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Allow ALTER TABLE name {OF type | NOT OF}.

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This syntax allows a standalone table to be made into a typed table,
or a typed table to be made standalone.  This is possibly a mildly
useful feature in its own right, but the real motivation for this
change is that we need it to make pg_upgrade work with typed tables.
This doesn't actually fix that problem, but it's necessary
infrastructure.

Noah Misch
This commit is contained in:
Robert Haas 2011-04-20 21:35:15 -04:00
parent 520bcd9c9b
commit 68739ba856
8 changed files with 376 additions and 38 deletions
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26
doc/src/sgml/ref/alter_table.sgml
View File

@ -63,6 +63,8 @@ ALTER TABLE <replaceable class="PARAMETER">name</replaceable>
RESET ( <replaceable class="PARAMETER">storage_parameter</replaceable> [, ... ] )
INHERIT <replaceable class="PARAMETER">parent_table</replaceable>
NO INHERIT <replaceable class="PARAMETER">parent_table</replaceable>
OF <replaceable class="PARAMETER">type_name</replaceable>
NOT OF
OWNER TO <replaceable class="PARAMETER">new_owner</replaceable>
SET TABLESPACE <replaceable class="PARAMETER">new_tablespace</replaceable>
@ -490,6 +492,30 @@ ALTER TABLE <replaceable class="PARAMETER">name</replaceable>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>OF <replaceable class="PARAMETER">type_name</replaceable></literal></term>
<listitem>
<para>
This form links the table to a composite type as though <command>CREATE
TABLE OF</> had formed it. The table's list of column names and types
must precisely match that of the composite type; the presence of
an <literal>oid</> system column is permitted to differ. The table must
not inherit from any other table. These restrictions ensure
that <command>CREATE TABLE OF</> would permit an equivalent table
definition.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>NOT OF</literal></term>
<listitem>
<para>
This form dissociates a typed table from its type.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>OWNER</literal></term>
<listitem>

