database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-13 07:41:39 +03:00
Code Activity

Add ALTER TABLE ... ALTER CONSTRAINT ... SET [NO] INHERIT

Browse Source 
This allows to redefine an existing non-inheritable constraint to be
inheritable, which allows to straighten up situations with NO INHERIT
constraints so that thay can become normal constraints without having to
re-verify existing data.  For existing inheritance children this may
require creating additional constraints, if they don't exist already.

It also allows to do the opposite, if only for symmetry.

Author: Suraj Kharage <suraj.kharage@enterprisedb.com>
Reviewed-by: jian he <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CAF1DzPVfOW6Kk=7SSh7LbneQDJWh=PbJrEC_Wkzc24tHOyQWGg@mail.gmail.com
This commit is contained in:
Álvaro Herrera
2025-03-05 13:50:22 +01:00
parent f4694e0f35
commit f4e53e10b6
6 changed files with 359 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

115
src/backend/commands/tablecmds.c
View File

@ -389,9 +389,10 @@ static void AlterIndexNamespaces(Relation classRel, Relation rel,
static void AlterSeqNamespaces(Relation classRel, Relation rel,
Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved,
LOCKMODE lockmode);
static ObjectAddress ATExecAlterConstraint(Relation rel, ATAlterConstraint *cmdcon,
static ObjectAddress ATExecAlterConstraint(List **wqueue, Relation rel,
ATAlterConstraint *cmdcon,
bool recurse, LOCKMODE lockmode);
static bool ATExecAlterConstraintInternal(ATAlterConstraint *cmdcon, Relation conrel,
static bool ATExecAlterConstraintInternal(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel,
Relation tgrel, Relation rel, HeapTuple contuple,
bool recurse, List **otherrelids, LOCKMODE lockmode);
static void AlterConstrTriggerDeferrability(Oid conoid, Relation tgrel, Relation rel,
@ -5437,8 +5438,8 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab,
lockmode);
break;
case AT_AlterConstraint: /* ALTER CONSTRAINT */
address = ATExecAlterConstraint(rel, castNode(ATAlterConstraint,
cmd->def),
address = ATExecAlterConstraint(wqueue, rel,
castNode(ATAlterConstraint, cmd->def),
cmd->recurse, lockmode);
break;
case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */
@ -11813,14 +11814,14 @@ GetForeignKeyCheckTriggers(Relation trigrel,
*
* Update the attributes of a constraint.
*
* Currently only works for Foreign Key constraints.
* Currently only works for Foreign Key and not null constraints.
*
* If the constraint is modified, returns its address; otherwise, return
* InvalidObjectAddress.
*/
static ObjectAddress
ATExecAlterConstraint(Relation rel, ATAlterConstraint *cmdcon, bool recurse,
LOCKMODE lockmode)
ATExecAlterConstraint(List **wqueue, Relation rel, ATAlterConstraint *cmdcon,
bool recurse, LOCKMODE lockmode)
{
Relation conrel;
Relation tgrel;
@ -11871,11 +11872,26 @@ ATExecAlterConstraint(Relation rel, ATAlterConstraint *cmdcon, bool recurse,
cmdcon->conname, RelationGetRelationName(rel))));
currcon = (Form_pg_constraint) GETSTRUCT(contuple);
if (currcon->contype != CONSTRAINT_FOREIGN)
if (cmdcon->alterDeferrability && currcon->contype != CONSTRAINT_FOREIGN)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key constraint",
cmdcon->conname, RelationGetRelationName(rel))));
if (cmdcon->alterInheritability &&
currcon->contype != CONSTRAINT_NOTNULL)
ereport(ERROR,
errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("constraint \"%s\" of relation \"%s\" is not a not-null constraint",
cmdcon->conname, RelationGetRelationName(rel)));
/* Refuse to modify inheritability of inherited constraints */
if (cmdcon->alterInheritability &&
