v35-0005-Alter-table-set-compression.patch

From 71104db9a2cad3fb8f64cb43e7f62ccbbe9a1952 Mon Sep 17 00:00:00 2001
From: dilipkumar <dilipbalaut@gmail.com>
Date: Mon, 15 Mar 2021 15:08:02 +0530
Subject: [PATCH v35 5/7] Alter table set compression

Add support for changing the compression method associated
with a column.  There are only built-in methods so we don't
need to rewrite the table, only the new tuples will be
compressed with the new compression method.

Dilip Kumar based on the patches from Ildus Kurbangaliev.
Design input from Robert Haas and Tomas Vondra.
Reviewed by Robert Haas, Tomas Vondra, Alexander Korotkov and Justin Pryzby
---
 doc/src/sgml/ref/alter_table.sgml           |  16 ++
 src/backend/access/heap/heapam_handler.c    |  22 +++
 src/backend/commands/createas.c             |   3 +-
 src/backend/commands/matview.c              |   3 +-
 src/backend/commands/tablecmds.c            | 228 ++++++++++++++++++++++------
 src/backend/executor/nodeModifyTable.c      |   9 +-
 src/backend/parser/gram.y                   |   9 ++
 src/bin/psql/tab-complete.c                 |   2 +-
 src/include/executor/executor.h             |   3 +-
 src/include/nodes/parsenodes.h              |   3 +-
 src/test/regress/expected/compression.out   |  47 +++++-
 src/test/regress/expected/compression_1.out |  48 +++++-
 src/test/regress/sql/compression.sql        |  20 +++
 13 files changed, 356 insertions(+), 57 deletions(-)

diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index c25ef5a..0bd0c1a 100644
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -54,6 +54,7 @@ ALTER TABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable>
     ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET ( <replaceable class="parameter">attribute_option</replaceable> = <replaceable class="parameter">value</replaceable> [, ... ] )
     ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> RESET ( <replaceable class="parameter">attribute_option</replaceable> [, ... ] )
     ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }
+    ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET COMPRESSION <replaceable class="parameter">compression_method</replaceable>
     ADD <replaceable class="parameter">table_constraint</replaceable> [ NOT VALID ]
     ADD <replaceable class="parameter">table_constraint_using_index</replaceable>
     ALTER CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
@@ -103,6 +104,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
   GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( <replaceable>sequence_options</replaceable> ) ] |
   UNIQUE <replaceable class="parameter">index_parameters</replaceable> |
   PRIMARY KEY <replaceable class="parameter">index_parameters</replaceable> |
+  COMPRESSION <replaceable class="parameter">compression_method</replaceable> |
   REFERENCES <replaceable class="parameter">reftable</replaceable> [ ( <replaceable class="parameter">refcolumn</replaceable> ) ] [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ]
     [ ON DELETE <replaceable class="parameter">referential_action</replaceable> ] [ ON UPDATE <replaceable class="parameter">referential_action</replaceable> ] }
 [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
@@ -384,6 +386,20 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry>
+    <term>
+     <literal>SET COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal>
+    </term>
+    <listitem>
+     <para>
+      This sets the compression method for a column.  The supported compression
+      methods are <literal>pglz</literal> and <literal>lz4</literal>.
+      <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
+      was used when building <productname>PostgreSQL</productname>.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
     <term><literal>ADD <replaceable class="parameter">table_constraint</replaceable> [ NOT VALID ]</literal></term>
     <listitem>
      <para>
diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 7664619..b74ba00 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -2471,6 +2471,28 @@ reform_and_rewrite_tuple(HeapTuple tuple,
 	{
 		if (TupleDescAttr(newTupDesc, i)->attisdropped)
 			isnull[i] = true;
+
+		/*
+		 * Since we are rewriting the table, use this opportunity to
+		 * recompress any compressed attribute with current compression method
+		 * of the attribute.  Basically, if the compression method of the
+		 * compressed varlena is not same as current compression method of the
+		 * attribute then decompress it so that if it need to be compressed
+		 * then it will be compressed with the current compression method of
+		 * the attribute.
+		 */
+		else if (!isnull[i] && TupleDescAttr(newTupDesc, i)->attlen == -1)
+		{
+			struct varlena *new_value;
+			char		cmethod;
+
+			new_value = (struct varlena *) DatumGetPointer(values[i]);
+			cmethod = toast_get_compression_method(new_value);
+
+			if (IsValidCompression(cmethod) &&
+				TupleDescAttr(newTupDesc, i)->attcompression != cmethod)
+				values[i] = PointerGetDatum(detoast_attr(new_value));
+		}
 	}
 
