Allow specifying STORAGE attribute for a new table

petere · petere · commit 784cedda0604 · 2022-07-13T12:21:45.000+02:00
Previously, the STORAGE specification was only available in ALTER TABLE. This makes it available in CREATE TABLE as well. Also make the code and the documentation for STORAGE and COMPRESSION attributes consistent. Author: Teodor Sigaev <teodor@sigaev.ru> Author: Aleksander Alekseev <aleksander@timescale.com> Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com> Reviewed-by: wenjing zeng <wjzeng2012@gmail.com> Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Discussion: https://postgr.es/m/de83407a-ae3d-a8e1-a788-920eb334f25b@sigaev.ru
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
@@ -367,7 +367,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
 
    <varlistentry>
     <term>
-     <literal>SET STORAGE</literal>
+     <literal>SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }</literal>
      <indexterm>
       <primary>TOAST</primary>
       <secondary>per-column storage settings</secondary>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
@@ -22,7 +22,7 @@ PostgreSQL documentation
  <refsynopsisdiv>
 <synopsis>
 CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] <replaceable class="parameter">table_name</replaceable> ( [
-  { <replaceable class="parameter">column_name</replaceable> <replaceable class="parameter">data_type</replaceable> [ COMPRESSION <replaceable>compression_method</replaceable> ] [ COLLATE <replaceable>collation</replaceable> ] [ <replaceable class="parameter">column_constraint</replaceable> [ ... ] ]
+  { <replaceable class="parameter">column_name</replaceable> <replaceable class="parameter">data_type</replaceable> [ STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN } ] [ COMPRESSION <replaceable>compression_method</replaceable> ] [ COLLATE <replaceable>collation</replaceable> ] [ <replaceable class="parameter">column_constraint</replaceable> [ ... ] ]
     | <replaceable>table_constraint</replaceable>
     | LIKE <replaceable>source_table</replaceable> [ <replaceable>like_option</replaceable> ... ] }
     [, ... ]
@@ -297,6 +297,33 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term>
+     <literal>STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }</literal>
+     <indexterm>
+      <primary>TOAST</primary>
+      <secondary>per-column storage settings</secondary>
+     </indexterm>
+    </term>
+    <listitem>
+     <para>
+      This form sets the storage mode for the column. This controls whether this
+      column is held inline or in a secondary <acronym>TOAST</acronym> table,
+      and whether the data should be compressed or not. <literal>PLAIN</literal>
+      must be used for fixed-length values such as <type>integer</type> and is
+      inline, uncompressed. <literal>MAIN</literal> is for inline, compressible
+      data. <literal>EXTERNAL</literal> is for external, uncompressed data, and
+      <literal>EXTENDED</literal> is for external, compressed data.
+      <literal>EXTENDED</literal> is the default for most data types that
+      support non-<literal>PLAIN</literal> storage. Use of
+      <literal>EXTERNAL</literal> will make substring operations on very large
+      <type>text</type> and <type>bytea</type> values run faster, at the penalty
+      of increased storage space. See <xref linkend="storage-toast"/> for more
+      information.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
     <listitem>
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
@@ -593,7 +593,7 @@ 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,
+static ObjectAddress ATExecSetCompression(Relation rel,
 										  const char *column, Node *newValue, LOCKMODE lockmode);
 
 static void index_copy_data(Relation rel, RelFileLocator newrlocator);
@@ -633,6 +633,7 @@ static void refuseDupeIndexAttach(Relation parentIdx, Relation partIdx,
 static List *GetParentedForeignKeyRefs(Relation partition);
 static void ATDetachCheckNoForeignKeyRefs(Relation partition);
 static char GetAttributeCompression(Oid atttypid, char *compression);
+static char GetAttributeStorage(Oid atttypid, const char *storagemode);
 
 
 /* ----------------------------------------------------------------
@@ -931,6 +932,9 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 		if (colDef->compression)
 			attr->attcompression = GetAttributeCompression(attr->atttypid,
 														   colDef->compression);
+
+		if (colDef->storage_name)
+			attr->attstorage = GetAttributeStorage(attr->atttypid, colDef->storage_name);
 	}
 
 	/*
@@ -4963,8 +4967,8 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab,
 		case AT_SetStorage:		/* ALTER COLUMN SET STORAGE */
 			address = ATExecSetStorage(rel, cmd->name, cmd->def, lockmode);
 			break;
-		case AT_SetCompression:
-			address = ATExecSetCompression(tab, rel, cmd->name, cmd->def,
+		case AT_SetCompression: /* ALTER COLUMN SET COMPRESSION */
+			address = ATExecSetCompression(rel, cmd->name, cmd->def,
 										   lockmode);
 			break;
 		case AT_DropColumn:		/* DROP COLUMN */
@@ -6820,7 +6824,10 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	attribute.atttypmod = typmod;
 	attribute.attbyval = tform->typbyval;
 	attribute.attalign = tform->typalign;
-	attribute.attstorage = tform->typstorage;
+	if (colDef->storage_name)
+		attribute.attstorage = GetAttributeStorage(typeOid, colDef->storage_name);
+	else
+		attribute.attstorage = tform->typstorage;
 	attribute.attcompression = GetAttributeCompression(typeOid,
 													   colDef->compression);
 	attribute.attnotnull = colDef->is_not_null;
@@ -8263,33 +8270,12 @@ SetIndexStorageProperties(Relation rel, Relation attrelation,
 static ObjectAddress
 ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode)
 {
-	char	   *storagemode;
-	char		newstorage;
 	Relation	attrelation;
 	HeapTuple	tuple;
 	Form_pg_attribute attrtuple;
 	AttrNumber	attnum;
 	ObjectAddress address;
 