273
src/backend/commands/tablecmds.c
View File

@ -81,6 +81,7 @@
#include "utils/snapmgr.h"
#include "utils/syscache.h"
#include "utils/tqual.h"
#include "utils/typcache.h"
/*
@ -357,6 +358,9 @@ static void ATExecEnableDisableRule(Relation rel, char *rulename,
static void ATPrepAddInherit(Relation child_rel);
static void ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode);
static void ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode);
static void drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid);
static void ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode);
static void ATExecDropOf(Relation rel, LOCKMODE lockmode);
static void ATExecGenericOptions(Relation rel, List *options);
static void copy_relation_data(SMgrRelation rel, SMgrRelation dst,
@ -2683,6 +2687,16 @@ AlterTableGetLockLevel(List *cmds)
cmd_lockmode = ShareUpdateExclusiveLock;
break;
/*
* These subcommands affect implicit row type conversion. They
* have affects similar to CREATE/DROP CAST on queries. We
* don't provide for invalidating parse trees as a result of
* such changes. Do avoid concurrent pg_class updates, though.
*/
case AT_AddOf:
case AT_DropOf:
cmd_lockmode = ShareUpdateExclusiveLock;
/*
* These subcommands affect general strategies for performance
* and maintenance, though don't change the semantic results
@ -2942,16 +2956,14 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
case AT_EnableAlwaysRule:
case AT_EnableReplicaRule:
case AT_DisableRule:
case AT_DropInherit: /* NO INHERIT */
case AT_AddOf: /* OF */
case AT_DropOf: /* NOT OF */
ATSimplePermissions(rel, ATT_TABLE);
/* These commands never recurse */
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_DropInherit: /* NO INHERIT */
ATSimplePermissions(rel, ATT_TABLE);
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_GenericOptions:
ATSimplePermissions(rel, ATT_FOREIGN_TABLE);
/* No command-specific prep needed */
@ -3211,6 +3223,12 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
case AT_DropInherit:
ATExecDropInherit(rel, (RangeVar *) cmd->def, lockmode);
break;
case AT_AddOf:
ATExecAddOf(rel, (TypeName *) cmd->def, lockmode);
break;
case AT_DropOf:
ATExecDropOf(rel, lockmode);
break;
case AT_GenericOptions:
ATExecGenericOptions(rel, (List *) cmd->def);
break;
@ -4045,6 +4063,42 @@ find_typed_table_dependencies(Oid typeOid, const char *typeName, DropBehavior be
}
/*
* check_of_type
*
* Check whether a type is suitable for CREATE TABLE OF/ALTER TABLE OF. If it
* isn't suitable, throw an error. Currently, we require that the type
* originated with CREATE TABLE AS. We could support any row type, but doing so
* would require handling a number of extra corner cases in the DDL commands.
*/
void
check_of_type(HeapTuple typetuple)
{
Form_pg_type typ = (Form_pg_type) GETSTRUCT(typetuple);
bool typeOk = false;
if (typ->typtype == TYPTYPE_COMPOSITE)
{
Relation typeRelation;
Assert(OidIsValid(typ->typrelid));
typeRelation = relation_open(typ->typrelid, AccessShareLock);
typeOk = (typeRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE);
/*
* Close the parent rel, but keep our AccessShareLock on it until xact
* commit. That will prevent someone else from deleting or ALTERing
* the type before the typed table creation/conversion commits.
*/
relation_close(typeRelation, NoLock);
}
if (!typeOk)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("type %s is not a composite type",
format_type_be(HeapTupleGetOid(typetuple)))));
}
/*
* ALTER TABLE ADD COLUMN
*
@ -8355,8 +8409,7 @@ ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
ScanKeyData key[3];
HeapTuple inheritsTuple,
attributeTuple,
constraintTuple,
depTuple;
constraintTuple;
List *connames;
bool found = false;
@ -8522,11 +8575,29 @@ ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
systable_endscan(scan);
heap_close(catalogRelation, RowExclusiveLock);
drop_parent_dependency(RelationGetRelid(rel),
RelationRelationId,
RelationGetRelid(parent_rel));
/* keep our lock on the parent relation until commit */
heap_close(parent_rel, NoLock);
}
/*
* Drop the dependency
*
* There's no convenient way to do this, so go trawling through pg_depend
* Drop the dependency created by StoreCatalogInheritance1 (CREATE TABLE
* INHERITS/ALTER TABLE INHERIT -- refclassid will be RelationRelationId) or
* heap_create_with_catalog (CREATE TABLE OF/ALTER TABLE OF -- refclassid will
* be TypeRelationId). There's no convenient way to do this, so go trawling
* through pg_depend.
*/
static void
drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid)
{
Relation catalogRelation;
SysScanDesc scan;
ScanKeyData key[3];
HeapTuple depTuple;
catalogRelation = heap_open(DependRelationId, RowExclusiveLock);
ScanKeyInit(&key[0],
@ -8536,7 +8607,7 @@ ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
ScanKeyInit(&key[1],
Anum_pg_depend_objid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
ObjectIdGetDatum(relid));
ScanKeyInit(&key[2],
Anum_pg_depend_objsubid,
BTEqualStrategyNumber, F_INT4EQ,
@ -8549,8 +8620,8 @@ ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
{
Form_pg_depend dep = (Form_pg_depend) GETSTRUCT(depTuple);
if (dep->refclassid == RelationRelationId &&
dep->refobjid == RelationGetRelid(parent_rel) &&
if (dep->refclassid == refclassid &&
dep->refobjid == refobjid &&
dep->refobjsubid == 0 &&
dep->deptype == DEPENDENCY_NORMAL)
simple_heap_delete(catalogRelation, &depTuple->t_self);
@ -8558,9 +8629,181 @@ ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