 	copiedTuple = heap_form_tuple(newTupDesc, values, isnull);
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index c4ade98..0489fd0 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -590,7 +590,8 @@ intorel_receive(TupleTableSlot *slot, DestReceiver *self)
 		 */
 		slot = CompareCompressionMethodAndDecompress(slot,
 													 &myState->decompress_tuple_slot,
-													 myState->rel->rd_att);
+													 myState->rel->rd_att,
+													 NULL);
 
 		/*
 		 * Note that the input slot might not be of the type of the target
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index 1e31122..4fc0677 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -495,7 +495,8 @@ transientrel_receive(TupleTableSlot *slot, DestReceiver *self)
 	 */
 	slot = CompareCompressionMethodAndDecompress(slot,
 												 &myState->decompress_tuple_slot,
-												 myState->transientrel->rd_att);
+												 myState->transientrel->rd_att,
+												 NULL);
 
 	/*
 	 * Note that the input slot might not be of the type of the target
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cf90f40..4476e2c 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -528,6 +528,8 @@ static void ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKM
 static void ATExecGenericOptions(Relation rel, List *options);
 static void ATExecSetRowSecurity(Relation rel, bool rls);
 static void ATExecForceNoForceRowSecurity(Relation rel, bool force_rls);
+static ObjectAddress ATExecSetCompression(AlteredTableInfo *tab, Relation rel,
+					 const char *column, Node *newValue, LOCKMODE lockmode);
 
 static void index_copy_data(Relation rel, RelFileNode newrnode);
 static const char *storage_name(char c);
@@ -3973,6 +3975,7 @@ AlterTableGetLockLevel(List *cmds)
 				 */
 			case AT_GenericOptions:
 			case AT_AlterColumnGenericOptions:
+			case AT_SetCompression:
 				cmd_lockmode = AccessExclusiveLock;
 				break;
 
@@ -4500,7 +4503,8 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
 		case AT_DisableRowSecurity:
 		case AT_ForceRowSecurity:
 		case AT_NoForceRowSecurity:
-			ATSimplePermissions(rel, ATT_TABLE);
+		case AT_SetCompression:
+			ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW);
 			/* These commands never recurse */
 			/* No command-specific prep needed */
 			pass = AT_PASS_MISC;
@@ -4908,6 +4912,10 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
 			Assert(rel->rd_rel->relkind == RELKIND_INDEX);
 			ATExecAlterCollationRefreshVersion(rel, cmd->object);
 			break;
+		case AT_SetCompression:
+			address = ATExecSetCompression(tab, rel, cmd->name, cmd->def,
+										   lockmode);
+			break;
 		default:				/* oops */
 			elog(ERROR, "unrecognized alter table type: %d",
 				 (int) cmd->subtype);
@@ -5528,15 +5536,35 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 
 			if (tab->rewrite > 0)
 			{
+				bool		decompressed = false;
+
 				/* Extract data from old tuple */
 				slot_getallattrs(oldslot);
 				ExecClearTuple(newslot);
 
-				/* copy attributes */
-				memcpy(newslot->tts_values, oldslot->tts_values,
-					   sizeof(Datum) * oldslot->tts_nvalid);
-				memcpy(newslot->tts_isnull, oldslot->tts_isnull,
-					   sizeof(bool) * oldslot->tts_nvalid);
+				/*
+				 * Compare the compression method of the compressed data in
+				 * the source tuple with that of target attribute and if those
+				 * are different then decompress those data.
+				 */
+				(void) CompareCompressionMethodAndDecompress(oldslot,
+															 &newslot,
+															 newTupDesc,
+															 &decompressed);
+
+				/*
+				 * copy attributes, if we have decompressed some attribute
+				 * then the values and nulls array is already copied
+				 */
+				if (!decompressed)
+				{
+					memcpy(newslot->tts_values, oldslot->tts_values,
+						   sizeof(Datum) * oldslot->tts_nvalid);
+					memcpy(newslot->tts_isnull, oldslot->tts_isnull,
+						   sizeof(bool) * oldslot->tts_nvalid);
+				}
+				else
+					ExecClearTuple(newslot);
 
