; }
> + 		;
> + 
>   DropPLangStmt:
>   			DROP opt_procedural LANGUAGE ColId_or_Sconst opt_drop_behavior
>   				{
> ***************
> *** 6250,6255 ****
> --- 6259,6294 ----
>   
>   /*****************************************************************************
>    *
> +  *		CHECK FUNCTION funcname(args)
> +  *		CHECK TRIGGER triggername ON table
> +  *
> +  *
> +  *****************************************************************************/
> + 
> + 
> + CheckFunctionStmt:
> + 			CHECK FUNCTION func_name func_args
> + 				{
> + 					CheckFunctionStmt *n = makeNode(CheckFunctionStmt);
> + 					n->funcname = $3;
> + 					n->args = extractArgTypes($4);
> + 					n->trgname = NULL;
> + 					n->relation = NULL;
> + 					$$ = (Node *) n;
> + 				}
> + 			| CHECK TRIGGER name ON qualified_name
> + 				{
> + 					CheckFunctionStmt *n = makeNode(CheckFunctionStmt);
> + 					n->funcname = NULL;
> + 					n->args = NIL;
> + 					n->trgname = $3;
> + 					n->relation = $5;
> + 					$$ = (Node *) n;
> + 				}
> + 		;
> + 
> + /*****************************************************************************
> +  *
>    *		DO <anonymous code block> [ LANGUAGE language ]
>    *
>    * We use a DefElem list for future extensibility, and to allow flexibility
> *** ./src/backend/tcop/utility.c.orig	2011-11-29 19:20:59.480116945 +0100
> --- ./src/backend/tcop/utility.c	2011-11-29 19:21:24.513804628 +0100
> ***************
> *** 882,887 ****
> --- 882,891 ----
>   			AlterFunction((AlterFunctionStmt *) parsetree);
>   			break;
>   
> + 		case T_CheckFunctionStmt:
> + 			CheckFunction((CheckFunctionStmt *) parsetree);
> + 			break;
> + 
>   		case T_IndexStmt:		/* CREATE INDEX */
>   			{
>   				IndexStmt  *stmt = (IndexStmt *) parsetree;
> ***************
> *** 2125,2130 ****
> --- 2129,2141 ----
>   			}
>   			break;
>   
> + 		case T_CheckFunctionStmt:
> + 			if (((CheckFunctionStmt *) parsetree)->funcname != NULL)
> + 				tag = "CHECK FUNCTION";
> + 			else
> + 				tag = "CHECK TRIGGER";
> + 			break;
> + 
>   		default:
>   			elog(WARNING, "unrecognized node type: %d",
>   				 (int) nodeTag(parsetree));
> ***************
> *** 2565,2570 ****
> --- 2576,2585 ----
>   			}
>   			break;
>   
> + 		case T_CheckFunctionStmt:
> + 			lev = LOGSTMT_ALL;
> + 			break;
> + 
>   		default:
>   			elog(WARNING, "unrecognized node type: %d",
>   				 (int) nodeTag(parsetree));
> *** ./src/bin/pg_dump/pg_dump.c.orig	2011-11-29 19:09:03.000000000 +0100
> --- ./src/bin/pg_dump/pg_dump.c	2011-11-29 20:04:31.094156626 +0100
> ***************
> *** 5326,5338 ****
>   	int			i_lanplcallfoid;
>   	int			i_laninline;
>   	int			i_lanvalidator;
>   	int			i_lanacl;
>   	int			i_lanowner;
>   
>   	/* Make sure we are in proper schema */
>   	selectSourceSchema("pg_catalog");
>   
> ! 	if (g_fout->remoteVersion >= 90000)
>   	{
>   		/* pg_language has a laninline column */
>   		appendPQExpBuffer(query, "SELECT tableoid, oid, "
> --- 5326,5351 ----
>   	int			i_lanplcallfoid;
>   	int			i_laninline;
>   	int			i_lanvalidator;
> + 	int			i_lanchecker;
>   	int			i_lanacl;
>   	int			i_lanowner;
>   
>   	/* Make sure we are in proper schema */
>   	selectSourceSchema("pg_catalog");
>   
> ! 	if (g_fout->remoteVersion >= 90200)
> ! 	{
> ! 		/* pg_language has a lanchecker column */
> ! 		appendPQExpBuffer(query, "SELECT tableoid, oid, "
> ! 						  "lanname, lanpltrusted, lanplcallfoid, "
> ! 						  "laninline, lanvalidator, lanchecker, lanacl, "
> ! 						  "(%s lanowner) AS lanowner "
> ! 						  "FROM pg_language "
> ! 						  "WHERE lanispl "
> ! 						  "ORDER BY oid",
> ! 						  username_subquery);
> ! 	}
> ! 	else if (g_fout->remoteVersion >= 90000)
>   	{
>   		/* pg_language has a laninline column */
>   		appendPQExpBuffer(query, "SELECT tableoid, oid, "
> ***************
> *** 5409,5414 ****
> --- 5422,5428 ----
>   	/* these may fail and return -1: */
>   	i_laninline = PQfnumber(res, "laninline");
>   	i_lanvalidator = PQfnumber(res, "lanvalidator");
> + 	i_lanchecker = PQfnumber(res, "lanchecker");
>   	i_lanacl = PQfnumber(res, "lanacl");
>   	i_lanowner = PQfnumber(res, "lanowner");
>   
> ***************
> *** 5422,5427 ****
> --- 5436,5445 ----
>   		planginfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_lanname));
>   		planginfo[i].lanpltrusted = *(PQgetvalue(res, i, i_lanpltrusted)) == 't';
>   		planginfo[i].lanplcallfoid = atooid(PQgetvalue(res, i, i_lanplcallfoid));
> + 		if (i_lanchecker >= 0)
> + 			planginfo[i].lanchecker = atooid(PQgetvalue(res, i, i_lanchecker));
> + 		else
> + 			planginfo[i].lanchecker = InvalidOid;
>   		if (i_laninline >= 0)
>   			planginfo[i].laninline = atooid(PQgetvalue(res, i, i_laninline));
>   		else
> ***************
> *** 8597,8602 ****
> --- 8615,8621 ----
>   	char	   *qlanname;
>   	char	   *lanschema;
>   	FuncInfo   *funcInfo;
> + 	FuncInfo   *checkerInfo = NULL;
>   	FuncInfo   *inlineInfo = NULL;
>   	FuncInfo   *validatorInfo = NULL;
>   
> ***************
> *** 8616,8621 ****
> --- 8635,8647 ----
>   	if (funcInfo != NULL && !funcInfo->dobj.dump)
>   		funcInfo = NULL;		/* treat not-dumped same as not-found */
>   
> + 	if (OidIsValid(plang->lanchecker))
> + 	{
> + 		checkerInfo = findFuncByOid(plang->lanchecker);
> + 		if (checkerInfo != NULL && !checkerInfo->dobj.dump)
> + 			checkerInfo = NULL;
> + 	}
> + 
>   	if (OidIsValid(plang->laninline))
>   	{
>   		inlineInfo = findFuncByOid(plang->laninline);
> ***************
> *** 8642,8647 ****
> --- 8668,8674 ----
>   	 * don't, this might not work terribly nicely.
>   	 */
>   	useParams = (funcInfo != NULL &&
> + 				 (checkerInfo != NULL || !OidIsValid(plang->lanchecker)) &&
>   				 (inlineInfo != NULL || !OidIsValid(plang->laninline)) &&
>   				 (validatorInfo != NULL || !OidIsValid(plang->lanvalidator)));
>   
> ***************
> *** 8697,8702 ****
> --- 8724,8739 ----
>   			appendPQExpBuffer(defqry, "%s",
>   							  fmtId(validatorInfo->dobj.name));
>   		}
> + 		if (OidIsValid(plang->lanchecker))
> + 		{
> + 			appendPQExpBuffer(defqry, " CHECK ");
> + 			/* Cope with possibility that checker is in different schema */
> + 			if (checkerInfo->dobj.namespace != funcInfo->dobj.namespace)
> + 				appendPQExpBuffer(defqry, "%s.",
> + 							   fmtId(checkerInfo->dobj.namespace->dobj.name));
> + 			appendPQExpBuffer(defqry, "%s",
> + 							  fmtId(checkerInfo->dobj.name));
> + 		}
>   	}
>   	else
>   	{
> *** ./src/bin/pg_dump/pg_dump.h.orig	2011-11-29 20:05:48.255044631 +0100
> --- ./src/bin/pg_dump/pg_dump.h	2011-11-29 20:05:08.766614345 +0100
> ***************
> *** 387,392 ****
> --- 387,393 ----
>   	Oid			lanplcallfoid;
>   	Oid			laninline;
>   	Oid			lanvalidator;
> + 	Oid			lanchecker;
>   	char	   *lanacl;
>   	char	   *lanowner;		/* name of owner, or empty string */
>   } ProcLangInfo;
> *** ./src/bin/psql/tab-complete.c.orig	2011-11-29 19:20:59.482116921 +0100
> --- ./src/bin/psql/tab-complete.c	2011-11-29 19:21:24.516804592 +0100
> ***************
> *** 1,4 ****
> --- 1,5 ----
>   /*
> +  *
>    * psql - the PostgreSQL interactive terminal
>    *
>    * Copyright (c) 2000-2011, PostgreSQL Global Development Group
> ***************
> *** 727,733 ****
>   #define prev6_wd  (previous_words[5])
>   
>   	static const char *const sql_commands[] = {
> ! 		"ABORT", "ALTER", "ANALYZE", "BEGIN", "CHECKPOINT", "CLOSE", "CLUSTER",
>   		"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
>   		"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN", "FETCH",
>   		"GRANT", "INSERT", "LISTEN", "LOAD", "LOCK", "MOVE", "NOTIFY", "PREPARE",
> --- 728,734 ----
>   #define prev6_wd  (previous_words[5])
>   
>   	static const char *const sql_commands[] = {
> ! 		"ABORT", "ALTER", "ANALYZE", "BEGIN", "CHECK", "CHECKPOINT", "CLOSE", "CLUSTER",
>   		"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
>   		"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN", "FETCH",
>   		"GRANT", "INSERT", "LISTEN", "LOAD", "LOCK", "MOVE", "NOTIFY", "PREPARE",
> ***************
> *** 1524,1529 ****
> --- 1525,1552 ----
>   
>   		COMPLETE_WITH_LIST(list_TRANS);
>   	}
> + 
> + /* CHECK */
> + 	else if (pg_strcasecmp(prev_wd, "CHECK") == 0)
> + 	{
> + 		static const char *const list_CHECK[] =
> + 		{"FUNCTION", "TRIGGER", NULL};
> + 
> + 		COMPLETE_WITH_LIST(list_CHECK);
> + 	}
> + 	else if (pg_strcasecmp(prev3_wd, "CHECK") == 0 &&
> + 			 pg_strcasecmp(prev2_wd, "TRIGGER") == 0)
> + 	{
> + 		COMPLETE_WITH_CONST("ON");
> + 	}
> + 	else if (pg_strcasecmp(prev4_wd, "CHECK") == 0 &&
> + 			 pg_strcasecmp(prev3_wd, "TRIGGER") == 0 &&
> + 			 pg_strcasecmp(prev_wd, "ON") == 0)
> + 	{
> + 		completion_info_charp = prev2_wd;
> + 		COMPLETE_WITH_QUERY(Query_for_list_of_tables_for_trigger);
> + 	}
> + 
>   /* CLUSTER */
>   
>   	/*
> *** ./src/include/catalog/pg_language.h.orig	2011-11-29 19:20:59.483116909 +0100
> --- ./src/include/catalog/pg_language.h	2011-11-29 19:21:24.518804568 +0100
> ***************
> *** 37,42 ****
> --- 37,43 ----
