diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index cb2c5e1..83dc6df 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -10508,9 +10508,6 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, SysScanDesc scan; HeapTuple depTup; ObjectAddress address; - ListCell *lc; - ListCell *prev; - ListCell *next; /* * Clear all the missing values if we're rewriting the table, since this @@ -10603,11 +10600,6 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, * performed all the individual ALTER TYPE operations. We have to save * the info before executing ALTER TYPE, though, else the deparser will * get confused. - * - * There could be multiple entries for the same object, so we must check - * to ensure we process each one only once. Note: we assume that an index - * that implements a constraint will not show a direct dependency on the - * column. */ depRel = table_open(DependRelationId, RowExclusiveLock); @@ -10650,19 +10642,21 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, relKind == RELKIND_PARTITIONED_INDEX) { /* - * Indexes that are directly dependent on the table - * might be regular indexes or constraint indexes. - * Constraint indexes typically have only indirect - * dependencies; but there are exceptions, notably - * partial exclusion constraints. Hence we must check - * whether the index depends on any constraint that's - * due to be rebuilt, which we'll do below after we've - * found all such constraints. + * This de-duplication check is critical for two + * independent reasons: we mustn't try to create the + * same index twice, and if an index depends on more + * than one column whose type is to be altered, we + * must capture its definition string before applying + * any of the column type changes. */ Assert(foundObject.objectSubId == 0); - tab->changedIndexOids = - list_append_unique_oid(tab->changedIndexOids, - foundObject.objectId); + if (!list_member_oid(tab->changedIndexOids, foundObject.objectId)) + { + tab->changedIndexOids = lappend_oid(tab->changedIndexOids, + foundObject.objectId); + tab->changedIndexDefs = lappend(tab->changedIndexDefs, + pg_get_indexdef_string(foundObject.objectId)); + } } else if (relKind == RELKIND_SEQUENCE) { @@ -10697,6 +10691,12 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, } case OCLASS_CONSTRAINT: + + /* + * As with indexes, de-duplication is critical, and it's + * needed because the same constraint could depend on multiple + * target columns. + */ Assert(foundObject.objectSubId == 0); if (!list_member_oid(tab->changedConstraintOids, foundObject.objectId)) @@ -10829,41 +10829,6 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, systable_endscan(scan); /* - * Check the collected index OIDs to see which ones belong to the - * constraint(s) of the table, and drop those from the list of indexes - * that we need to process; rebuilding the constraints will handle them. - */ - prev = NULL; - for (lc = list_head(tab->changedIndexOids); lc; lc = next) - { - Oid indexoid = lfirst_oid(lc); - Oid conoid; - - next = lnext(lc); - - conoid = get_index_constraint(indexoid); - if (OidIsValid(conoid) && - list_member_oid(tab->changedConstraintOids, conoid)) - tab->changedIndexOids = list_delete_cell(tab->changedIndexOids, - lc, prev); - else - prev = lc; - } - - /* - * Now collect the definitions of the indexes that must be rebuilt. (We - * could merge this into the previous loop, but it'd be more complicated - * for little gain.) - */ - foreach(lc, tab->changedIndexOids) - { - Oid indexoid = lfirst_oid(lc); - - tab->changedIndexDefs = lappend(tab->changedIndexDefs, - pg_get_indexdef_string(indexoid)); - } - - /* * Now scan for dependencies of this column on other things. The only * thing we should find is the dependency on the column datatype, which we * want to remove, possibly a collation dependency, and dependencies on @@ -11242,8 +11207,25 @@ ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode) def_item, tab->changedIndexDefs) { Oid oldId = lfirst_oid(oid_item); + Oid conoid; Oid relid; + /* + * We must check each index to see if it belongs to a constraint that + * we already processed above. Typically this check does not fire + * because constraint indexes normally have only dependencies on their + * constraint, and thus would not have been found by the dependency + * scan in ATExecAlterColumnType. But it's possible for such an index + * to also have direct dependencies on the table, for example with a + * partial exclusion constraint. In that case we'd have list entries + * for both the index and the constraint, and we must disregard the + * one for the index. + */ + conoid = get_index_constraint(oldId); + if (OidIsValid(conoid) && + list_member_oid(tab->changedConstraintOids, conoid)) + continue; + relid = IndexGetRelation(oldId, false); ATPostAlterTypeParse(oldId, relid, InvalidOid, (char *) lfirst(def_item), diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out index c845a16..01ba41c 100644 --- a/src/test/regress/expected/alter_table.out +++ b/src/test/regress/expected/alter_table.out @@ -1906,6 +1906,10 @@ alter table anothertab add exclude using btree (f3 with =); alter table anothertab add exclude using btree (f4 with =) where (f4 is not null); +alter table anothertab + add unique(f3,f4); +create index on anothertab(f2,f3); +create unique index on anothertab(f4); \d anothertab Table "public.anothertab" Column | Type | Collation | Nullable | Default @@ -1917,6 +1921,9 @@ alter table anothertab Indexes: "anothertab_pkey" PRIMARY KEY, btree (f1) "anothertab_f2_key" UNIQUE CONSTRAINT, btree (f2) + "anothertab_f3_f4_key" UNIQUE CONSTRAINT, btree (f3, f4) + "anothertab_f4_idx" UNIQUE, btree (f4) + "anothertab_f2_f3_idx" btree (f2, f3) "anothertab_f3_excl" EXCLUDE USING btree (f3 WITH =) "anothertab_f4_excl" EXCLUDE USING btree (f4 WITH =) WHERE (f4 IS NOT NULL) @@ -1936,6 +1943,9 @@ alter table anothertab Indexes: "anothertab_pkey" PRIMARY KEY, btree (f1) "anothertab_f2_key" UNIQUE CONSTRAINT, btree (f2) + "anothertab_f3_f4_key" UNIQUE CONSTRAINT, btree (f3, f4) + "anothertab_f4_idx" UNIQUE, btree (f4) + "anothertab_f2_f3_idx" btree (f2, f3) "anothertab_f3_excl" EXCLUDE USING btree (f3 WITH =) "anothertab_f4_excl" EXCLUDE USING btree (f4 WITH =) WHERE (f4 IS NOT NULL) diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql index 8c8b627..95fa1ce 100644 --- a/src/test/regress/sql/alter_table.sql +++ b/src/test/regress/sql/alter_table.sql @@ -1323,6 +1323,10 @@ alter table anothertab add exclude using btree (f3 with =); alter table anothertab add exclude using btree (f4 with =) where (f4 is not null); +alter table anothertab + add unique(f3,f4); +create index on anothertab(f2,f3); +create unique index on anothertab(f4); \d anothertab alter table anothertab alter column f1 type bigint;