 				/* Set dropped attributes to null in new tuple */
 				foreach(lc, dropped_attrs)
@@ -7773,6 +7801,67 @@ ATExecSetOptions(Relation rel, const char *colName, Node *options,
 }
 
 /*
+ * Helper function for ATExecSetStorage and ATExecSetCompression
+ *
+ * Set the attcompression and/or attstorage for the respective index attribute
+ * if the respective input values are valid.
+ */
+static void
+ApplyChangesToIndexes(Relation rel, Relation attrelation, AttrNumber attnum,
+					  char newcompression, char newstorage, LOCKMODE lockmode)
+{
+	HeapTuple	tuple;
+	ListCell   *lc;
+	Form_pg_attribute attrtuple;
+
+	foreach(lc, RelationGetIndexList(rel))
+	{
+		Oid			indexoid = lfirst_oid(lc);
+		Relation	indrel;
+		AttrNumber	indattnum = 0;
+
+		indrel = index_open(indexoid, lockmode);
+
+		for (int i = 0; i < indrel->rd_index->indnatts; i++)
+		{
+			if (indrel->rd_index->indkey.values[i] == attnum)
+			{
+				indattnum = i + 1;
+				break;
+			}
+		}
+
+		if (indattnum == 0)
+		{
+			index_close(indrel, lockmode);
+			continue;
+		}
+
+		tuple = SearchSysCacheCopyAttNum(RelationGetRelid(indrel), indattnum);
+
+		if (HeapTupleIsValid(tuple))
+		{
+			attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
+
+			if (CompressionMethodIsValid(newcompression))
+				attrtuple->attcompression = newcompression;
+
+			if (newstorage != '\0')
+				attrtuple->attstorage = newstorage;
+
+			CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
+
+			InvokeObjectPostAlterHook(RelationRelationId,
+									  RelationGetRelid(rel),
+									  attrtuple->attnum);
+
+			heap_freetuple(tuple);
+		}
+
+		index_close(indrel, lockmode);
+	}
+}
+/*
  * ALTER TABLE ALTER COLUMN SET STORAGE
  *
  * Return value is the address of the modified column
@@ -7787,7 +7876,6 @@ ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE loc
 	Form_pg_attribute attrtuple;
 	AttrNumber	attnum;
 	ObjectAddress address;
-	ListCell   *lc;
 
 	Assert(IsA(newValue, String));
 	storagemode = strVal(newValue);
@@ -7851,47 +7939,8 @@ ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE loc
 	 * Apply the change to indexes as well (only for simple index columns,
 	 * matching behavior of index.c ConstructTupleDescriptor()).
 	 */
-	foreach(lc, RelationGetIndexList(rel))
-	{
-		Oid			indexoid = lfirst_oid(lc);
-		Relation	indrel;
-		AttrNumber	indattnum = 0;
-
-		indrel = index_open(indexoid, lockmode);
-
-		for (int i = 0; i < indrel->rd_index->indnatts; i++)
-		{
-			if (indrel->rd_index->indkey.values[i] == attnum)
-			{
-				indattnum = i + 1;
-				break;
-			}
-		}
-
-		if (indattnum == 0)
-		{
-			index_close(indrel, lockmode);
-			continue;
-		}
-
-		tuple = SearchSysCacheCopyAttNum(RelationGetRelid(indrel), indattnum);
-
-		if (HeapTupleIsValid(tuple))
-		{
-			attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
-			attrtuple->attstorage = newstorage;
-
-			CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
-
-			InvokeObjectPostAlterHook(RelationRelationId,
-									  RelationGetRelid(rel),
-									  attrtuple->attnum);
-
-			heap_freetuple(tuple);
-		}
-
-		index_close(indrel, lockmode);
-	}
+	ApplyChangesToIndexes(rel, attrelation, attnum, InvalidCompressionMethod,
+						  newstorage, lockmode);
 
 	table_close(attrelation, RowExclusiveLock);
 