>   	Oid			lanplcallfoid;	/* Call handler for PL */
>   	Oid			laninline;		/* Optional anonymous-block handler function */
>   	Oid			lanvalidator;	/* Optional validation function */
> + 	Oid			lanchecker;	/* Optional checker function */
>   	aclitem		lanacl[1];		/* Access privileges */
>   } FormData_pg_language;
>   
> ***************
> *** 51,57 ****
>    *		compiler constants for pg_language
>    * ----------------
>    */
> ! #define Natts_pg_language				8
>   #define Anum_pg_language_lanname		1
>   #define Anum_pg_language_lanowner		2
>   #define Anum_pg_language_lanispl		3
> --- 52,58 ----
>    *		compiler constants for pg_language
>    * ----------------
>    */
> ! #define Natts_pg_language				9
>   #define Anum_pg_language_lanname		1
>   #define Anum_pg_language_lanowner		2
>   #define Anum_pg_language_lanispl		3
> ***************
> *** 59,78 ****
>   #define Anum_pg_language_lanplcallfoid	5
>   #define Anum_pg_language_laninline		6
>   #define Anum_pg_language_lanvalidator	7
> ! #define Anum_pg_language_lanacl			8
>   
>   /* ----------------
>    *		initial contents of pg_language
>    * ----------------
>    */
>   
> ! DATA(insert OID = 12 ( "internal"	PGUID f f 0 0 2246 _null_ ));
>   DESCR("built-in functions");
>   #define INTERNALlanguageId 12
> ! DATA(insert OID = 13 ( "c"			PGUID f f 0 0 2247 _null_ ));
>   DESCR("dynamically-loaded C functions");
>   #define ClanguageId 13
> ! DATA(insert OID = 14 ( "sql"		PGUID f t 0 0 2248 _null_ ));
>   DESCR("SQL-language functions");
>   #define SQLlanguageId 14
>   
> --- 60,80 ----
>   #define Anum_pg_language_lanplcallfoid	5
>   #define Anum_pg_language_laninline		6
>   #define Anum_pg_language_lanvalidator	7
> ! #define Anum_pg_language_lanchecker	8
> ! #define Anum_pg_language_lanacl			9
>   
>   /* ----------------
>    *		initial contents of pg_language
>    * ----------------
>    */
>   
> ! DATA(insert OID = 12 ( "internal"	PGUID f f 0 0 2246 0 _null_ ));
>   DESCR("built-in functions");
>   #define INTERNALlanguageId 12
> ! DATA(insert OID = 13 ( "c"			PGUID f f 0 0 2247 0 _null_ ));
>   DESCR("dynamically-loaded C functions");
>   #define ClanguageId 13
> ! DATA(insert OID = 14 ( "sql"		PGUID f t 0 0 2248 0 _null_ ));
>   DESCR("SQL-language functions");
>   #define SQLlanguageId 14
>   
> *** ./src/include/catalog/pg_pltemplate.h.orig	2011-11-29 19:20:59.484116897 +0100
> --- ./src/include/catalog/pg_pltemplate.h	2011-11-29 19:21:24.518804568 +0100
> ***************
> *** 36,41 ****
> --- 36,42 ----
>   	text		tmplhandler;	/* name of call handler function */
>   	text		tmplinline;		/* name of anonymous-block handler, or NULL */
>   	text		tmplvalidator;	/* name of validator function, or NULL */
> + 	text		tmplchecker;	/* name of checker function, or NULL */
>   	text		tmpllibrary;	/* path of shared library */
>   	aclitem		tmplacl[1];		/* access privileges for template */
>   } FormData_pg_pltemplate;
> ***************
> *** 51,65 ****
>    *		compiler constants for pg_pltemplate
>    * ----------------
>    */
> ! #define Natts_pg_pltemplate					8
>   #define Anum_pg_pltemplate_tmplname			1
>   #define Anum_pg_pltemplate_tmpltrusted		2
>   #define Anum_pg_pltemplate_tmpldbacreate	3
>   #define Anum_pg_pltemplate_tmplhandler		4
>   #define Anum_pg_pltemplate_tmplinline		5
>   #define Anum_pg_pltemplate_tmplvalidator	6
> ! #define Anum_pg_pltemplate_tmpllibrary		7
> ! #define Anum_pg_pltemplate_tmplacl			8
>   
>   
>   /* ----------------
> --- 52,67 ----
>    *		compiler constants for pg_pltemplate
>    * ----------------
>    */
> ! #define Natts_pg_pltemplate					9
>   #define Anum_pg_pltemplate_tmplname			1
>   #define Anum_pg_pltemplate_tmpltrusted		2
>   #define Anum_pg_pltemplate_tmpldbacreate	3
>   #define Anum_pg_pltemplate_tmplhandler		4
>   #define Anum_pg_pltemplate_tmplinline		5
>   #define Anum_pg_pltemplate_tmplvalidator	6
> ! #define Anum_pg_pltemplate_tmplchecker		7
> ! #define Anum_pg_pltemplate_tmpllibrary		8
> ! #define Anum_pg_pltemplate_tmplacl			9
>   
>   
>   /* ----------------
> ***************
> *** 67,79 ****
>    * ----------------
>    */
>   
> ! DATA(insert ( "plpgsql"		t t "plpgsql_call_handler" "plpgsql_inline_handler" "plpgsql_validator" "$libdir/plpgsql" _null_ ));
> ! DATA(insert ( "pltcl"		t t "pltcl_call_handler" _null_ _null_ "$libdir/pltcl" _null_ ));
> ! DATA(insert ( "pltclu"		f f "pltclu_call_handler" _null_ _null_ "$libdir/pltcl" _null_ ));
> ! DATA(insert ( "plperl"		t t "plperl_call_handler" "plperl_inline_handler" "plperl_validator" "$libdir/plperl" _null_ ));
> ! DATA(insert ( "plperlu"		f f "plperlu_call_handler" "plperlu_inline_handler" "plperlu_validator" "$libdir/plperl" _null_ ));
> ! DATA(insert ( "plpythonu"	f f "plpython_call_handler" "plpython_inline_handler" "plpython_validator" "$libdir/plpython2" _null_ ));
> ! DATA(insert ( "plpython2u"	f f "plpython2_call_handler" "plpython2_inline_handler" "plpython2_validator" "$libdir/plpython2" _null_ ));
> ! DATA(insert ( "plpython3u"	f f "plpython3_call_handler" "plpython3_inline_handler" "plpython3_validator" "$libdir/plpython3" _null_ ));
>   
>   #endif   /* PG_PLTEMPLATE_H */
> --- 69,81 ----
>    * ----------------
>    */
>   
> ! DATA(insert ( "plpgsql"		t t "plpgsql_call_handler" "plpgsql_inline_handler" "plpgsql_validator" "plpgsql_checker" "$libdir/plpgsql" _null_ ));
> ! DATA(insert ( "pltcl"		t t "pltcl_call_handler" _null_ _null_ _null_ "$libdir/pltcl" _null_ ));
> ! DATA(insert ( "pltclu"		f f "pltclu_call_handler" _null_ _null_ _null_ "$libdir/pltcl" _null_ ));
> ! DATA(insert ( "plperl"		t t "plperl_call_handler" "plperl_inline_handler" "plperl_validator" _null_ "$libdir/plperl" _null_ ));
> ! DATA(insert ( "plperlu"		f f "plperlu_call_handler" "plperlu_inline_handler" "plperlu_validator" _null_ "$libdir/plperl" _null_ ));
> ! DATA(insert ( "plpythonu"	f f "plpython_call_handler" "plpython_inline_handler" "plpython_validator" _null_ "$libdir/plpython2" _null_ ));
> ! DATA(insert ( "plpython2u"	f f "plpython2_call_handler" "plpython2_inline_handler" "plpython2_validator" _null_ "$libdir/plpython2" _null_ ));
> ! DATA(insert ( "plpython3u"	f f "plpython3_call_handler" "plpython3_inline_handler" "plpython3_validator" _null_ "$libdir/plpython3" _null_ ));
>   
>   #endif   /* PG_PLTEMPLATE_H */
> *** ./src/include/commands/defrem.h.orig	2011-11-29 19:20:59.486116871 +0100
> --- ./src/include/commands/defrem.h	2011-11-29 19:21:24.519804556 +0100
> ***************
> *** 62,67 ****
> --- 62,68 ----
>   /* commands/functioncmds.c */
>   extern void CreateFunction(CreateFunctionStmt *stmt, const char *queryString);
>   extern void RemoveFunctionById(Oid funcOid);
> + extern void CheckFunction(CheckFunctionStmt *stmt);
>   extern void SetFunctionReturnType(Oid funcOid, Oid newRetType);
>   extern void SetFunctionArgType(Oid funcOid, int argIndex, Oid newArgType);
>   extern void RenameFunction(List *name, List *argtypes, const char *newname);
> *** ./src/include/nodes/nodes.h.orig	2011-11-29 19:20:59.487116858 +0100
> --- ./src/include/nodes/nodes.h	2011-11-29 19:21:24.521804532 +0100
> ***************
> *** 291,296 ****
> --- 291,297 ----
>   	T_IndexStmt,
>   	T_CreateFunctionStmt,
>   	T_AlterFunctionStmt,
> + 	T_CheckFunctionStmt,
>   	T_DoStmt,
>   	T_RenameStmt,
>   	T_RuleStmt,
> *** ./src/include/nodes/parsenodes.h.orig	2011-11-29 19:20:59.489116833 +0100
> --- ./src/include/nodes/parsenodes.h	2011-11-29 19:21:24.523804506 +0100
> ***************
> *** 1734,1739 ****
> --- 1734,1740 ----
>   	List	   *plhandler;		/* PL call handler function (qual. name) */
>   	List	   *plinline;		/* optional inline function (qual. name) */
>   	List	   *plvalidator;	/* optional validator function (qual. name) */
> + 	List	   *plchecker;		/* optional checker function (qual. name) */
>   	bool		pltrusted;		/* PL is trusted */
>   } CreatePLangStmt;
>   
> ***************
> *** 2077,2082 ****
> --- 2078,2096 ----
>   } AlterFunctionStmt;
>   
>   /* ----------------------
> +  *		Check {Function|Trigger} Statement
> +  * ----------------------
> +  */
> + typedef struct CheckFunctionStmt
> + {
> + 	NodeTag		type;
> + 	List	   *funcname;			/* qualified name of checked object */
> + 	List	   *args;			/* types of the arguments */
> + 	char	   *trgname;			/* trigger's name */
> + 	RangeVar	*relation;		/* trigger's relation */
> + } CheckFunctionStmt;
> + 
> + /* ----------------------
>    *		DO Statement
>    *
>    * DoStmt is the raw parser output, InlineCodeBlock is the execution-time API
> *** ./src/pl/plpgsql/src/pl_comp.c.orig	2011-11-29 19:09:03.000000000 +0100
> --- ./src/pl/plpgsql/src/pl_comp.c	2011-11-29 19:42:43.058753779 +0100
> ***************
> *** 115,121 ****
>   static void plpgsql_HashTableInsert(PLpgSQL_function *function,
>   						PLpgSQL_func_hashkey *func_key);
>   static void plpgsql_HashTableDelete(PLpgSQL_function *function);
> - static void delete_function(PLpgSQL_function *func);
>   
>   /* ----------
>    * plpgsql_compile		Make an execution tree for a PL/pgSQL function.