cmdcon->noinherit && currcon->coninhcount > 0)
ereport(ERROR,
errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot alter inherited constraint \"%s\" on relation \"%s\"",
NameStr(currcon->conname),
RelationGetRelationName(rel)));
/*
* If it's not the topmost constraint, raise an error.
@ -11926,8 +11942,8 @@ ATExecAlterConstraint(Relation rel, ATAlterConstraint *cmdcon, bool recurse,
/*
* Do the actual catalog work, and recurse if necessary.
*/
if (ATExecAlterConstraintInternal(cmdcon, conrel, tgrel, rel, contuple,
recurse, &otherrelids, lockmode))
if (ATExecAlterConstraintInternal(wqueue, cmdcon, conrel, tgrel, rel,
contuple, recurse, &otherrelids, lockmode))
ObjectAddressSet(address, ConstraintRelationId, currcon->oid);
/*
@ -11958,9 +11974,10 @@ ATExecAlterConstraint(Relation rel, ATAlterConstraint *cmdcon, bool recurse,
* but existing releases don't do that.)
*/
static bool
ATExecAlterConstraintInternal(ATAlterConstraint *cmdcon, Relation conrel,
Relation tgrel, Relation rel, HeapTuple contuple,
bool recurse, List **otherrelids, LOCKMODE lockmode)
ATExecAlterConstraintInternal(List **wqueue, ATAlterConstraint *cmdcon,
Relation conrel, Relation tgrel, Relation rel,
HeapTuple contuple, bool recurse,
List **otherrelids, LOCKMODE lockmode)
{
Form_pg_constraint currcon;
Oid refrelid = InvalidOid;
@ -12040,14 +12057,82 @@ ATExecAlterConstraintInternal(ATAlterConstraint *cmdcon, Relation conrel,
Relation childrel;
childrel = table_open(childcon->conrelid, lockmode);
ATExecAlterConstraintInternal(cmdcon, conrel, tgrel, childrel, childtup,
recurse, otherrelids, lockmode);
ATExecAlterConstraintInternal(wqueue, cmdcon, conrel, tgrel, childrel,
childtup, recurse, otherrelids, lockmode);
table_close(childrel, NoLock);
}
systable_endscan(pscan);
}
/*
* Update the catalog for inheritability. No work if the constraint is
* already in the requested state.
*/
if (cmdcon->alterInheritability &&
(cmdcon->noinherit != currcon->connoinherit))
{
AttrNumber colNum;
char *colName;
List *children;
HeapTuple copyTuple;
Form_pg_constraint copy_con;
/* The current implementation only works for NOT NULL constraints */
Assert(currcon->contype == CONSTRAINT_NOTNULL);
copyTuple = heap_copytuple(contuple);
copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
copy_con->connoinherit = cmdcon->noinherit;
CatalogTupleUpdate(conrel, &copyTuple->t_self, copyTuple);
CommandCounterIncrement();
heap_freetuple(copyTuple);
changed = true;
/* Fetch the column number and name */
colNum = extractNotNullColumn(contuple);
colName = get_attname(currcon->conrelid, colNum, false);
/*
* Propagate the change to children. For SET NO INHERIT, we don't
* recursively affect children, just the immediate level.
*/
children = find_inheritance_children(RelationGetRelid(rel),
lockmode);
foreach_oid(childoid, children)
{
ObjectAddress addr;
if (cmdcon->noinherit)
{
HeapTuple childtup;
Form_pg_constraint childcon;
childtup = findNotNullConstraint(childoid, colName);
if (!childtup)
elog(ERROR, "cache lookup failed for not-null constraint on column \"%s\" of relation %u",
colName, childoid);
childcon = (Form_pg_constraint) GETSTRUCT(childtup);
Assert(childcon->coninhcount > 0);
childcon->coninhcount--;
childcon->conislocal = true;
CatalogTupleUpdate(conrel, &childtup->t_self, childtup);
heap_freetuple(childtup);
}
else
{
Relation childrel = table_open(childoid, NoLock);
addr = ATExecSetNotNull(wqueue, childrel, NameStr(currcon->conname),
colName, true, true, lockmode);
if (OidIsValid(addr.objectId))
CommandCounterIncrement();
table_close(childrel, NoLock);
}
}
}
return changed;
}