@@ -15017,6 +15066,89 @@ ATExecGenericOptions(Relation rel, List *options)
 }
 
 /*
+ * ALTER TABLE ALTER COLUMN SET COMPRESSION
+ *
+ * Return value is the address of the modified column
+ */
+static ObjectAddress
+ATExecSetCompression(AlteredTableInfo *tab,
+					 Relation rel,
+					 const char *column,
+					 Node *newValue,
+					 LOCKMODE lockmode)
+{
+	Relation	attrel;
+	HeapTuple	tuple;
+	Form_pg_attribute atttableform;
+	AttrNumber	attnum;
+	char	   *compression;
+	char		typstorage;
+	Oid			cmoid;
+	Datum		values[Natts_pg_attribute];
+	bool		nulls[Natts_pg_attribute];
+	bool		replace[Natts_pg_attribute];
+	ObjectAddress address;
+
+	Assert(IsA(newValue, String));
+	compression = strVal(newValue);
+
+	attrel = table_open(AttributeRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheAttName(RelationGetRelid(rel), column);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						column, RelationGetRelationName(rel))));
+
+	/* prevent them from altering a system attribute */
+	atttableform = (Form_pg_attribute) GETSTRUCT(tuple);
+	attnum = atttableform->attnum;
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"", column)));
+
+	typstorage = get_typstorage(atttableform->atttypid);
+
+	/* prevent from setting compression methods for uncompressible type */
+	if (!IsStorageCompressible(typstorage))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					errmsg("column data type %s does not support compression",
+						format_type_be(atttableform->atttypid))));
+
+	/* initialize buffers for new tuple values */
+	memset(values, 0, sizeof(values));
+	memset(nulls, false, sizeof(nulls));
+	memset(replace, false, sizeof(replace));
+
+	/* get the attribute compression method. */
+	cmoid = GetAttributeCompression(atttableform, compression);
+
+	atttableform->attcompression = cmoid;
+	CatalogTupleUpdate(attrel, &tuple->t_self, tuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel),
+							  atttableform->attnum);
+
+	ReleaseSysCache(tuple);
+
+	/* apply changes to the index column as well */
+	ApplyChangesToIndexes(rel, attrel, attnum, cmoid, '\0', lockmode);
+	table_close(attrel, RowExclusiveLock);
+
+	/* make changes visible */
+	CommandCounterIncrement();
+
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), atttableform->attnum);
+	return address;
+}
+
+
+/*
  * Preparation phase for SET LOGGED/UNLOGGED
  *
  * This verifies that we're not trying to change a temp table.  Also,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index dfedd70..cafd772 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2048,7 +2048,8 @@ ExecPrepareTupleRouting(ModifyTableState *mtstate,
 TupleTableSlot *
 CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
 									  TupleTableSlot **outslot,
-									  TupleDesc targetTupDesc)
+									  TupleDesc targetTupDesc,
+									  bool *decompressed)
 {
 	int			i;
 	int			attnum;
@@ -2143,6 +2144,9 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
 		if (TTS_SHOULDFREE(slot))
 			ExecMaterializeSlot(newslot);
 
+		if (decompressed != NULL)
+			*decompressed = true;
+
 		*outslot = newslot;
 
 		return newslot;
@@ -2367,7 +2371,8 @@ ExecModifyTable(PlanState *pstate)
 		 */
 		slot = CompareCompressionMethodAndDecompress(slot,
 									&node->mt_decompress_tuple_slot,
-									resultRelInfo->ri_RelationDesc->rd_att);
+									resultRelInfo->ri_RelationDesc->rd_att,
+									NULL);
 