> --- 115,120 ----
> ***************
> *** 175,181 ****
>   			 * Nope, so remove it from hashtable and try to drop associated
>   			 * storage (if not done already).
>   			 */
> ! 			delete_function(function);
>   
>   			/*
>   			 * If the function isn't in active use then we can overwrite the
> --- 174,180 ----
>   			 * Nope, so remove it from hashtable and try to drop associated
>   			 * storage (if not done already).
>   			 */
> ! 			plpgsql_delete_function(function);
>   
>   			/*
>   			 * If the function isn't in active use then we can overwrite the
> ***************
> *** 2426,2432 ****
>   }
>   
>   /*
> !  * delete_function - clean up as much as possible of a stale function cache
>    *
>    * We can't release the PLpgSQL_function struct itself, because of the
>    * possibility that there are fn_extra pointers to it.	We can release
> --- 2425,2431 ----
>   }
>   
>   /*
> !  * plpgsql_delete_function - clean up as much as possible of a stale function cache
>    *
>    * We can't release the PLpgSQL_function struct itself, because of the
>    * possibility that there are fn_extra pointers to it.	We can release
> ***************
> *** 2439,2446 ****
>    * pointers to the same function cache.  Hence be careful not to do things
>    * twice.
>    */
> ! static void
> ! delete_function(PLpgSQL_function *func)
>   {
>   	/* remove function from hash table (might be done already) */
>   	plpgsql_HashTableDelete(func);
> --- 2438,2445 ----
>    * pointers to the same function cache.  Hence be careful not to do things
>    * twice.
>    */
> ! void
> ! plpgsql_delete_function(PLpgSQL_function *func)
>   {
>   	/* remove function from hash table (might be done already) */
>   	plpgsql_HashTableDelete(func);
> *** ./src/pl/plpgsql/src/pl_exec.c.orig	2011-11-29 19:09:03.316459122 +0100
> --- ./src/pl/plpgsql/src/pl_exec.c	2011-11-29 19:37:19.000000000 +0100
> ***************
> *** 210,216 ****
>   static Portal exec_dynquery_with_params(PLpgSQL_execstate *estate,
>   						  PLpgSQL_expr *dynquery, List *params,
>   						  const char *portalname, int cursorOptions);
> ! 
>   
>   /* ----------
>    * plpgsql_exec_function	Called by the call handler for
> --- 210,228 ----
>   static Portal exec_dynquery_with_params(PLpgSQL_execstate *estate,
>   						  PLpgSQL_expr *dynquery, List *params,
>   						  const char *portalname, int cursorOptions);
> ! static void check_row_or_rec(PLpgSQL_execstate *estate, PLpgSQL_row *row, PLpgSQL_rec *rec);
> ! static void check_expr(PLpgSQL_execstate *estate, PLpgSQL_expr *expr);
> ! static void assign_tupdesc_row_or_rec(PLpgSQL_execstate *estate,
> ! 					    PLpgSQL_row *row, PLpgSQL_rec *rec,
> ! 								    TupleDesc tupdesc);
> ! static TupleDesc expr_get_desc(PLpgSQL_execstate *estate,
> ! 						PLpgSQL_expr *query,
> ! 							bool use_element_type,
> ! 							bool expand_record,
> ! 								bool is_expression);
> ! static void var_init_to_null(PLpgSQL_execstate *estate, int varno);
> ! static void check_stmts(PLpgSQL_execstate *estate, List *stmts);
> ! static void check_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt);
>   
>   /* ----------
>    * plpgsql_exec_function	Called by the call handler for
> ***************
> *** 6176,6178 ****
> --- 6188,7242 ----
>   
>   	return portal;
>   }
> + 
> + /*
> +  * Following code ensures a CHECK FUNCTION and CHECK TRIGGER statements for PL/pgSQL
> +  *
> +  */
> + 
> + /*
> +  * append a CONTEXT to error message
> +  */
> + static void
> + check_error_callback(void *arg)
> + {
> + 	PLpgSQL_execstate *estate = (PLpgSQL_execstate *) arg;
> + 
> + 	if (estate->err_stmt != NULL)
> + 	{
> + 		/* translator: last %s is a plpgsql statement type name */
> + 		errcontext("checking of PL/pgSQL function \"%s\" line %d at %s",
> + 				   estate->func->fn_name,
> + 				   estate->err_stmt->lineno,
> + 				   plpgsql_stmt_typename(estate->err_stmt));
> + 	}
> + 	else
> + 		errcontext("checking of PL/pgSQL function \"%s\"",
> + 				   estate->func->fn_name);
> + }
> + 
> + /*
> +  * Check function - it prepare variables and starts a prepare plan walker
> +  *		called by function checker
> +  */
> + void
> + plpgsql_check_function(PLpgSQL_function *func, FunctionCallInfo fcinfo)
> + {
> + 	PLpgSQL_execstate estate;
> + 	ErrorContextCallback plerrcontext;
> + 	int			i;
> + 
> + 	/* Setup error callback for ereport */
> + 	plerrcontext.callback = check_error_callback;
> + 	plerrcontext.arg = &estate;
> + 	plerrcontext.previous = error_context_stack;
> + 	error_context_stack = &plerrcontext;
> + 
> + 	/*
> + 	 * Setup the execution state - we would to reuse some exec routines
> + 	 * so we need a estate
> + 	 */
> + 	plpgsql_estate_setup(&estate, func, (ReturnSetInfo *) fcinfo->resultinfo);
> + 
> + 	/*
> + 	 * Make local execution copies of all the datums
> + 	 */
> + 	for (i = 0; i < estate.ndatums; i++)
> + 		estate.datums[i] = copy_plpgsql_datum(func->datums[i]);
> + 
> + 	/*
> + 	 * Store the actual call argument values into the appropriate variables
> + 	 */
> + 	for (i = 0; i < func->fn_nargs; i++)
> + 	{
> + 		int			n = func->fn_argvarnos[i];
> + 
> + 		switch (estate.datums[n]->dtype)
> + 		{
> + 			case PLPGSQL_DTYPE_VAR:
> + 				{
> + 					var_init_to_null(&estate, n);
> + 				}
> + 				break;
> + 
> + 			case PLPGSQL_DTYPE_ROW:
> + 				{
> + 					PLpgSQL_row *row = (PLpgSQL_row *) estate.datums[n];
> + 
> + 					exec_move_row(&estate, NULL, row, NULL, NULL);
> + 				}
> + 				break;
> + 
> + 			default:
> + 				elog(ERROR, "unrecognized dtype: %d", func->datums[i]->dtype);
> + 		}
> + 	}
> + 
> + 	/*
> + 	 * Now check the toplevel block of statements
> + 	 */
> + 	check_stmt(&estate, (PLpgSQL_stmt *) func->action);
> + 
> + 	/* Cleanup temporary memory */
> + 	plpgsql_destroy_econtext(&estate);
> + 
> + 	/* Pop the error context stack */
> + 	error_context_stack = plerrcontext.previous;
> + }
> + 
> + /*
> +  * Check trigger - prepare fake environments for testing trigger
> +  *
> +  */
> + void
> + plpgsql_check_trigger(PLpgSQL_function *func,
> + 					 TriggerData *trigdata)
> + {
> + 	PLpgSQL_execstate estate;
> + 	ErrorContextCallback plerrcontext;
> + 	PLpgSQL_rec *rec_new,
> + 			   *rec_old;
> + 	int			i;
> + 
> + 	/* Setup error callback for ereport */
> + 	plerrcontext.callback = check_error_callback;
> + 	plerrcontext.arg = &estate;
> + 	plerrcontext.previous = error_context_stack;
> + 	error_context_stack = &plerrcontext;
> + 
> + 	/*
> + 	 * Setup the execution state - we would to reuse some exec routines
> + 	 * so we need a estate
> + 	 */
> + 	plpgsql_estate_setup(&estate, func, NULL);
> + 
> + 	/*
> + 	 * Make local execution copies of all the datums
> + 	 */
> + 	for (i = 0; i < estate.ndatums; i++)
> + 		estate.datums[i] = copy_plpgsql_datum(func->datums[i]);
> + 
> + 	/*
> + 	 * Put the OLD and NEW tuples into record variables
> + 	 *
> + 	 * We make the tupdescs available in both records even though only one may
> + 	 * have a value.  This allows parsing of record references to succeed in
> + 	 * functions that are used for multiple trigger types.	For example, we
> + 	 * might have a test like "if (TG_OP = 'INSERT' and NEW.foo = 'xyz')",
> + 	 * which should parse regardless of the current trigger type.
> + 	 */
> + 	rec_new = (PLpgSQL_rec *) (estate.datums[func->new_varno]);
> + 	rec_new->freetup = false;
> + 	rec_new->freetupdesc = false;
> + 	assign_tupdesc_row_or_rec(&estate, NULL, rec_new, trigdata->tg_relation->rd_att);
> + 
> + 	rec_old = (PLpgSQL_rec *) (estate.datums[func->old_varno]);
> + 	rec_old->freetup = false;
> + 	rec_old->freetupdesc = false;
> + 	assign_tupdesc_row_or_rec(&estate, NULL, rec_old, trigdata->tg_relation->rd_att);
> + 
> + 	/*
> + 	 * Assign the special tg_ variables
> + 	 */
> + 	var_init_to_null(&estate, func->tg_op_varno);
> + 	var_init_to_null(&estate, func->tg_name_varno);
> + 	var_init_to_null(&estate, func->tg_when_varno);
> + 	var_init_to_null(&estate, func->tg_level_varno);
> + 	var_init_to_null(&estate, func->tg_relid_varno);
> + 	var_init_to_null(&estate, func->tg_relname_varno);
> + 	var_init_to_null(&estate, func->tg_table_name_varno);
> + 	var_init_to_null(&estate, func->tg_table_schema_varno);
> + 	var_init_to_null(&estate, func->tg_nargs_varno);
> + 	var_init_to_null(&estate, func->tg_argv_varno);
> + 
> + 	/*
> + 	 * Now check the toplevel block of statements
> + 	 */
> + 	check_stmt(&estate, (PLpgSQL_stmt *) func->action);
> + 
> + 	/* Cleanup temporary memory */
> + 	plpgsql_destroy_econtext(&estate);
> + 
> + 	/* Pop the error context stack */
> + 	error_context_stack = plerrcontext.previous;
> + }
> + 
> + /*
> +  * Verify lvalue
> +  *    It doesn't repeat a checks that are done.
> +  *  Checks a subscript expressions, verify a validity of record's fields
> +  */
> + static void
> + check_target(PLpgSQL_execstate *estate, int varno)
> + {
> + 	PLpgSQL_datum *target = estate->datums[varno];
> + 
> + 	switch (target->dtype)
> + 	{
> + 		case PLPGSQL_DTYPE_VAR:
> + 		case PLPGSQL_DTYPE_REC:
> + 			break;
> + 
> + 		case PLPGSQL_DTYPE_ROW:
> + 			check_row_or_rec(estate, (PLpgSQL_row *) target, NULL);
> + 			break;
> + 
> + 		case PLPGSQL_DTYPE_RECFIELD:
> + 			{
> + 				PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) target;
> + 				PLpgSQL_rec *rec;
> + 				int			fno;
> + 
> + 				rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]);
> + 
> + 				/*
> + 				 * Check that there is already a tuple in the record. We need
> + 				 * that because records don't have any predefined field
> + 				 * structure.