systable_endscan(scan);
heap_close(catalogRelation, RowExclusiveLock);
}
/* keep our lock on the parent relation until commit */
heap_close(parent_rel, NoLock);
/*
* ALTER TABLE OF
*
* Attach a table to a composite type, as though it had been created with CREATE
* TABLE OF. All attname, atttypid, atttypmod and attcollation must match. The
* subject table must not have inheritance parents. These restrictions ensure
* that you cannot create a configuration impossible with CREATE TABLE OF alone.
*/
static void
ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode)
{
Oid relid = RelationGetRelid(rel);
Type typetuple;
Form_pg_type typ;
Oid typeid;
Relation inheritsRelation,
relationRelation;
SysScanDesc scan;
ScanKeyData key;
AttrNumber table_attno,
type_attno;
TupleDesc typeTupleDesc,
tableTupleDesc;
ObjectAddress tableobj,
typeobj;
HeapTuple classtuple;
/* Validate the type. */
typetuple = typenameType(NULL, ofTypename, NULL);
check_of_type(typetuple);
typ = (Form_pg_type) GETSTRUCT(typetuple);
typeid = HeapTupleGetOid(typetuple);
/* Fail if the table has any inheritance parents. */
inheritsRelation = heap_open(InheritsRelationId, AccessShareLock);
ScanKeyInit(&key,
Anum_pg_inherits_inhrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(relid));
scan = systable_beginscan(inheritsRelation, InheritsRelidSeqnoIndexId,
true, SnapshotNow, 1, &key);
if (HeapTupleIsValid(systable_getnext(scan)))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("typed tables cannot inherit")));
systable_endscan(scan);
heap_close(inheritsRelation, AccessShareLock);
/*
* Check the tuple descriptors for compatibility. Unlike inheritance, we
* require that the order also match. However, attnotnull need not match.
* Also unlike inheritance, we do not require matching relhasoids.
*/
typeTupleDesc = lookup_rowtype_tupdesc(typeid, -1);
tableTupleDesc = RelationGetDescr(rel);
table_attno = 1;
for (type_attno = 1; type_attno <= typeTupleDesc->natts; type_attno++)
{
Form_pg_attribute type_attr,
table_attr;
const char *type_attname,
*table_attname;
/* Get the next non-dropped type attribute. */
type_attr = typeTupleDesc->attrs[type_attno - 1];
if (type_attr->attisdropped)
continue;
type_attname = NameStr(type_attr->attname);
/* Get the next non-dropped table attribute. */
do
{
if (table_attno > tableTupleDesc->natts)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table is missing column \"%s\"",
type_attname)));
table_attr = tableTupleDesc->attrs[table_attno++ - 1];
} while (table_attr->attisdropped);
table_attname = NameStr(table_attr->attname);
/* Compare name. */
if (strncmp(table_attname, type_attname, NAMEDATALEN) != 0)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table has column \"%s\" where type requires \"%s\"",
table_attname, type_attname)));
/* Compare type. */
if (table_attr->atttypid != type_attr->atttypid ||
table_attr->atttypmod != type_attr->atttypmod ||
table_attr->attcollation != type_attr->attcollation)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table \"%s\" has different type for column \"%s\"",
RelationGetRelationName(rel), type_attname)));
}
DecrTupleDescRefCount(typeTupleDesc);
/* Any remaining columns at the end of the table had better be dropped. */
for (; table_attno <= tableTupleDesc->natts; table_attno++)
{
Form_pg_attribute table_attr = tableTupleDesc->attrs[table_attno - 1];
if (!table_attr->attisdropped)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table has extra column \"%s\"",
NameStr(table_attr->attname))));
}
/* If the table was already typed, drop the existing dependency. */
if (rel->rd_rel->reloftype)
drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype);
/* Record a dependency on the new type. */
tableobj.classId = RelationRelationId;
tableobj.objectId = relid;
tableobj.objectSubId = 0;
typeobj.classId = TypeRelationId;
typeobj.objectId = typeid;
typeobj.objectSubId = 0;
recordDependencyOn(&tableobj, &typeobj, DEPENDENCY_NORMAL);
/* Update pg_class.reloftype */
relationRelation = heap_open(RelationRelationId, RowExclusiveLock);
classtuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(classtuple))
elog(ERROR, "cache lookup failed for relation %u", relid);
((Form_pg_class) GETSTRUCT(classtuple))->reloftype = typeid;
simple_heap_update(relationRelation, &classtuple->t_self, classtuple);
CatalogUpdateIndexes(relationRelation, classtuple);
heap_freetuple(classtuple);
heap_close(relationRelation, RowExclusiveLock);
ReleaseSysCache(typetuple);
}
/*
* ALTER TABLE NOT OF
*
* Detach a typed table from its originating type. Just clear reloftype and
* remove the dependency.
*/
static void
ATExecDropOf(Relation rel, LOCKMODE lockmode)
{
Oid relid = RelationGetRelid(rel);
Relation relationRelation;
HeapTuple tuple;
if (!OidIsValid(rel->rd_rel->reloftype))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a typed table",
RelationGetRelationName(rel))));
/*
* We don't bother to check ownership of the type --- ownership of the table
* is presumed enough rights. No lock required on the type, either.
*/
drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype);
/* Clear pg_class.reloftype */
relationRelation = heap_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", relid);
((Form_pg_class) GETSTRUCT(tuple))->reloftype = InvalidOid;
simple_heap_update(relationRelation, &tuple->t_self, tuple);
CatalogUpdateIndexes(relationRelation, tuple);
heap_freetuple(tuple);
heap_close(relationRelation, RowExclusiveLock);
}
/*