 		switch (operation)
 		{
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 9d923b5..5c4e779 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2308,6 +2308,15 @@ alter_table_cmd:
 					n->missing_ok = true;
 					$$ = (Node *)n;
 				}
+			/* ALTER TABLE <name> ALTER [COLUMN] <colname> SET (COMPRESSION <cm>) */
+			| ALTER opt_column ColId SET optColumnCompression
+				{
+					AlterTableCmd *n = makeNode(AlterTableCmd);
+					n->subtype = AT_SetCompression;
+					n->name = $3;
+					n->def = (Node *) makeString($5);
+					$$ = (Node *)n;
+				}
 			/* ALTER TABLE <name> DROP [COLUMN] IF EXISTS <colname> [RESTRICT|CASCADE] */
 			| DROP opt_column IF_P EXISTS ColId opt_drop_behavior
 				{
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 9f0208a..07ba55f 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2115,7 +2115,7 @@ psql_completion(const char *text, int start, int end)
 	/* ALTER TABLE ALTER [COLUMN] <foo> SET */
 	else if (Matches("ALTER", "TABLE", MatchAny, "ALTER", "COLUMN", MatchAny, "SET") ||
 			 Matches("ALTER", "TABLE", MatchAny, "ALTER", MatchAny, "SET"))
-		COMPLETE_WITH("(", "DEFAULT", "NOT NULL", "STATISTICS", "STORAGE");
+		COMPLETE_WITH("(", "COMPRESSION", "DEFAULT", "NOT NULL", "STATISTICS", "STORAGE");
 	/* ALTER TABLE ALTER [COLUMN] <foo> SET ( */
 	else if (Matches("ALTER", "TABLE", MatchAny, "ALTER", "COLUMN", MatchAny, "SET", "(") ||
 			 Matches("ALTER", "TABLE", MatchAny, "ALTER", MatchAny, "SET", "("))
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index 483b9f9..65a2f8d 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -623,5 +623,6 @@ extern void CheckSubscriptionRelkind(char relkind, const char *nspname,
 									 const char *relname);
 extern TupleTableSlot *CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
 															 TupleTableSlot **outslot,
-															 TupleDesc targetTupDesc);
+															 TupleDesc targetTupDesc,
+															 bool *decompressed);
 #endif							/* EXECUTOR_H  */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 19d2ba2..f9a87de 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1901,7 +1901,8 @@ typedef enum AlterTableType
 	AT_AddIdentity,				/* ADD IDENTITY */
 	AT_SetIdentity,				/* SET identity column options */
 	AT_DropIdentity,			/* DROP IDENTITY */
-	AT_AlterCollationRefreshVersion /* ALTER COLLATION ... REFRESH VERSION */
+	AT_AlterCollationRefreshVersion, /* ALTER COLLATION ... REFRESH VERSION */
+	AT_SetCompression			/* SET COMPRESSION */
 } AlterTableType;
 
 typedef struct ReplicaIdentityStmt
diff --git a/src/test/regress/expected/compression.out b/src/test/regress/expected/compression.out
index 1773aeb..f206a69 100644
--- a/src/test/regress/expected/compression.out
+++ b/src/test/regress/expected/compression.out
@@ -228,12 +228,57 @@ CREATE TABLE cmdata2 (f1 text);
 --------+------+-----------+----------+---------+----------+-------------+--------------+-------------
  f1     | text |           |          |         | extended | lz4         |              | 
 
+-- test alter compression method
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4;
+INSERT INTO cmdata VALUES (repeat('123456789',4004));
+\d+ cmdata
+                                        Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | lz4         |              | 
+Indexes:
+    "idx" btree (f1)
+
+SELECT pg_column_compression(f1) FROM cmdata;
+ pg_column_compression 
+-----------------------
+ pglz
+ lz4
+(2 rows)
+
+-- test alter compression method for the materialized view
+ALTER MATERIALIZED VIEW mv ALTER COLUMN x SET COMPRESSION lz4;
+\d+ mv
+                                    Materialized view "public.mv"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ x      | text |           |          |         | extended | lz4         |              | 
+View definition:
+ SELECT cmdata1.f1 AS x
+   FROM cmdata1;
+
+-- test alter compression method for the partitioned table
+ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
+-- new data should be compressed with the current compression method
+INSERT INTO cmpart VALUES (repeat('123456789',1004));
+INSERT INTO cmpart VALUES (repeat('123456789',4004));
+SELECT pg_column_compression(f1) FROM cmpart;
+ pg_column_compression 
+-----------------------
+ lz4
+ pglz
+ pglz
+ lz4
+(4 rows)
+
 -- check data is ok
 SELECT length(f1) FROM cmdata;
  length 
 --------
   10000
-(1 row)
+  36036
+(2 rows)
 