> + 				 */
> + 				if (!HeapTupleIsValid(rec->tup))
> + 					ereport(ERROR,
> + 						  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> + 						   errmsg("record \"%s\" is not assigned to tuple structure",
> + 								  rec->refname)));
> + 
> + 				/*
> + 				 * Get the number of the records field to change and the
> + 				 * number of attributes in the tuple.  Note: disallow system
> + 				 * column names because the code below won't cope.
> + 				 */
> + 				fno = SPI_fnumber(rec->tupdesc, recfield->fieldname);
> + 				if (fno <= 0)
> + 					ereport(ERROR,
> + 							(errcode(ERRCODE_UNDEFINED_COLUMN),
> + 							 errmsg("record \"%s\" has no field \"%s\"",
> + 									rec->refname, recfield->fieldname)));
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_DTYPE_ARRAYELEM:
> + 			{
> + 				/*
> + 				 * Target is an element of an array
> + 				 */
> + 				int			nsubscripts;
> + 				Oid		arrayelemtypeid;
> + 				Oid		arraytypeid;
> + 
> + 				/*
> + 				 * To handle constructs like x[1][2] := something, we have to
> + 				 * be prepared to deal with a chain of arrayelem datums. Chase
> + 				 * back to find the base array datum, and save the subscript
> + 				 * expressions as we go.  (We are scanning right to left here,
> + 				 * but want to evaluate the subscripts left-to-right to
> + 				 * minimize surprises.)
> + 				 */
> + 				nsubscripts = 0;
> + 				do
> + 				{
> + 					PLpgSQL_arrayelem *arrayelem = (PLpgSQL_arrayelem *) target;
> + 
> + 					if (nsubscripts++ >= MAXDIM)
> + 						ereport(ERROR,
> + 								(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
> + 								 errmsg("number of array dimensions (%d) exceeds the maximum allowed (%d)",
> + 										nsubscripts + 1, MAXDIM)));
> + 
> + 					check_expr(estate, arrayelem->subscript);
> + 
> + 					target = estate->datums[arrayelem->arrayparentno];
> + 				} while (target->dtype == PLPGSQL_DTYPE_ARRAYELEM);
> + 
> + 				/* If target is domain over array, reduce to base type */
> + 				arraytypeid = exec_get_datum_type(estate, target);
> + 				arraytypeid = getBaseType(arraytypeid);
> + 
> + 				arrayelemtypeid = get_element_type(arraytypeid);
> + 
> + 				if (!OidIsValid(arrayelemtypeid))
> + 					ereport(ERROR,
> + 							(errcode(ERRCODE_DATATYPE_MISMATCH),
> + 							 errmsg("subscripted object is not an array")));
> + 			}
> + 			break;
> + 	}
> + }
> + 
> + /*
> +  * Check composed lvalue
> +  *    There is nothing to check on rec variables
> +  */
> + static void
> + check_row_or_rec(PLpgSQL_execstate *estate, PLpgSQL_row *row, PLpgSQL_rec *rec)
> + {
> + 	int fnum;
> + 
> + 	/* there are nothing to check on rec now */
> + 	if (row != NULL)
> + 	{
> + 		for (fnum = 0; fnum < row->nfields; fnum++)
> + 		{
> + 			/* skip dropped columns */
> + 			if (row->varnos[fnum] < 0)
> + 				continue;
> + 
> + 			check_target(estate, row->varnos[fnum]);
> + 		}
> + 	}
> + }
> + 
> + /*
> +  * Generate a prepared plan - this is simplyfied copy from pl_exec.c
> +  *   Is not necessary to check simple plan
> +  */
> + static void
> + prepare_expr(PLpgSQL_execstate *estate,
> + 				  PLpgSQL_expr *expr, int cursorOptions)
> + {
> + 	SPIPlanPtr	plan;
> + 
> + 	/* leave when there are not expression */
> + 	if (expr == NULL)
> + 		return;
> + 
> + 	/* leave when plan is created */
> + 	if (expr->plan != NULL)
> + 		return;
> + 
> + 	/*
> + 	 * The grammar can't conveniently set expr->func while building the parse
> + 	 * tree, so make sure it's set before parser hooks need it.
> + 	 */
> + 	expr->func = estate->func;
> + 
> + 	/*
> + 	 * Generate and save the plan
> + 	 */
> + 	plan = SPI_prepare_params(expr->query,
> + 							  (ParserSetupHook) plpgsql_parser_setup,
> + 							  (void *) expr,
> + 							  cursorOptions);
> + 	if (plan == NULL)
> + 	{
> + 		/* Some SPI errors deserve specific error messages */
> + 		switch (SPI_result)
> + 		{
> + 			case SPI_ERROR_COPY:
> + 				ereport(ERROR,
> + 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
> + 						 errmsg("cannot COPY to/from client in PL/pgSQL")));
> + 			case SPI_ERROR_TRANSACTION:
> + 				ereport(ERROR,
> + 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
> + 						 errmsg("cannot begin/end transactions in PL/pgSQL"),
> + 						 errhint("Use a BEGIN block with an EXCEPTION clause instead.")));
> + 			default:
> + 				elog(ERROR, "SPI_prepare_params failed for \"%s\": %s",
> + 					 expr->query, SPI_result_code_string(SPI_result));
> + 		}
> + 	}
> + 
> + 	expr->plan = SPI_saveplan(plan);
> + 	SPI_freeplan(plan);
> + }
> + 
> + /*
> +  * Verify a expression
> +  */
> + static void
> + check_expr(PLpgSQL_execstate *estate, PLpgSQL_expr *expr)
> + {
> + 	TupleDesc tupdesc;
> + 
> + 	if (expr != NULL)
> + 	{
> + 		prepare_expr(estate, expr, 0);
> + 		tupdesc = expr_get_desc(estate, expr, false, false, true);
> + 		ReleaseTupleDesc(tupdesc);
> + 	}
> + }
> + 
> + /*
> +  * We have to assign TupleDesc to all used record variables step by step.
> +  * We would to use a exec routines for query preprocessing, so we must
> +  * to create a typed NULL value, and this value is assigned to record
> +  * variable.
> +  */
> + static void
> + assign_tupdesc_row_or_rec(PLpgSQL_execstate *estate,
> + 					    PLpgSQL_row *row, PLpgSQL_rec *rec,
> + 								    TupleDesc tupdesc)
> + {
> + 	bool	   *nulls;
> + 	HeapTuple  tup;
> + 
> + 	if (tupdesc == NULL)
> + 		elog(ERROR, "tuple descriptor is empty");
> + 
> + 	/*
> + 	 * row variable has assigned TupleDesc already, so don't be processed
> + 	 * here
> + 	 */
> + 	if (rec != NULL)
> + 	{
> + 		PLpgSQL_rec *target = (PLpgSQL_rec *)(estate->datums[rec->dno]);
> + 
> + 		if (target->freetup)
> + 			heap_freetuple(target->tup);
> + 
> + 		if (rec->freetupdesc)
> + 			FreeTupleDesc(target->tupdesc);
> + 
> + 		/* initialize rec by NULLs */
> + 		nulls = (bool *) palloc(tupdesc->natts * sizeof(bool));
> + 		memset(nulls, true, tupdesc->natts * sizeof(bool));
> + 
> + 		target->tupdesc = CreateTupleDescCopy(tupdesc);
> + 		target->freetupdesc = true;
> + 
> + 		tup = heap_form_tuple(tupdesc, NULL, nulls);
> + 		if (HeapTupleIsValid(tup))
> + 		{
> + 			target->tup = tup;
> + 			target->freetup = true;
> + 		}
> + 		else
> + 			elog(ERROR, "cannot to build valid composite value");
> + 	}
> + }
> + 
> + /*
> +  * Assign a tuple descriptor to variable specified by dno
> +  */
> + static void
> + assign_tupdesc_dno(PLpgSQL_execstate *estate, int varno, TupleDesc tupdesc)
> + {
> + 	PLpgSQL_datum *target = estate->datums[varno];
> + 
> + 	if (target->dtype == PLPGSQL_DTYPE_REC)
> + 		assign_tupdesc_row_or_rec(estate, NULL, (PLpgSQL_rec *) target, tupdesc);
> + }
> + 
> + /*
> +  * Returns a tuple descriptor based on existing plan
> +  */
> + static TupleDesc 
> + expr_get_desc(PLpgSQL_execstate *estate,
> + 						PLpgSQL_expr *query,
> + 							bool use_element_type,
> + 							bool expand_record,
> + 								bool is_expression)
> + {
> + 	TupleDesc tupdesc = NULL;
> + 	CachedPlanSource *plansource = NULL;
> + 
> + 	if (query->plan != NULL)
> + 	{
> + 		SPIPlanPtr plan = query->plan;
> + 
> + 		if (plan == NULL || plan->magic != _SPI_PLAN_MAGIC)
> + 			elog(ERROR, "cached plan is not valid plan");
> + 
> + 		if (list_length(plan->plancache_list) != 1)
> + 			elog(ERROR, "plan is not single execution plan");
> + 
> + 		plansource = (CachedPlanSource *) linitial(plan->plancache_list);
> + 
> + 		tupdesc = CreateTupleDescCopy(plansource->resultDesc);
> + 	}
> + 	else
> + 		elog(ERROR, "there are no plan for query: \"%s\"",
> + 							    query->query);
> + 
> + 	/*
> + 	 * try to get a element type, when result is a array (used with FOREACH ARRAY stmt)
> + 	 */
> + 	if (use_element_type)
> + 	{
> + 		Oid elemtype;
> + 		TupleDesc elemtupdesc;
> + 
> + 		/* result should be a array */
> + 		if (tupdesc->natts != 1)
> + 			ereport(ERROR,
> + 				(errcode(ERRCODE_SYNTAX_ERROR),
> + 				 errmsg_plural("query \"%s\" returned %d column",
> + 							   "query \"%s\" returned %d columns",
> + 							   tupdesc->natts,
> + 							   query->query,
> + 							   tupdesc->natts)));
> + 
> + 		/* check the type of the expression - must be an array */
> + 		elemtype = get_element_type(tupdesc->attrs[0]->atttypid);
> + 		if (!OidIsValid(elemtype))
> + 			ereport(ERROR,
> + 				(errcode(ERRCODE_DATATYPE_MISMATCH),
> + 				 errmsg("FOREACH expression must yield an array, not type %s",
> + 						format_type_be(tupdesc->attrs[0]->atttypid))));
> + 
> + 		/* we can't know typmod now */
> + 		elemtupdesc = lookup_rowtype_tupdesc_noerror(elemtype, -1, true);
> + 		if (elemtupdesc != NULL)
> + 		{
> + 			FreeTupleDesc(tupdesc);
> + 			tupdesc = CreateTupleDescCopy(elemtupdesc);
> + 			ReleaseTupleDesc(elemtupdesc);
> + 		}
> + 		else
> + 			elog(ERROR, "cannot to identify real type for record type variable");
> + 	}
> + 
> + 	if (is_expression && tupdesc->natts != 1)
> + 		ereport(ERROR,
> + 				(errcode(ERRCODE_SYNTAX_ERROR),
> + 			  errmsg_plural("query \"%s\" returned %d column",
> + 				   "query \"%s\" returned %d columns",
> + 				   tupdesc->natts,
> + 				   query->query,
> + 				   tupdesc->natts)));
> + 
> + 	/*
> + 	 * One spacial case is when record is assigned to composite type, then 
> + 	 * we should to unpack composite type.