-	storagemode = strVal(newValue);
-
-	if (pg_strcasecmp(storagemode, "plain") == 0)
-		newstorage = TYPSTORAGE_PLAIN;
-	else if (pg_strcasecmp(storagemode, "external") == 0)
-		newstorage = TYPSTORAGE_EXTERNAL;
-	else if (pg_strcasecmp(storagemode, "extended") == 0)
-		newstorage = TYPSTORAGE_EXTENDED;
-	else if (pg_strcasecmp(storagemode, "main") == 0)
-		newstorage = TYPSTORAGE_MAIN;
-	else
-	{
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("invalid storage type \"%s\"",
-						storagemode)));
-		newstorage = 0;			/* keep compiler quiet */
-	}
-
 	attrelation = table_open(AttributeRelationId, RowExclusiveLock);
 
 	tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
@@ -8308,35 +8294,25 @@ ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE loc
 				 errmsg("cannot alter system column \"%s\"",
 						colName)));
 
-	/*
-	 * safety check: do not allow toasted storage modes unless column datatype
-	 * is TOAST-aware.
-	 */
-	if (newstorage == TYPSTORAGE_PLAIN || TypeIsToastable(attrtuple->atttypid))
-		attrtuple->attstorage = newstorage;
-	else
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("column data type %s can only have storage PLAIN",
-						format_type_be(attrtuple->atttypid))));
+	attrtuple->attstorage = GetAttributeStorage(attrtuple->atttypid, strVal(newValue));
 
 	CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
 
 	InvokeObjectPostAlterHook(RelationRelationId,
 							  RelationGetRelid(rel),
 							  attrtuple->attnum);
 
-	heap_freetuple(tuple);
-
 	/*
 	 * Apply the change to indexes as well (only for simple index columns,
 	 * matching behavior of index.c ConstructTupleDescriptor()).
 	 */
 	SetIndexStorageProperties(rel, attrelation, attnum,
-							  true, newstorage,
+							  true, attrtuple->attstorage,
 							  false, 0,
 							  lockmode);
 
+	heap_freetuple(tuple);
+
 	table_close(attrelation, RowExclusiveLock);
 
 	ObjectAddressSubSet(address, RelationRelationId,
@@ -16156,8 +16132,7 @@ ATExecGenericOptions(Relation rel, List *options)
  * Return value is the address of the modified column
  */
 static ObjectAddress
-ATExecSetCompression(AlteredTableInfo *tab,
-					 Relation rel,
+ATExecSetCompression(Relation rel,
 					 const char *column,
 					 Node *newValue,
 					 LOCKMODE lockmode)
@@ -19287,3 +19262,38 @@ GetAttributeCompression(Oid atttypid, char *compression)
 
 	return cmethod;
 }
+
+/*
+ * resolve column storage specification
+ */
+static char
+GetAttributeStorage(Oid atttypid, const char *storagemode)
+{
+	char		cstorage = 0;
+
+	if (pg_strcasecmp(storagemode, "plain") == 0)
+		cstorage = TYPSTORAGE_PLAIN;
+	else if (pg_strcasecmp(storagemode, "external") == 0)
+		cstorage = TYPSTORAGE_EXTERNAL;
+	else if (pg_strcasecmp(storagemode, "extended") == 0)
+		cstorage = TYPSTORAGE_EXTENDED;
+	else if (pg_strcasecmp(storagemode, "main") == 0)
+		cstorage = TYPSTORAGE_MAIN;
+	else
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid storage type \"%s\"",
+						storagemode)));
+
+	/*
+	 * safety check: do not allow toasted storage modes unless column datatype
+	 * is TOAST-aware.
+	 */
+	if (!(cstorage == TYPSTORAGE_PLAIN || TypeIsToastable(atttypid)))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("column data type %s can only have storage PLAIN",
+						format_type_be(atttypid))));
+
+	return cstorage;
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
@@ -595,7 +595,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 %type <node>	TableConstraint TableLikeClause
 %type <ival>	TableLikeOptionList TableLikeOption
-%type <str>		column_compression opt_column_compression
+%type <str>		column_compression opt_column_compression column_storage opt_column_storage
 %type <list>	ColQualList
 %type <node>	ColConstraint ColConstraintElem ConstraintAttr
 %type <ival>	key_match
@@ -2537,13 +2537,13 @@ alter_table_cmd:
 					$$ = (Node *) n;
 				}
 			/* ALTER TABLE <name> ALTER [COLUMN] <colname> SET STORAGE <storagemode> */
-			| ALTER opt_column ColId SET STORAGE ColId
+			| ALTER opt_column ColId SET column_storage
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
 
 					n->subtype = AT_SetStorage;
 					n->name = $3;
-					n->def = (Node *) makeString($6);
+					n->def = (Node *) makeString($5);
 					$$ = (Node *) n;
 				}
 			/* ALTER TABLE <name> ALTER [COLUMN] <colname> SET COMPRESSION <cm> */
@@ -3778,13 +3778,14 @@ TypedTableElement:
 			| TableConstraint					{ $$ = $1; }
 		;
 