 SELECT length(f1) FROM cmdata1;
  length 
diff --git a/src/test/regress/expected/compression_1.out b/src/test/regress/expected/compression_1.out
index 136e750..2292870 100644
--- a/src/test/regress/expected/compression_1.out
+++ b/src/test/regress/expected/compression_1.out
@@ -227,12 +227,58 @@ CREATE TABLE cmdata2 (f1 text);
 --------+------+-----------+----------+---------+----------+-------------+--------------+-------------
  f1     | text |           |          |         | extended | pglz        |              | 
 
+-- test alter compression method
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4;
+ERROR:  unsupported LZ4 compression method
+DETAIL:  This functionality requires the server to be built with lz4 support.
+HINT:  You need to rebuild PostgreSQL using --with-lz4.
+INSERT INTO cmdata VALUES (repeat('123456789',4004));
+\d+ cmdata
+                                        Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | pglz        |              | 
+Indexes:
+    "idx" btree (f1)
+
+SELECT pg_column_compression(f1) FROM cmdata;
+ pg_column_compression 
+-----------------------
+ pglz
+ pglz
+(2 rows)
+
+-- test alter compression method for the materialized view
+ALTER MATERIALIZED VIEW mv ALTER COLUMN x SET COMPRESSION lz4;
+ERROR:  relation "mv" does not exist
+\d+ mv
+-- test alter compression method for the partitioned table
+ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ERROR:  relation "cmpart1" does not exist
+ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
+ERROR:  unsupported LZ4 compression method
+DETAIL:  This functionality requires the server to be built with lz4 support.
+HINT:  You need to rebuild PostgreSQL using --with-lz4.
+-- new data should be compressed with the current compression method
+INSERT INTO cmpart VALUES (repeat('123456789',1004));
+ERROR:  relation "cmpart" does not exist
+LINE 1: INSERT INTO cmpart VALUES (repeat('123456789',1004));
+                    ^
+INSERT INTO cmpart VALUES (repeat('123456789',4004));
+ERROR:  relation "cmpart" does not exist
+LINE 1: INSERT INTO cmpart VALUES (repeat('123456789',4004));
+                    ^
+SELECT pg_column_compression(f1) FROM cmpart;
+ERROR:  relation "cmpart" does not exist
+LINE 1: SELECT pg_column_compression(f1) FROM cmpart;
+                                              ^
 -- check data is ok
 SELECT length(f1) FROM cmdata;
  length 
 --------
   10000
-(1 row)
+  36036
+(2 rows)
 
 SELECT length(f1) FROM cmdata1;
 ERROR:  relation "cmdata1" does not exist
diff --git a/src/test/regress/sql/compression.sql b/src/test/regress/sql/compression.sql
index 1834ba7..12cbfe8 100644
--- a/src/test/regress/sql/compression.sql
+++ b/src/test/regress/sql/compression.sql
@@ -100,6 +100,26 @@ DROP TABLE cmdata2;
 CREATE TABLE cmdata2 (f1 text);
 \d+ cmdata2
 
+-- test alter compression method
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4;
+INSERT INTO cmdata VALUES (repeat('123456789',4004));
+\d+ cmdata
+SELECT pg_column_compression(f1) FROM cmdata;
+
+-- test alter compression method for the materialized view
+ALTER MATERIALIZED VIEW mv ALTER COLUMN x SET COMPRESSION lz4;
+\d+ mv
+
+-- test alter compression method for the partitioned table
+ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
+
+-- new data should be compressed with the current compression method
+INSERT INTO cmpart VALUES (repeat('123456789',1004));
+INSERT INTO cmpart VALUES (repeat('123456789',4004));
+
+SELECT pg_column_compression(f1) FROM cmpart;
+
 -- check data is ok
 SELECT length(f1) FROM cmdata;
 SELECT length(f1) FROM cmdata1;
-- 
1.8.3.1