> + 	 */
> + 	if (tupdesc->tdtypeid == RECORDOID &&
> + 			tupdesc->tdtypmod == -1 &&
> + 			tupdesc->natts == 1 && expand_record)
> + 	{
> + 		TupleDesc unpack_tupdesc;
> + 
> + 		unpack_tupdesc = lookup_rowtype_tupdesc_noerror(tupdesc->attrs[0]->atttypid,
> + 								tupdesc->attrs[0]->atttypmod,
> + 											    true);
> + 		if (unpack_tupdesc != NULL)
> + 		{
> + 			FreeTupleDesc(tupdesc);
> + 			tupdesc = CreateTupleDescCopy(unpack_tupdesc);
> + 			ReleaseTupleDesc(unpack_tupdesc);
> + 		}
> + 	}
> + 
> + 	/*
> + 	 * There is special case, when returned tupdesc contains only
> + 	 * unpined record: rec := func_with_out_parameters(). IN this case
> + 	 * we must to dig more deep - we have to find oid of function and
> + 	 * get their parameters,
> + 	 *
> + 	 * This is support for assign statement
> + 	 *     recvar := func_with_out_parameters(..)
> + 	 */
> + 	if (tupdesc->tdtypeid == RECORDOID &&
> + 			tupdesc->tdtypmod == -1 &&
> + 			tupdesc->natts == 1 &&
> + 			tupdesc->attrs[0]->atttypid == RECORDOID &&
> + 			tupdesc->attrs[0]->atttypmod == -1 &&
> + 			expand_record)
> + 	{
> + 		PlannedStmt *_stmt;
> + 		Plan		*_plan;
> + 		TargetEntry *tle;
> + 		CachedPlan *cplan;
> + 
> + 		/*
> + 		 * When tupdesc is related to unpined record, we will try
> + 		 * to check plan if it is just function call and if it is
> + 		 * then we can try to derive a tupledes from function's
> + 		 * description.
> + 		 */
> + 		cplan = GetCachedPlan(plansource, NULL, true);
> + 		_stmt = (PlannedStmt *) linitial(cplan->stmt_list);
> + 
> + 		if (IsA(_stmt, PlannedStmt) && _stmt->commandType == CMD_SELECT)
> + 		{
> + 			_plan = _stmt->planTree;
> + 			if (IsA(_plan, Result) && list_length(_plan->targetlist) == 1)
> + 			{
> + 				tle = (TargetEntry *) linitial(_plan->targetlist);
> + 				if (((Node *) tle->expr)->type == T_FuncExpr)
> + 				{
> + 					FuncExpr *fn = (FuncExpr *) tle->expr;
> + 					FmgrInfo flinfo;
> + 					FunctionCallInfoData fcinfo;
> + 					TupleDesc rd;
> + 					Oid		rt;
> + 
> + 					fmgr_info(fn->funcid, &flinfo);
> + 					flinfo.fn_expr = (Node *) fn;
> + 					fcinfo.flinfo = &flinfo;
> + 
> + 					get_call_result_type(&fcinfo, &rt, &rd);
> + 					if (rd == NULL)
> + 						elog(ERROR, "function does not return composite type is not possible to identify composite type");
> + 
> + 					FreeTupleDesc(tupdesc);
> + 					BlessTupleDesc(rd);
> + 
> + 					tupdesc = rd;
> + 				}
> + 			}
> + 		}
> + 
> + 		ReleaseCachedPlan(cplan, true);
> + 	}
> + 
> + 	return tupdesc;
> + }
> + 
> + /*
> +  * Ensure check for all statements in list
> +  */
> + static void
> + check_stmts(PLpgSQL_execstate *estate, List *stmts)
> + {
> + 	ListCell *lc;
> + 
> + 	foreach(lc, stmts)
> + 	{
> + 		check_stmt(estate, (PLpgSQL_stmt *) lfirst(lc));
> + 	}
> + }
> + 
> + /*
> +  * walk over all statements
> +  */
> + static void
> + check_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
> + {
> + 	TupleDesc	tupdesc = NULL;
> + 	PLpgSQL_function *func;
> + 	ListCell *l;
> + 
> + 	if (stmt == NULL)
> + 		return;
> + 
> + 	estate->err_stmt = stmt;
> + 	func = estate->func;
> + 
> + 	switch ((enum PLpgSQL_stmt_types) stmt->cmd_type)
> + 	{
> + 		case PLPGSQL_STMT_BLOCK:
> + 			{
> + 				PLpgSQL_stmt_block *stmt_block = (PLpgSQL_stmt_block *) stmt;
> + 				int		i;
> + 				PLpgSQL_datum		*d;
> + 
> + 				for (i = 0; i < stmt_block->n_initvars; i++)
> + 				{
> + 					d = func->datums[stmt_block->initvarnos[i]];
> + 
> + 					if (d->dtype == PLPGSQL_DTYPE_VAR)
> + 					{
> + 						PLpgSQL_var *var = (PLpgSQL_var *) d;
> + 
> + 						check_expr(estate, var->default_val);
> + 					}
> + 				}
> + 
> + 				check_stmts(estate, stmt_block->body);
> + 				
> + 				if (stmt_block->exceptions)
> + 				{
> + 					foreach(l, stmt_block->exceptions->exc_list)
> + 					{
> + 						check_stmts(estate, ((PLpgSQL_exception *) lfirst(l))->action);
> + 					}
> + 				}
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_ASSIGN:
> + 			{
> + 				PLpgSQL_stmt_assign *stmt_assign = (PLpgSQL_stmt_assign *) stmt;
> + 
> + 				/* prepare plan if desn't exist yet */
> + 				prepare_expr(estate, stmt_assign->expr, 0);
> + 
> + 				tupdesc = expr_get_desc(estate,
> + 								stmt_assign->expr,
> + 										false,		/* no element type */
> + 										true,		/* expand record */
> + 										true);		/* is expression */
> + 
> + 				/* check target, ensure target can get a result */
> + 				check_target(estate, stmt_assign->varno);
> + 
> + 				/* assign a tupdesc to record variable */
> + 				assign_tupdesc_dno(estate, stmt_assign->varno, tupdesc);
> + 				ReleaseTupleDesc(tupdesc);
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_IF:
> + 			{
> + 				PLpgSQL_stmt_if *stmt_if = (PLpgSQL_stmt_if *) stmt;
> + 				ListCell *l;
> + 
> + 				check_expr(estate, stmt_if->cond);
> + 
> + 				check_stmts(estate, stmt_if->then_body);
> + 
> + 				foreach(l, stmt_if->elsif_list)
> + 				{
> + 					PLpgSQL_if_elsif *elif = (PLpgSQL_if_elsif *) lfirst(l);
> + 
> + 					check_expr(estate, elif->cond);
> + 					check_stmts(estate, elif->stmts);
> + 				}
> + 
> + 				check_stmts(estate, stmt_if->else_body);
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_CASE:
> + 			{
> + 				PLpgSQL_stmt_case *stmt_case = (PLpgSQL_stmt_case *) stmt;
> + 				Oid result_oid;
> + 
> + 				if (stmt_case->t_expr != NULL)
> + 				{
> + 					PLpgSQL_var *t_var = (PLpgSQL_var *) estate->datums[stmt_case->t_varno];
> + 
> + 					/* we need to set hidden variable type */
> + 					prepare_expr(estate, stmt_case->t_expr, 0);
> + 
> + 					tupdesc = expr_get_desc(estate,
> + 									stmt_case->t_expr,
> + 										false,		/* no element type */
> + 										false,		/* expand record */
> + 										true);		/* is expression */
> + 
> + 					result_oid = tupdesc->attrs[0]->atttypid;
> + 
> + 					/*
> + 					 * When expected datatype is different from real, change it. Note that
> + 					 * what we're modifying here is an execution copy of the datum, so
> + 					 * this doesn't affect the originally stored function parse tree.