17
src/backend/parser/gram.y
View File

@ -1933,6 +1933,23 @@ alter_table_cmd:
n->def = (Node *) $3;
$$ = (Node *)n;
}
/* ALTER TABLE <name> OF <type_name> */
| OF any_name
{
AlterTableCmd *n = makeNode(AlterTableCmd);
TypeName *def = makeTypeNameFromNameList($2);
def->location = @2;
n->subtype = AT_AddOf;
n->def = (Node *) def;
$$ = (Node *)n;
}
/* ALTER TABLE <name> NOT OF */
| NOT OF
{
AlterTableCmd *n = makeNode(AlterTableCmd);
n->subtype = AT_DropOf;
$$ = (Node *)n;
}
/* ALTER TABLE <name> OWNER TO RoleId */
| OWNER TO RoleId
{

22
src/backend/parser/parse_utilcmd.c
View File

@ -825,35 +825,15 @@ transformOfType(CreateStmtContext *cxt, TypeName *ofTypename)
TupleDesc tupdesc;
int i;
Oid ofTypeId;
bool typeOk = false;
AssertArg(ofTypename);
tuple = typenameType(NULL, ofTypename, NULL);
check_of_type(tuple);
typ = (Form_pg_type) GETSTRUCT(tuple);
ofTypeId = HeapTupleGetOid(tuple);
ofTypename->typeOid = ofTypeId; /* cached for later */
if (typ->typtype == TYPTYPE_COMPOSITE)
{
Relation typeRelation;
Assert(OidIsValid(typ->typrelid));
typeRelation = relation_open(typ->typrelid, AccessShareLock);
typeOk = (typeRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE);
/*
* Close the parent rel, but keep our AccessShareLock on it until xact
* commit. That will prevent someone else from deleting or ALTERing
* the type before the typed table creation commits.
*/
relation_close(typeRelation, NoLock);
}
if (!typeOk)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("type %s is not a composite type",
format_type_be(ofTypeId))));
tupdesc = lookup_rowtype_tupdesc(ofTypeId, -1);
for (i = 0; i < tupdesc->natts; i++)
{

2
src/include/commands/tablecmds.h
View File

@ -56,6 +56,8 @@ extern void find_composite_type_dependencies(Oid typeOid,
Relation origRelation,
const char *origTypeName);
extern void check_of_type(HeapTuple typetuple);
extern AttrNumber *varattnos_map(TupleDesc olddesc, TupleDesc newdesc);
extern AttrNumber *varattnos_map_schema(TupleDesc old, List *schema);
extern void change_varattnos_of_a_node(Node *node, const AttrNumber *newattno);

2
src/include/nodes/parsenodes.h
View File

@ -1219,6 +1219,8 @@ typedef enum AlterTableType
AT_DisableRule, /* DISABLE RULE name */
AT_AddInherit, /* INHERIT parent */
AT_DropInherit, /* NO INHERIT parent */
AT_AddOf, /* OF <type_name> */
AT_DropOf, /* NOT OF */
AT_GenericOptions, /* OPTIONS (...) */
} AlterTableType;