-columnDef:	ColId Typename opt_column_compression create_generic_options ColQualList
+columnDef:	ColId Typename opt_column_storage opt_column_compression create_generic_options ColQualList
 				{
 					ColumnDef *n = makeNode(ColumnDef);
 
 					n->colname = $1;
 					n->typeName = $2;
-					n->compression = $3;
+					n->storage_name = $3;
+					n->compression = $4;
 					n->inhcount = 0;
 					n->is_local = true;
 					n->is_not_null = false;
@@ -3793,8 +3794,8 @@ columnDef:	ColId Typename opt_column_compression create_generic_options ColQualL
 					n->raw_default = NULL;
 					n->cooked_default = NULL;
 					n->collOid = InvalidOid;
-					n->fdwoptions = $4;
-					SplitColQualList($5, &n->constraints, &n->collClause,
+					n->fdwoptions = $5;
+					SplitColQualList($6, &n->constraints, &n->collClause,
 									 yyscanner);
 					n->location = @1;
 					$$ = (Node *) n;
@@ -3851,6 +3852,15 @@ opt_column_compression:
 			| /*EMPTY*/								{ $$ = NULL; }
 		;
 
+column_storage:
+			STORAGE ColId							{ $$ = $2; }
+		;
+
+opt_column_storage:
+			column_storage							{ $$ = $1; }
+			| /*EMPTY*/								{ $$ = NULL; }
+		;
+
 ColQualList:
 			ColQualList ColConstraint				{ $$ = lappend($1, $2); }
 			| /*EMPTY*/								{ $$ = NIL; }
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
@@ -695,6 +695,7 @@ typedef struct ColumnDef
 	bool		is_not_null;	/* NOT NULL constraint specified? */
 	bool		is_from_type;	/* column definition came from table type */
 	char		storage;		/* attstorage setting, or 0 for default */
+	char	   *storage_name;	/* attstorage setting name or NULL for default */
 	Node	   *raw_default;	/* default value (untransformed parse tree) */
 	Node	   *cooked_default; /* default value (transformed expr tree) */
 	char		identity;		/* attidentity setting */
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
@@ -2244,7 +2244,7 @@ alter table recur1 add column f2 int;
 alter table recur1 alter column f2 type recur2; -- fails
 ERROR:  composite type recur1 cannot be made a member of itself
 -- SET STORAGE may need to add a TOAST table
-create table test_storage (a text);
+create table test_storage (a text, c text storage plain);
 alter table test_storage alter a set storage plain;
 alter table test_storage add b int default 0; -- rewrite table to remove its TOAST table
 alter table test_storage alter a set storage extended; -- re-add TOAST table
@@ -2256,6 +2256,9 @@ where oid = 'test_storage'::regclass;
  t
 (1 row)
 
+-- check STORAGE correctness
+create table test_storage_failed (a text, b int storage extended);
+ERROR:  column data type integer can only have storage PLAIN
 -- test that SET STORAGE propagates to index correctly
 create index test_storage_idx on test_storage (b, a);
 alter table test_storage alter column a set storage external;
@@ -2264,6 +2267,7 @@ alter table test_storage alter column a set storage external;
  Column |  Type   | Collation | Nullable | Default | Storage  | Stats target | Description 
 --------+---------+-----------+----------+---------+----------+--------------+-------------
  a      | text    |           |          |         | external |              | 
+ c      | text    |           |          |         | plain    |              | 
  b      | integer |           |          | 0       | plain    |              | 
 Indexes:
     "test_storage_idx" btree (b, a)
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
@@ -1527,7 +1527,7 @@ alter table recur1 add column f2 int;
 alter table recur1 alter column f2 type recur2; -- fails
 
 -- SET STORAGE may need to add a TOAST table
-create table test_storage (a text);
+create table test_storage (a text, c text storage plain);
 alter table test_storage alter a set storage plain;
 alter table test_storage add b int default 0; -- rewrite table to remove its TOAST table
 alter table test_storage alter a set storage extended; -- re-add TOAST table
@@ -1536,6 +1536,9 @@ select reltoastrelid <> 0 as has_toast_table
 from pg_class
 where oid = 'test_storage'::regclass;
 
+-- check STORAGE correctness
+create table test_storage_failed (a text, b int storage extended);
+
 -- test that SET STORAGE propagates to index correctly
 create index test_storage_idx on test_storage (b, a);
 alter table test_storage alter column a set storage external;