> + 					 */
> + 
> + 					if (t_var->datatype->typoid != result_oid)
> + 						t_var->datatype = plpgsql_build_datatype(result_oid,
> + 												 -1,
> + 												   estate->func->fn_input_collation);
> + 
> + 					ReleaseTupleDesc(tupdesc);
> + 				}
> + 
> + 				foreach(l, stmt_case->case_when_list)
> + 				{
> + 					PLpgSQL_case_when *cwt = (PLpgSQL_case_when *) lfirst(l);
> + 
> + 					check_expr(estate, cwt->expr);
> + 					check_stmts(estate, cwt->stmts);
> + 				}
> + 
> + 				check_stmts(estate, stmt_case->else_stmts);
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_LOOP:
> + 			check_stmts(estate, ((PLpgSQL_stmt_loop *) stmt)->body);
> + 			break;
> + 
> + 		case PLPGSQL_STMT_WHILE:
> + 			{
> + 				PLpgSQL_stmt_while *stmt_while = (PLpgSQL_stmt_while *) stmt;
> + 
> + 				check_expr(estate, stmt_while->cond);
> + 				check_stmts(estate, stmt_while->body);
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_FORI:
> + 			{
> + 				PLpgSQL_stmt_fori *stmt_fori = (PLpgSQL_stmt_fori *) stmt;
> + 
> + 				check_expr(estate, stmt_fori->lower);
> + 				check_expr(estate, stmt_fori->upper);
> + 				check_expr(estate, stmt_fori->step);
> + 
> + 				check_stmts(estate, stmt_fori->body);
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_FORS:
> + 			{
> + 				PLpgSQL_stmt_fors *stmt_fors = (PLpgSQL_stmt_fors *) stmt;
> + 
> + 				/* we need to set hidden variable type */
> + 				prepare_expr(estate, stmt_fors->query, 0);
> + 
> + 				tupdesc = expr_get_desc(estate,
> + 								stmt_fors->query,
> + 									false,		/* no element type */
> + 									false,		/* expand record */
> + 									false);		/* is expression */
> + 
> + 				check_row_or_rec(estate, stmt_fors->row, stmt_fors->rec);
> + 				assign_tupdesc_row_or_rec(estate, stmt_fors->row, stmt_fors->rec, tupdesc);
> + 
> + 				check_stmts(estate, stmt_fors->body);
> + 				ReleaseTupleDesc(tupdesc);
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_FORC:
> + 			{
> + 				PLpgSQL_stmt_forc *stmt_forc = (PLpgSQL_stmt_forc *) stmt;
> + 				PLpgSQL_var *var = (PLpgSQL_var *) func->datums[stmt_forc->curvar];
> + 
> + 				prepare_expr(estate, stmt_forc->argquery, 0);
> + 
> + 				if (var->cursor_explicit_expr != NULL)
> + 				{
> + 					prepare_expr(estate, var->cursor_explicit_expr,
> + 								    var->cursor_options);
> + 
> + 					tupdesc = expr_get_desc(estate,
> + 									var->cursor_explicit_expr,
> + 										false,		/* no element type */
> + 										false,		/* expand record */
> + 										false);		/* is expression */
> + 
> + 					check_row_or_rec(estate, stmt_forc->row, stmt_forc->rec);
> + 					assign_tupdesc_row_or_rec(estate, stmt_forc->row, stmt_forc->rec, tupdesc);
> + 				}
> + 
> + 				check_stmts(estate, stmt_forc->body);
> + 				if (tupdesc != NULL)
> + 					ReleaseTupleDesc(tupdesc);
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_DYNFORS:
> + 			{
> + 				PLpgSQL_stmt_dynfors * stmt_dynfors = (PLpgSQL_stmt_dynfors *) stmt;
> + 
> + 				if (stmt_dynfors->rec != NULL)
> + 					elog(ERROR, "cannot determinate a result of dynamic SQL");
> + 
> + 				check_expr(estate, stmt_dynfors->query);
> + 
> + 				foreach(l, stmt_dynfors->params)
> + 				{
> + 					check_expr(estate, (PLpgSQL_expr *) lfirst(l));
> + 				}
> + 
> + 				check_stmts(estate, stmt_dynfors->body);
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_FOREACH_A:
> + 			{
> + 				PLpgSQL_stmt_foreach_a *stmt_foreach_a = (PLpgSQL_stmt_foreach_a *) stmt;
> + 
> + 				prepare_expr(estate, stmt_foreach_a->expr, 0);
> + 
> + 				tupdesc = expr_get_desc(estate,
> + 								stmt_foreach_a->expr,
> + 									true,		/* no element type */
> + 									false,		/* expand record */
> + 									true);		/* is expression */
> + 
> + 				check_target(estate, stmt_foreach_a->varno);
> + 				assign_tupdesc_dno(estate, stmt_foreach_a->varno, tupdesc);
> + 				ReleaseTupleDesc(tupdesc);
> + 
> + 				check_stmts(estate, stmt_foreach_a->body);
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_EXIT:
> + 			check_expr(estate, ((PLpgSQL_stmt_exit *) stmt)->cond);
> + 			break;
> + 
> + 		case PLPGSQL_STMT_PERFORM:
> + 			prepare_expr(estate, ((PLpgSQL_stmt_perform *) stmt)->expr, 0);
> + 			break;
> + 
> + 		case PLPGSQL_STMT_RETURN:
> + 			check_expr(estate, ((PLpgSQL_stmt_return *) stmt)->expr);
> + 			break;
> + 
> + 		case PLPGSQL_STMT_RETURN_NEXT:
> + 			check_expr(estate, ((PLpgSQL_stmt_return_next *) stmt)->expr);
> + 			break;
> + 
> + 		case PLPGSQL_STMT_RETURN_QUERY:
> + 			{
> + 				PLpgSQL_stmt_return_query *stmt_rq = (PLpgSQL_stmt_return_query *) stmt;
> + 
> + 				check_expr(estate, stmt_rq->dynquery);
> + 				prepare_expr(estate, stmt_rq->query, 0);
> + 
> + 				foreach(l, stmt_rq->params)
> + 				{
> + 					check_expr(estate, (PLpgSQL_expr *) lfirst(l));
> + 				}
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_RAISE:
> + 			{
> + 				PLpgSQL_stmt_raise *stmt_raise = (PLpgSQL_stmt_raise *) stmt;
> + 				ListCell *current_param;
> + 				char *cp;
> + 
> + 				foreach(l, stmt_raise->params)
> + 				{
> + 					check_expr(estate, (PLpgSQL_expr *) lfirst(l));
> + 				}
> + 
> + 				foreach(l, stmt_raise->options)
> + 				{
> + 					check_expr(estate, (PLpgSQL_expr *) lfirst(l));
> + 				}
> + 
> + 				current_param = list_head(stmt_raise->params);
> + 
> + 				/* ensure any single % has a own parameter */
> + 				if (stmt_raise->message != NULL)
> + 				{
> + 					for (cp = stmt_raise->message; *cp; cp++)
> + 					{
> + 						if (cp[0] == '%')
> + 						{
> + 							if (cp[1] == '%')
> + 							{
> + 								cp++;
> + 								continue;
> + 							}
> + 
> + 							if (current_param == NULL)
> + 								ereport(ERROR,
> + 										(errcode(ERRCODE_SYNTAX_ERROR),
> + 									errmsg("too few parameters specified for RAISE")));
> + 
> + 								current_param = lnext(current_param);
> + 						}
> + 					}
> + 				}
> + 
> + 				if (current_param != NULL)
> + 					ereport(ERROR,
> + 							(errcode(ERRCODE_SYNTAX_ERROR),
> + 							 errmsg("too many parameters specified for RAISE")));
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_EXECSQL:
> + 			{
> + 				PLpgSQL_stmt_execsql *stmt_execsql = (PLpgSQL_stmt_execsql *) stmt;
> + 
> + 				prepare_expr(estate, stmt_execsql->sqlstmt, 0);
> + 				if (stmt_execsql->into)
> + 				{
> + 					tupdesc = expr_get_desc(estate,
> + 								stmt_execsql->sqlstmt,
> + 											false,		/* no element type */
> + 											false,		/* expand record */
> + 											false);		/* is expression */
> + 
> + 					/* check target, ensure target can get a result */
> + 					check_row_or_rec(estate, stmt_execsql->row, stmt_execsql->rec);
> + 					assign_tupdesc_row_or_rec(estate, stmt_execsql->row, stmt_execsql->rec, tupdesc);
> + 					ReleaseTupleDesc(tupdesc);
> + 				}
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_DYNEXECUTE:
> + 			{
> + 				PLpgSQL_stmt_dynexecute *stmt_dynexecute = (PLpgSQL_stmt_dynexecute *) stmt;
> + 
> + 				check_expr(estate, stmt_dynexecute->query);
> + 
> + 				foreach(l, stmt_dynexecute->params)
> + 				{
> + 					check_expr(estate, (PLpgSQL_expr *) lfirst(l));
> + 				}
> + 
> + 				if (stmt_dynexecute->into)
> + 				{
> + 					if (stmt_dynexecute->rec != NULL)
> + 						elog(ERROR, "cannot determinate a result of dynamic SQL");
> + 
> + 					check_row_or_rec(estate, stmt_dynexecute->row, stmt_dynexecute->rec);
> + 				}
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_OPEN:
> + 			{
> + 				PLpgSQL_stmt_open *stmt_open = (PLpgSQL_stmt_open *) stmt;
> + 				PLpgSQL_var *var = (PLpgSQL_var *) func->datums[stmt_open->curvar];
> + 
> + 				if (var->cursor_explicit_expr)
> + 					prepare_expr(estate, var->cursor_explicit_expr,
> + 								   var->cursor_options);
> + 
> + 				prepare_expr(estate, stmt_open->query, 0);
> + 				prepare_expr(estate, stmt_open->argquery, 0);
> + 				check_expr(estate, stmt_open->dynquery);
> + 
> + 				foreach(l, stmt_open->params)
> + 				{
> + 					check_expr(estate, (PLpgSQL_expr *) lfirst(l));
> + 				}
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_GETDIAG:
> + 			{
> + 				PLpgSQL_stmt_getdiag *stmt_getdiag = (PLpgSQL_stmt_getdiag *) stmt;
> + 				ListCell *lc;
> + 
> + 				foreach(lc, stmt_getdiag->diag_items)
> + 				{
> + 					PLpgSQL_diag_item *diag_item = (PLpgSQL_diag_item *) lfirst(lc);
> + 
> + 					check_target(estate, diag_item->target);
> + 				}
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_FETCH:
> + 			{
> + 				PLpgSQL_stmt_fetch *stmt_fetch = (PLpgSQL_stmt_fetch *) stmt;
> + 				PLpgSQL_var *var = (PLpgSQL_var *)(estate->datums[stmt_fetch->curvar]);
> + 
> + 				if (var != NULL && var->cursor_explicit_expr != NULL)
> + 				{
> + 					prepare_expr(estate, var->cursor_explicit_expr, 
> + 									    var->cursor_options);
> + 					tupdesc = expr_get_desc(estate,
> + 								    var->cursor_explicit_expr,
> + 											false,		/* no element type */
> + 											false,		/* expand record */
> + 											false);		/* is expression */
> + 					check_row_or_rec(estate, stmt_fetch->row, stmt_fetch->rec);
> + 					assign_tupdesc_row_or_rec(estate, stmt_fetch->row, stmt_fetch->rec, tupdesc);
> + 					ReleaseTupleDesc(tupdesc);
> + 				}
> + 			}
> + 			break;
> + 
> + 		case PLPGSQL_STMT_CLOSE:
> + 			break;
> + 
> + 		default:
> + 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
> + 			return; /* be compiler quite */
> + 	}
> + }
> + 
> + /*
> +  * Initialize variable to NULL
> +  */
> + static void
> + var_init_to_null(PLpgSQL_execstate *estate, int varno)
> + {
> + 	PLpgSQL_var *var = (PLpgSQL_var *) estate->datums[varno];
> + 	var->value = (Datum) 0;
> + 	var->isnull = true;
> + 	var->freeval = false;
> + }
> *** ./src/pl/plpgsql/src/pl_handler.c.orig	2011-11-29 19:20:59.494116771 +0100
> --- ./src/pl/plpgsql/src/pl_handler.c	2011-11-29 19:21:24.529804431 +0100
> ***************
> *** 312,314 ****
> --- 312,452 ----
>   
>   	PG_RETURN_VOID();
>   }
> + 
> + /* ----------
> +  * plpgsql_checker
> +  *
> +  * This function attempts to check a embeded SQL inside a PL/pgSQL function at
> +  * CHECK FUNCTION time. It should to have one or two parameters. Second
> +  * parameter is a relation (used when function is trigger).
> +  * ----------
> +  */
> + PG_FUNCTION_INFO_V1(plpgsql_checker);
> + 
> + Datum
> + plpgsql_checker(PG_FUNCTION_ARGS)
> + {
> + 	Oid			funcoid = PG_GETARG_OID(0);
> + 	Oid			relid = PG_GETARG_OID(1);
> + 	HeapTuple	tuple;
> + 	FunctionCallInfoData fake_fcinfo;
> + 	FmgrInfo	flinfo;
> + 	TriggerData trigdata;
> + 	int			rc;
> + 	PLpgSQL_function *function;
> + 	PLpgSQL_execstate *cur_estate;
> + 
> + 	Form_pg_proc proc;
> + 	char		functyptype;
> + 	bool	   istrigger = false;
> + 
> + 	/* we don't need to repair a check done by validator */
> + 
> + 	tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcoid));
> + 	if (!HeapTupleIsValid(tuple))
> + 		elog(ERROR, "cache lookup failed for function %u", funcoid);
> + 	proc = (Form_pg_proc) GETSTRUCT(tuple);
> + 
> + 	functyptype = get_typtype(proc->prorettype);
> + 
> + 	if (functyptype == TYPTYPE_PSEUDO)
> + 	{
> + 		/* we assume OPAQUE with no arguments means a trigger */
> + 		if (proc->prorettype == TRIGGEROID ||
> + 			(proc->prorettype == OPAQUEOID && proc->pronargs == 0))
> + 		{
> + 			istrigger = true;
> + 			if (!OidIsValid(relid))
> + 				ereport(ERROR,
> + 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
> + 						 errmsg("PL/pgSQL trigger functions cannot be checked directly"),
> + 						 errhint("use CHECK TRIGGER statement instead")));
> + 		}
> + 	}
> + 
> + 	/*
> + 	 * Connect to SPI manager
> + 	 */
> + 	if ((rc = SPI_connect()) != SPI_OK_CONNECT)
> + 			elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
> + 
> + 	/*
> + 	 * Set up a fake fcinfo with just enough info to satisfy
> + 	 * plpgsql_compile().