38
src/test/regress/expected/alter_table.out
View File

@ -1942,3 +1942,41 @@ Typed table of type: test_type2
CREATE TYPE test_type_empty AS ();
DROP TYPE test_type_empty;
--
-- typed tables: OF / NOT OF
--
CREATE TYPE tt_t0 AS (z inet, x int, y numeric(8,2));
ALTER TYPE tt_t0 DROP ATTRIBUTE z;
CREATE TABLE tt0 (x int NOT NULL, y numeric(8,2)); -- OK
CREATE TABLE tt1 (x int, y bigint); -- wrong base type
CREATE TABLE tt2 (x int, y numeric(9,2)); -- wrong typmod
CREATE TABLE tt3 (y numeric(8,2), x int); -- wrong column order
CREATE TABLE tt4 (x int); -- too few columns
CREATE TABLE tt5 (x int, y numeric(8,2), z int); -- too few columns
CREATE TABLE tt6 () INHERITS (tt0); -- can't have a parent
CREATE TABLE tt7 (x int, q text, y numeric(8,2)) WITH OIDS;
ALTER TABLE tt7 DROP q; -- OK
ALTER TABLE tt0 OF tt_t0;
ALTER TABLE tt1 OF tt_t0;
ERROR: table "tt1" has different type for column "y"
ALTER TABLE tt2 OF tt_t0;
ERROR: table "tt2" has different type for column "y"
ALTER TABLE tt3 OF tt_t0;
ERROR: table has column "y" where type requires "x"
ALTER TABLE tt4 OF tt_t0;
ERROR: table is missing column "y"
ALTER TABLE tt5 OF tt_t0;
ERROR: table has extra column "z"
ALTER TABLE tt6 OF tt_t0;
ERROR: typed tables cannot inherit
ALTER TABLE tt7 OF tt_t0;
CREATE TYPE tt_t1 AS (x int, y numeric(8,2));
ALTER TABLE tt7 OF tt_t1; -- reassign an already-typed table
ALTER TABLE tt7 NOT OF;
\d tt7
Table "public.tt7"
Column | Type | Modifiers
--------+--------------+-----------
x | integer |
y | numeric(8,2) |

30
src/test/regress/sql/alter_table.sql
View File

@ -1369,3 +1369,33 @@ ALTER TYPE test_type2 RENAME ATTRIBUTE a TO aa CASCADE;
CREATE TYPE test_type_empty AS ();
DROP TYPE test_type_empty;
--
-- typed tables: OF / NOT OF
--
CREATE TYPE tt_t0 AS (z inet, x int, y numeric(8,2));
ALTER TYPE tt_t0 DROP ATTRIBUTE z;
CREATE TABLE tt0 (x int NOT NULL, y numeric(8,2)); -- OK
CREATE TABLE tt1 (x int, y bigint); -- wrong base type
CREATE TABLE tt2 (x int, y numeric(9,2)); -- wrong typmod
CREATE TABLE tt3 (y numeric(8,2), x int); -- wrong column order
CREATE TABLE tt4 (x int); -- too few columns
CREATE TABLE tt5 (x int, y numeric(8,2), z int); -- too few columns
CREATE TABLE tt6 () INHERITS (tt0); -- can't have a parent
CREATE TABLE tt7 (x int, q text, y numeric(8,2)) WITH OIDS;
ALTER TABLE tt7 DROP q; -- OK
ALTER TABLE tt0 OF tt_t0;
ALTER TABLE tt1 OF tt_t0;
ALTER TABLE tt2 OF tt_t0;
ALTER TABLE tt3 OF tt_t0;
ALTER TABLE tt4 OF tt_t0;
ALTER TABLE tt5 OF tt_t0;
ALTER TABLE tt6 OF tt_t0;
ALTER TABLE tt7 OF tt_t0;
CREATE TYPE tt_t1 AS (x int, y numeric(8,2));
ALTER TABLE tt7 OF tt_t1; -- reassign an already-typed table
ALTER TABLE tt7 NOT OF;
\d tt7