Re: Add support for DEFAULT specification in COPY FROM

Alexander Law <exclusion@gmail.com>

From: Alexander Lakhin <exclusion@gmail.com>
To: Andrew Dunstan <andrew@dunslane.net>, Israel Barth Rubio <barthisrael@gmail.com>, Zhihong Yu <zyu@yugabyte.com>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2023-03-15T17:00:00Z
Lists: pgsql-hackers
Hello,
13.03.2023 17:15, Andrew Dunstan wrote:
>
> On 2022-12-02 Fr 09:11, Israel Barth Rubio wrote:
>> Hello all,
>>
>> I'm submitting a new version of the patch. Instead of changing signature
>> of several functions in order to use the defaults parameter, it is now storing
>> that in the cstate structure, which is already passed to all functions that
>> were previously modified.
>>
>
> Thanks, committed.

Please look at the query:
create table t (f1 int);
copy t from stdin with (format csv, default '\D');
1,\D

that invokes an assertion failure after 9f8377f7a:
Core was generated by `postgres: law regression [local] 
COPY                                         '.
Program terminated with signal SIGABRT, Aborted.

warning: Section `.reg-xstate/3253881' in core file too small.
#0  __pthread_kill_implementation (no_tid=0, signo=6, threadid=140665061189440) 
at ./nptl/pthread_kill.c:44
44      ./nptl/pthread_kill.c: No such file or directory.
(gdb) bt
#0  __pthread_kill_implementation (no_tid=0, signo=6, threadid=140665061189440) 
at ./nptl/pthread_kill.c:44
#1  __pthread_kill_internal (signo=6, threadid=140665061189440) at 
./nptl/pthread_kill.c:78
#2  __GI___pthread_kill (threadid=140665061189440, signo=signo@entry=6) at 
./nptl/pthread_kill.c:89
#3  0x00007fef2250e476 in __GI_raise (sig=sig@entry=6) at 
../sysdeps/posix/raise.c:26
#4  0x00007fef224f47f3 in __GI_abort () at ./stdlib/abort.c:79
#5  0x00005600fd395750 in ExceptionalCondition (
     conditionName=conditionName@entry=0x5600fd3fa751 "n >= 0 && n < list->length",
     fileName=fileName@entry=0x5600fd416db8 
"../../../src/include/nodes/pg_list.h", lineNumber=lineNumber@entry=280)
     at assert.c:66
#6  0x00005600fd02626d in list_nth_cell (n=<optimized out>, list=<optimized out>)
     at ../../../src/include/nodes/pg_list.h:280
#7  list_nth_int (n=<optimized out>, list=<optimized out>) at 
../../../src/include/nodes/pg_list.h:313
#8  CopyReadAttributesCSV (cstate=<optimized out>) at copyfromparse.c:1905
#9  0x00005600fd0265a5 in NextCopyFromRawFields (cstate=0x5600febdd238, 
fields=0x7fff12ef7130, nfields=0x7fff12ef712c)
     at copyfromparse.c:833
#10 0x00005600fd0267f9 in NextCopyFrom (cstate=cstate@entry=0x5600febdd238, 
econtext=econtext@entry=0x5600fec9c5c8,
     values=0x5600febdd5c8, nulls=0x5600febdd5d0) at copyfromparse.c:885
#11 0x00005600fd0234db in CopyFrom (cstate=cstate@entry=0x5600febdd238) at 
copyfrom.c:989
#12 0x00005600fd0222e5 in DoCopy (pstate=0x5600febdc568, stmt=0x5600febb2d58, 
stmt_location=0, stmt_len=49,
     processed=0x7fff12ef7340) at copy.c:308
#13 0x00005600fd25c5e9 in standard_ProcessUtility (pstmt=0x5600febb2e78,
     queryString=0x5600febb2178 "copy t from stdin with (format csv, default 
'\\D');", readOnlyTree=<optimized out>,
     context=PROCESS_UTILITY_TOPLEVEL, params=0x0, queryEnv=0x0, 
dest=0x5600febb3138, qc=0x7fff12ef7600)
     at utility.c:742
#14 0x00005600fd25a9f1 in PortalRunUtility (portal=portal@entry=0x5600fec4ea48, 
pstmt=pstmt@entry=0x5600febb2e78,
     isTopLevel=isTopLevel@entry=true, 
setHoldSnapshot=setHoldSnapshot@entry=false, dest=dest@entry=0x5600febb3138,
     qc=qc@entry=0x7fff12ef7600) at pquery.c:1158
#15 0x00005600fd25ab2d in PortalRunMulti (portal=portal@entry=0x5600fec4ea48, 
isTopLevel=isTopLevel@entry=true,
     setHoldSnapshot=setHoldSnapshot@entry=false, dest=dest@entry=0x5600febb3138,
     altdest=altdest@entry=0x5600febb3138, qc=qc@entry=0x7fff12ef7600) at 
pquery.c:1315
#16 0x00005600fd25b1c1 in PortalRun (portal=portal@entry=0x5600fec4ea48, 
count=count@entry=9223372036854775807,
     isTopLevel=isTopLevel@entry=true, run_once=run_once@entry=true, 
dest=dest@entry=0x5600febb3138,
     altdest=altdest@entry=0x5600febb3138, qc=0x7fff12ef7600) at pquery.c:791
#17 0x00005600fd256f34 in exec_simple_query (
     query_string=0x5600febb2178 "copy t from stdin with (format csv, default 
'\\D');") at postgres.c:1240
#18 0x00005600fd258ae7 in PostgresMain (dbname=<optimized out>, 
username=<optimized out>) at postgres.c:4572
#19 0x00005600fd1c2d3f in BackendRun (port=0x5600febe05c0, port=0x5600febe05c0) 
at postmaster.c:4461
#20 BackendStartup (port=0x5600febe05c0) at postmaster.c:4189
#21 ServerLoop () at postmaster.c:1779
#22 0x00005600fd1c3d63 in PostmasterMain (argc=argc@entry=3, 
argv=argv@entry=0x5600febad640) at postmaster.c:1463
#23 0x00005600fced4fc6 in main (argc=3, argv=0x5600febad640) at main.c:200

Best regards,
Alexander

Commits

  1. Add a DEFAULT option to COPY FROM