> + 	 *
> + 	 * there should be a different real argtypes for polymorphic params
> + 	 */
> + 	MemSet(&fake_fcinfo, 0, sizeof(fake_fcinfo));
> + 	MemSet(&flinfo, 0, sizeof(flinfo));
> + 	fake_fcinfo.flinfo = &flinfo;
> + 	flinfo.fn_oid = funcoid;
> + 	flinfo.fn_mcxt = CurrentMemoryContext;
> + 
> + 	if (istrigger)
> + 	{
> + 		MemSet(&trigdata, 0, sizeof(trigdata));
> + 		trigdata.type = T_TriggerData;
> + 		trigdata.tg_relation = relation_open(relid, AccessShareLock);
> + 		fake_fcinfo.context = (Node *) &trigdata;
> + 	}
> + 
> + 	/* Get a compiled function */
> + 	function = plpgsql_compile(&fake_fcinfo, false);
> + 
> + 	/* Must save and restore prior value of cur_estate */
> + 	cur_estate = function->cur_estate;
> + 
> + 	/* Mark the function as busy, so it can't be deleted from under us */
> + 	function->use_count++;
> + 
> + 
> + 	/* Create a fake runtime environment and prepare plans */
> + 	PG_TRY();
> + 	{
> + 		if (!istrigger)
> + 			plpgsql_check_function(function, &fake_fcinfo);
> + 		else
> + 			plpgsql_check_trigger(function, &trigdata);
> + 	}
> + 	PG_CATCH();
> + 	{
> + 		if (istrigger)
> + 			relation_close(trigdata.tg_relation, AccessShareLock);
> + 
> + 		function->cur_estate = cur_estate;
> + 		function->use_count--;
> + 
> + 		/*
> + 		 * We cannot to preserve instance of this function, because
> + 		 * expressions are not consistent - a tests on simple expression
> + 		 * was be processed newer.
> + 		 */
> + 		plpgsql_delete_function(function);
> + 
> + 		PG_RE_THROW();
> + 	}
> + 	PG_END_TRY();
> + 
> + 	if (istrigger)
> + 		relation_close(trigdata.tg_relation, AccessShareLock);
> + 
> + 	function->cur_estate = cur_estate;
> + 	function->use_count--;
> + 
> + 	/*
> + 	 * We cannot to preserve instance of this function, because
> + 	 * expressions are not consistent - a tests on simple expression
> + 	 * was be processed newer.
> + 	 */
> + 	plpgsql_delete_function(function);
> + 
> + 	/*
> + 	 * Disconnect from SPI manager
> + 	 */
> + 	if ((rc = SPI_finish()) != SPI_OK_FINISH)
> + 			elog(ERROR, "SPI_finish failed: %s", SPI_result_code_string(rc));
> + 
> + 	ReleaseSysCache(tuple);
> + 
> + 	PG_RETURN_VOID();
> + }
> *** ./src/pl/plpgsql/src/plpgsql.h.orig	2011-11-29 19:20:59.500116698 +0100
> --- ./src/pl/plpgsql/src/plpgsql.h	2011-11-29 20:22:19.423516596 +0100
> ***************
> *** 902,907 ****
> --- 902,908 ----
>   extern void plpgsql_adddatum(PLpgSQL_datum *new);
>   extern int	plpgsql_add_initdatums(int **varnos);
>   extern void plpgsql_HashTableInit(void);
> + extern void plpgsql_delete_function(PLpgSQL_function *func);
>   
>   /* ----------
>    * Functions in pl_handler.c
> ***************
> *** 911,916 ****
> --- 912,918 ----
>   extern Datum plpgsql_call_handler(PG_FUNCTION_ARGS);
>   extern Datum plpgsql_inline_handler(PG_FUNCTION_ARGS);
>   extern Datum plpgsql_validator(PG_FUNCTION_ARGS);
> + extern Datum plpgsql_checker(PG_FUNCTION_ARGS);
>   
>   /* ----------
>    * Functions in pl_exec.c
> ***************
> *** 928,933 ****
> --- 930,939 ----
>   extern void exec_get_datum_type_info(PLpgSQL_execstate *estate,
>   						 PLpgSQL_datum *datum,
>   						 Oid *typeid, int32 *typmod, Oid *collation);
> + extern void plpgsql_check_function(PLpgSQL_function *func,
> + 					 FunctionCallInfo fcinfo);
> + extern void plpgsql_check_trigger(PLpgSQL_function *func,
> + 					 TriggerData *trigdata);
>   
>   /* ----------
>    * Functions for namespace handling in pl_funcs.c
> *** ./src/pl/plpgsql/src/plpgsql--unpackaged--1.0.sql.orig	2011-11-29 19:20:59.502116672 +0100
> --- ./src/pl/plpgsql/src/plpgsql--unpackaged--1.0.sql	2011-11-29 19:21:24.533804381 +0100
> ***************
> *** 5,7 ****
> --- 5,8 ----
>   ALTER EXTENSION plpgsql ADD FUNCTION plpgsql_call_handler();
>   ALTER EXTENSION plpgsql ADD FUNCTION plpgsql_inline_handler(internal);
>   ALTER EXTENSION plpgsql ADD FUNCTION plpgsql_validator(oid);
> + ALTER EXTENSION plpgsql ADD FUNCTION plpgsql_checker(oid, regclass);
> *** ./src/test/regress/expected/plpgsql.out.orig	2011-11-29 19:20:59.505116634 +0100
> --- ./src/test/regress/expected/plpgsql.out	2011-11-29 19:21:24.536804342 +0100
> ***************
> *** 302,307 ****
> --- 302,310 ----
>   ' language plpgsql;
>   create trigger tg_hslot_biu before insert or update
>       on HSlot for each row execute procedure tg_hslot_biu();
> + -- check trigger should not fail
> + check trigger tg_hslot_biu on HSlot;
> + NOTICE:  checking function "tg_hslot_biu()"
>   -- ************************************************************
>   -- * BEFORE DELETE on HSlot
>   -- *	- prevent from manual manipulation
> ***************
> *** 635,640 ****
> --- 638,645 ----
>       raise exception ''illegal backlink beginning with %'', mytype;
>   end;
>   ' language plpgsql;
> + -- check function should not fail
> + check function tg_backlink_set(bpchar, bpchar);
>   -- ************************************************************
>   -- * Support function to clear out the backlink field if
>   -- * it still points to specific slot
> ***************
> *** 2802,2807 ****
> --- 2807,2840 ----
>    
>   (1 row)
>   
> + -- check function should not fail
> + check function for_vect();
> + -- recheck after check function
> + select for_vect();
> + NOTICE:  1
> + NOTICE:  2
> + NOTICE:  3
> + NOTICE:  1 BB CC
> + NOTICE:  2 BB CC
> + NOTICE:  3 BB CC
> + NOTICE:  4 BB CC
> + NOTICE:  1
> + NOTICE:  2
> + NOTICE:  3
> + NOTICE:  4
> + NOTICE:  1 BB CC
> + NOTICE:  2 BB CC
> + NOTICE:  3 BB CC
> + NOTICE:  4 BB CC
> + NOTICE:  1 bb cc
> + NOTICE:  2 bb cc
> + NOTICE:  3 bb cc
> + NOTICE:  4 bb cc
> +  for_vect 
> + ----------
> +  
> + (1 row)
> + 
>   -- regression test: verify that multiple uses of same plpgsql datum within
>   -- a SQL command all get mapped to the same $n parameter.  The return value
>   -- of the SELECT is not important, we only care that it doesn't fail with
> ***************
> *** 3283,3288 ****
> --- 3316,3323 ----
>     return;
>   end;
>   $$ language plpgsql;
> + -- check function should not fail
> + check function forc01();
>   select forc01();
>   NOTICE:  5 from c
>   NOTICE:  6 from c
> ***************
> *** 3716,3721 ****
> --- 3751,3758 ----
>     end case;
>   end;
>   $$ language plpgsql immutable;
> + -- check function should not fail
> + check function case_test(bigint);
>   select case_test(1);
>    case_test 
>   -----------
> ***************
> *** 4571,4573 ****
> --- 4608,4942 ----
>   CONTEXT:  PL/pgSQL function "testoa" line 5 at assignment
>   drop function arrayassign1();
>   drop function testoa(x1 int, x2 int, x3 int);
> + --
> + -- check function statement tests
> + --
> + create table t1(a int, b int);
> + create function f1()
> + returns void as $$
> + begin
> +   if false then
> +     update t1 set c = 30;
> +   end if;
> + end;
> + $$ language plpgsql;
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + check function f1();
> + ERROR:  column "c" of relation "t1" does not exist
> + LINE 1: update t1 set c = 30
> +                       ^
> + QUERY:  update t1 set c = 30
> + CONTEXT:  checking of PL/pgSQL function "f1" line 4 at SQL statement
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + drop function f1();
> + create function g1(out a int, out b int)
> + as $$
> +   select 10,20;
> + $$ language sql;
> + create function f1()
> + returns void as $$
> + declare r record;
> + begin
> +   r := g1();
> +   if false then 
> +     raise notice '%', r.c;
> +   end if;
> + end;
> + $$ language plpgsql;
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + check function f1();
> + ERROR:  record "r" has no field "c"
> + CONTEXT:  SQL statement "SELECT r.c"
> + checking of PL/pgSQL function "f1" line 6 at RAISE
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + drop function f1();
> + drop function g1();
> + create function g1(out a int, out b int)
> + returns setof record as $$
> + select * from t1;
> + $$ language sql;
> + create function f1()
> + returns void as $$
> + declare r record;
> + begin
> +   for r in select * from g1()
> +   loop
> +     raise notice '%', r.c;
> +   end loop;
> + end;
> + $$ language plpgsql;
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + check function f1();
> + ERROR:  record "r" has no field "c"
> + CONTEXT:  SQL statement "SELECT r.c"
> + checking of PL/pgSQL function "f1" line 6 at RAISE
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + create or replace function f1()
> + returns void as $$
> + declare r record;
> + begin
> +   for r in select * from g1()
> +   loop
> +     r.c := 20;
> +   end loop;
> + end;
> + $$ language plpgsql;
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + check function f1();
> + ERROR:  record "r" has no field "c"
> + CONTEXT:  checking of PL/pgSQL function "f1" line 6 at assignment
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + drop function f1();
> + drop function g1();
> + create function f1()
> + returns int as $$
> + declare r int;
> + begin
> +   if false then
> +     r := a + b;
> +   end if;
> +   return r;
> + end;
> + $$ language plpgsql;
> + select f1();
> +  f1 
> + ----
> +    
> + (1 row)
> + 
> + check function f1();
> + ERROR:  column "a" does not exist
> + LINE 1: SELECT a + b
> +                ^
> + QUERY:  SELECT a + b
> + CONTEXT:  checking of PL/pgSQL function "f1" line 5 at assignment
> + select f1();
> +  f1 
> + ----
> +    
> + (1 row)
> + 
> + drop function f1();
> + create or replace function f1()
> + returns void as $$
> + begin
> +   if false then
> +     raise notice '%', 1, 2;
> +   end if;
> + end;
> + $$ language plpgsql;
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + check function f1();
> + ERROR:  too many parameters specified for RAISE
> + CONTEXT:  checking of PL/pgSQL function "f1" line 4 at RAISE
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + drop function f1();
> + create or replace function f1()
> + returns void as $$
> + begin
> +   if false then
> +     raise notice '% %';
> +   end if;
> + end;
> + $$ language plpgsql;
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + check function f1();
> + ERROR:  too few parameters specified for RAISE
> + CONTEXT:  checking of PL/pgSQL function "f1" line 4 at RAISE
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + drop function f1();
> + create or replace function f1()
> + returns void as $$
> + declare r int[];
> + begin
> +   if false then
> +     r[c+10] := 20;
> +   end if;
> + end;
> + $$ language plpgsql;
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + check function f1();
> + ERROR:  column "c" does not exist
> + LINE 1: SELECT c+10
> +                ^
> + QUERY:  SELECT c+10
> + CONTEXT:  checking of PL/pgSQL function "f1" line 5 at assignment
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + drop function f1();
> + create or replace function f1()
> + returns void as $$
> + declare r int;
> + begin
> +   if false then
> +     r[10] := 20;
> +   end if;
> + end;
> + $$ language plpgsql;
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + check function f1();
> + ERROR:  subscripted object is not an array
> + CONTEXT:  checking of PL/pgSQL function "f1" line 5 at assignment
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + drop function f1();
> + create type _exception_type as (
> +   state text,
> +   message text,
> +   detail text);
> + create or replace function f1()
> + returns void as $$
> + declare
> +   _exception record;
> + begin
> +   _exception := NULL::_exception_type;
> + exception when others then
> +   get stacked diagnostics
> +         _exception.state = RETURNED_SQLSTATE,
> +         _exception.message = MESSAGE_TEXT,
> +         _exception.detail = PG_EXCEPTION_DETAIL,
> +         _exception.hint = PG_EXCEPTION_HINT;
> + end;
> + $$ language plpgsql;
> + select f1();
> +  f1 
> + ----
> +  
> + (1 row)
> + 
> + check function f1();
> + ERROR:  record "_exception" has no field "hint"
> + CONTEXT:  checking of PL/pgSQL function "f1" line 7 at GET DIAGNOSTICS
> + drop function f1();
> + create or replace function f1_trg()
> + returns trigger as $$
> + begin
> +   if new.a > 10 then
> +     raise notice '%', new.b;
> +     raise notice '%', new.c;
> +   end if;
> +   return new;
> + end;
> + $$ language plpgsql;
> + create trigger t1_f1 before insert on t1
> +   for each row
> +   execute procedure f1_trg();
> + insert into t1 values(6,30);
> + check trigger t1_f1 on t1;
> + NOTICE:  checking function "f1_trg()"
> + ERROR:  record "new" has no field "c"
> + CONTEXT:  SQL statement "SELECT new.c"
> + checking of PL/pgSQL function "f1_trg" line 5 at RAISE
> + insert into t1 values(6,30);
> + create or replace function f1_trg()
> + returns trigger as $$
> + begin
> +   new.a := new.a + 10;
> +   new.b := new.b + 10;
> +   new.c := 30;
> +   return new;
> + end;
> + $$ language plpgsql;
> + -- should to fail
> + check trigger t1_f1 on t1;
> + NOTICE:  checking function "f1_trg()"
> + ERROR:  record "new" has no field "c"
> + CONTEXT:  checking of PL/pgSQL function "f1_trg" line 5 at assignment
> + -- should to fail but not crash
> + insert into t1 values(6,30);
> + ERROR:  record "new" has no field "c"
> + CONTEXT:  PL/pgSQL function "f1_trg" line 5 at assignment
> + create or replace function f1_trg()
> + returns trigger as $$
> + begin
> +   new.a := new.a + 10;
> +   new.b := new.b + 10;
> +   return new;
> + end;
> + $$ language plpgsql;
> + -- ok
> + check trigger t1_f1 on t1;
> + NOTICE:  checking function "f1_trg()"
> + -- ok
> + insert into t1 values(6,30);
> + drop table t1;
> + drop type _exception_type;
> + drop function f1_trg();
> *** ./src/test/regress/sql/plpgsql.sql.orig	2011-11-29 19:20:59.508116598 +0100
> --- ./src/test/regress/sql/plpgsql.sql	2011-11-29 19:21:24.538804318 +0100
> ***************
> *** 366,371 ****
> --- 366,373 ----
>   create trigger tg_hslot_biu before insert or update
>       on HSlot for each row execute procedure tg_hslot_biu();
>   
> + -- check trigger should not fail
> + check trigger tg_hslot_biu on HSlot;
>   
>   -- ************************************************************
>   -- * BEFORE DELETE on HSlot
> ***************
> *** 747,752 ****
> --- 749,757 ----
>   end;
>   ' language plpgsql;
>   
> + -- check function should not fail
> + check function tg_backlink_set(bpchar, bpchar);
> + 
>   
>   -- ************************************************************
>   -- * Support function to clear out the backlink field if
> ***************
> *** 2335,2340 ****
> --- 2340,2352 ----
>   
>   select for_vect();
>   
> + -- check function should not fail
> + check function for_vect();
> + 
> + -- recheck after check function
> + select for_vect();
> + 
> + 
>   -- regression test: verify that multiple uses of same plpgsql datum within
>   -- a SQL command all get mapped to the same $n parameter.  The return value
>   -- of the SELECT is not important, we only care that it doesn't fail with
> ***************
> *** 2714,2719 ****
> --- 2726,2734 ----
>   end;
>   $$ language plpgsql;
>   
> + -- check function should not fail
> + check function forc01();
> + 
>   select forc01();
>   
>   -- try updating the cursor's current row
> ***************
> *** 3048,3053 ****
> --- 3063,3071 ----
>   end;
>   $$ language plpgsql immutable;
>   
> + -- check function should not fail
> + check function case_test(bigint);
> + 
>   select case_test(1);
>   select case_test(2);
>   select case_test(3);
> ***************
> *** 3600,3602 ****
> --- 3618,3862 ----
>   
>   drop function arrayassign1();
>   drop function testoa(x1 int, x2 int, x3 int);
> + 
> + --
> + -- check function statement tests
> + --
> + 
> + create table t1(a int, b int);
> + 
> + create function f1()
> + returns void as $$
> + begin
> +   if false then
> +     update t1 set c = 30;
> +   end if;
> + end;
> + $$ language plpgsql;
> + 
> + select f1();
> + check function f1();
> + select f1();
> + 
> + drop function f1();
> + 
> + create function g1(out a int, out b int)
> + as $$
> +   select 10,20;
> + $$ language sql;
> + 
> + create function f1()
> + returns void as $$
> + declare r record;
> + begin
> +   r := g1();
> +   if false then 
> +     raise notice '%', r.c;
> +   end if;
> + end;
> + $$ language plpgsql;
> + 
> + select f1();
> + check function f1();
> + select f1();
> + 
> + drop function f1();
> + drop function g1();
> + 
> + create function g1(out a int, out b int)
> + returns setof record as $$
> + select * from t1;
> + $$ language sql;
> + 
> + create function f1()
> + returns void as $$
> + declare r record;
> + begin
> +   for r in select * from g1()
> +   loop
> +     raise notice '%', r.c;
> +   end loop;
> + end;
> + $$ language plpgsql;
> + 
> + select f1();
> + check function f1();
> + select f1();
> + 
> + create or replace function f1()
> + returns void as $$
> + declare r record;
> + begin
> +   for r in select * from g1()
> +   loop
> +     r.c := 20;
> +   end loop;
> + end;
> + $$ language plpgsql;
> + 
> + select f1();
> + check function f1();
> + select f1();
> + 
> + drop function f1();
> + drop function g1();
> + 
> + create function f1()
> + returns int as $$
> + declare r int;
> + begin
> +   if false then
> +     r := a + b;
> +   end if;
> +   return r;
> + end;
> + $$ language plpgsql;
> + 
> + select f1();
> + check function f1();
> + select f1();
> + 
> + drop function f1();
> + 
> + create or replace function f1()
> + returns void as $$
> + begin
> +   if false then
> +     raise notice '%', 1, 2;
> +   end if;
> + end;
> + $$ language plpgsql;
> + 
> + select f1();
> + check function f1();
> + select f1();
> + 
> + drop function f1();
> + 
> + create or replace function f1()
> + returns void as $$
> + begin
> +   if false then
> +     raise notice '% %';
> +   end if;
> + end;
> + $$ language plpgsql;
> + 
> + select f1();
> + check function f1();
> + select f1();
> + 
> + drop function f1();
> + 
> + create or replace function f1()
> + returns void as $$
> + declare r int[];
> + begin
> +   if false then
> +     r[c+10] := 20;
> +   end if;
> + end;
> + $$ language plpgsql;
> + 
> + select f1();
> + check function f1();
> + select f1();
> + 
> + drop function f1();
> + 
> + create or replace function f1()
> + returns void as $$
> + declare r int;
> + begin
> +   if false then
> +     r[10] := 20;
> +   end if;
> + end;
> + $$ language plpgsql;
> + 
> + select f1();
> + check function f1();
> + select f1();
> + 
> + drop function f1();
> + 
> + create type _exception_type as (
> +   state text,
> +   message text,
> +   detail text);
> + 
> + create or replace function f1()
> + returns void as $$
> + declare
> +   _exception record;
> + begin
> +   _exception := NULL::_exception_type;
> + exception when others then
> +   get stacked diagnostics
> +         _exception.state = RETURNED_SQLSTATE,
> +         _exception.message = MESSAGE_TEXT,
> +         _exception.detail = PG_EXCEPTION_DETAIL,
> +         _exception.hint = PG_EXCEPTION_HINT;
> + end;
> + $$ language plpgsql;
> + 
> + select f1();
> + check function f1();
> + 
> + drop function f1();
> + 
> + create or replace function f1_trg()
> + returns trigger as $$
> + begin
> +   if new.a > 10 then
> +     raise notice '%', new.b;
> +     raise notice '%', new.c;
> +   end if;
> +   return new;
> + end;
> + $$ language plpgsql;
> + 
> + create trigger t1_f1 before insert on t1
> +   for each row
> +   execute procedure f1_trg();
> + 
> + insert into t1 values(6,30);
> + check trigger t1_f1 on t1;
> + insert into t1 values(6,30);
> + 
> + create or replace function f1_trg()
> + returns trigger as $$
> + begin
> +   new.a := new.a + 10;
> +   new.b := new.b + 10;
> +   new.c := 30;
> +   return new;
> + end;
> + $$ language plpgsql;
> + 
> + -- should to fail
> + check trigger t1_f1 on t1;
> + 
> + -- should to fail but not crash
> + insert into t1 values(6,30);
> + 
> + create or replace function f1_trg()
> + returns trigger as $$
> + begin
> +   new.a := new.a + 10;
> +   new.b := new.b + 10;
> +   return new;
> + end;
> + $$ language plpgsql;
> + 
> + -- ok
> + check trigger t1_f1 on t1;
> + 
> + -- ok
> + insert into t1 values(6,30);
> + 
> + drop table t1;
> + drop type _exception_type;
> + 
> + drop function f1_trg();
> + 

> 
> -- 
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-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +