diff options
Diffstat (limited to 'src/backend/commands/tablecmds.c')
| -rw-r--r-- | src/backend/commands/tablecmds.c | 135 |
1 files changed, 68 insertions, 67 deletions
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index fbffaef1966..3556240c8ed 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -149,6 +149,7 @@ typedef enum AlterTablePass AT_PASS_ALTER_TYPE, /* ALTER COLUMN TYPE */ AT_PASS_ADD_COL, /* ADD COLUMN */ AT_PASS_SET_EXPRESSION, /* ALTER SET EXPRESSION */ + AT_PASS_OLD_COL_ATTRS, /* re-install attnotnull */ AT_PASS_OLD_INDEX, /* re-add existing indexes */ AT_PASS_OLD_CONSTR, /* re-add existing constraints */ /* We could support a RENAME COLUMN pass here, but not currently used */ @@ -7662,17 +7663,23 @@ ATExecDropNotNull(Relation rel, const char *colName, bool recurse, } /* - * Find the constraint that makes this column NOT NULL. + * Find the constraint that makes this column NOT NULL, and drop it if we + * see one. dropconstraint_internal() will do necessary consistency + * checking. If there isn't one, there are two possibilities: either the + * column is marked attnotnull because it's part of the primary key, and + * then we just throw an appropriate error; or it's a leftover marking + * that we can remove. However, before doing the latter, to avoid + * breaking consistency any further, prevent this if the column is part of + * the replica identity. */ conTup = findNotNullConstraint(RelationGetRelid(rel), colName); if (conTup == NULL) { Bitmapset *pkcols; + Bitmapset *ircols; /* - * There's no not-null constraint, so throw an error. If the column - * is in a primary key, we can throw a specific error. Otherwise, - * this is unexpected. + * If the column is in a primary key, throw a specific error message. */ pkcols = RelationGetIndexAttrBitmap(rel, INDEX_ATTR_BITMAP_PRIMARY_KEY); if (bms_is_member(attnum - FirstLowInvalidHeapAttributeNumber, @@ -7681,16 +7688,27 @@ ATExecDropNotNull(Relation rel, const char *colName, bool recurse, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column \"%s\" is in a primary key", colName)); - /* this shouldn't happen */ - elog(ERROR, "could not find not-null constraint on column \"%s\", relation \"%s\"", - colName, RelationGetRelationName(rel)); - } + /* Also throw an error if the column is in the replica identity */ + ircols = RelationGetIndexAttrBitmap(rel, INDEX_ATTR_BITMAP_IDENTITY_KEY); + if (bms_is_member(attnum - FirstLowInvalidHeapAttributeNumber, ircols)) + ereport(ERROR, + errcode(ERRCODE_INVALID_TABLE_DEFINITION), + errmsg("column \"%s\" is in index used as replica identity", + get_attname(RelationGetRelid(rel), attnum, false))); - readyRels = NIL; - dropconstraint_internal(rel, conTup, DROP_RESTRICT, recurse, false, - false, &readyRels, lockmode); + /* Otherwise, just remove the attnotnull marking and do nothing else. */ + attTup->attnotnull = false; + CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple); + } + else + { + /* The normal case: we have a pg_constraint row, remove it */ + readyRels = NIL; + dropconstraint_internal(rel, conTup, DROP_RESTRICT, recurse, false, + false, &readyRels, lockmode); - heap_freetuple(conTup); + heap_freetuple(conTup); + } InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attnum); @@ -12927,12 +12945,11 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha Form_pg_constraint con; ObjectAddress conobj; List *children; - ListCell *child; bool is_no_inherit_constraint = false; - bool dropping_pk = false; char *constrName; List *unconstrained_cols = NIL; - char *colname; + char *colname = NULL; + bool dropping_pk = false; if (list_member_oid(*readyRels, RelationGetRelid(rel))) return InvalidObjectAddress; @@ -12989,10 +13006,12 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha */ if (con->contype == CONSTRAINT_NOTNULL) { - AttrNumber colnum = extractNotNullColumn(constraintTup); + AttrNumber colnum; - if (colnum != InvalidAttrNumber) - unconstrained_cols = list_make1_int(colnum); + colnum = extractNotNullColumn(constraintTup); + unconstrained_cols = list_make1_int(colnum); + colname = NameStr(TupleDescAttr(RelationGetDescr(rel), + colnum - 1)->attname); } else if (con->contype == CONSTRAINT_PRIMARY) { @@ -13048,18 +13067,16 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha performDeletion(&conobj, behavior, 0); /* - * If this was a NOT NULL or the primary key, the constrained columns must - * have had pg_attribute.attnotnull set. See if we need to reset it, and - * do so. + * If this was a NOT NULL or the primary key, verify that we still have + * constraints to support GENERATED AS IDENTITY or the replica identity. */ - if (unconstrained_cols) + if (unconstrained_cols != NIL) { Relation attrel; Bitmapset *pkcols; Bitmapset *ircols; - ListCell *lc; - /* Make the above deletion visible */ + /* Make implicit attnotnull changes visible */ CommandCounterIncrement(); attrel = table_open(AttributeRelationId, RowExclusiveLock); @@ -13073,33 +13090,31 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha INDEX_ATTR_BITMAP_PRIMARY_KEY); ircols = RelationGetIndexAttrBitmap(rel, INDEX_ATTR_BITMAP_IDENTITY_KEY); - foreach(lc, unconstrained_cols) + foreach_int(attnum, unconstrained_cols) { - AttrNumber attnum = lfirst_int(lc); HeapTuple atttup; HeapTuple contup; Form_pg_attribute attForm; + char attidentity; /* - * Obtain pg_attribute tuple and verify conditions on it. We use - * a copy we can scribble on. + * Obtain pg_attribute tuple and verify conditions on it. */ - atttup = SearchSysCacheCopyAttNum(RelationGetRelid(rel), attnum); + atttup = SearchSysCacheAttNum(RelationGetRelid(rel), attnum); if (!HeapTupleIsValid(atttup)) elog(ERROR, "cache lookup failed for attribute %d of relation %u", attnum, RelationGetRelid(rel)); attForm = (Form_pg_attribute) GETSTRUCT(atttup); + attidentity = attForm->attidentity; + ReleaseSysCache(atttup); /* * Since the above deletion has been made visible, we can now * search for any remaining constraints on this column (or these * columns, in the case we're dropping a multicol primary key.) * Then, verify whether any further NOT NULL or primary key - * exists, and reset attnotnull if none. - * - * However, if this is a generated identity column, abort the - * whole thing with a specific error message, because the - * constraint is required in that case. + * exists: if none and this is a generated identity column or the + * replica identity, abort the whole thing. */ contup = findNotNullConstraintAttnum(RelationGetRelid(rel), attnum); if (contup || @@ -13111,7 +13126,7 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha * It's not valid to drop the not-null constraint for a GENERATED * AS IDENTITY column. */ - if (attForm->attidentity) + if (attidentity != '\0') ereport(ERROR, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" is an identity column", @@ -13123,18 +13138,11 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha * It's not valid to drop the not-null constraint for a column in * the replica identity index, either. (FULL is not affected.) */ - if (bms_is_member(lfirst_int(lc) - FirstLowInvalidHeapAttributeNumber, ircols)) + if (bms_is_member(attnum - FirstLowInvalidHeapAttributeNumber, ircols)) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column \"%s\" is in index used as replica identity", - get_attname(RelationGetRelid(rel), lfirst_int(lc), false))); - - /* Reset attnotnull */ - if (attForm->attnotnull) - { - attForm->attnotnull = false; - CatalogTupleUpdate(attrel, &atttup->t_self, atttup); - } + get_attname(RelationGetRelid(rel), attnum, false))); } table_close(attrel, RowExclusiveLock); } @@ -13173,16 +13181,8 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha errmsg("cannot remove constraint from only the partitioned table when partitions exist"), errhint("Do not specify the ONLY keyword."))); - /* For not-null constraints we recurse by column name */ - if (con->contype == CONSTRAINT_NOTNULL) - colname = NameStr(TupleDescAttr(RelationGetDescr(rel), - linitial_int(unconstrained_cols) - 1)->attname); - else - colname = NULL; /* keep compiler quiet */ - - foreach(child, children) + foreach_oid(childrelid, children) { - Oid childrelid = lfirst_oid(child); Relation childrel; HeapTuple tuple; Form_pg_constraint childcon; @@ -13195,8 +13195,8 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha CheckTableNotInUse(childrel, "ALTER TABLE"); /* - * We search for not-null constraint by column number, and other - * constraints by name. + * We search for not-null constraints by column name, and others by + * constraint name. */ if (con->contype == CONSTRAINT_NOTNULL) { @@ -13304,7 +13304,6 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha rel->rd_rel->relhassubclass) { List *colnames = NIL; - ListCell *lc; List *pkready = NIL; /* @@ -13317,15 +13316,14 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha * Find out the list of column names to process. Fortunately, we * already have the list of column numbers. */ - foreach(lc, unconstrained_cols) + foreach_int(attnum, unconstrained_cols) { colnames = lappend(colnames, get_attname(RelationGetRelid(rel), - lfirst_int(lc), false)); + attnum, false)); } - foreach(child, children) + foreach_oid(childrelid, children) { - Oid childrelid = lfirst_oid(child); Relation childrel; if (list_member_oid(pkready, childrelid)) @@ -13335,10 +13333,9 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha childrel = table_open(childrelid, NoLock); CheckTableNotInUse(childrel, "ALTER TABLE"); - foreach(lc, colnames) + foreach_ptr(char, colName, colnames) { HeapTuple contup; - char *colName = lfirst(lc); contup = findNotNullConstraint(childrelid, colName); if (contup == NULL) @@ -14677,12 +14674,16 @@ ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, char *cmd, else if (cmd->subtype == AT_SetAttNotNull) { /* - * The parser will create AT_AttSetNotNull subcommands for - * columns of PRIMARY KEY indexes/constraints, but we need - * not do anything with them here, because the columns' - * NOT NULL marks will already have been propagated into - * the new table definition. + * We see this subtype when a primary key is created + * internally, for example when it is replaced with a new + * constraint (say because one of the columns changes + * type); in this case we need to reinstate attnotnull, + * because it was removed because of the drop of the old + * PK. Schedule this subcommand to an upcoming AT pass. */ + cmd->subtype = AT_SetAttNotNull; + tab->subcmds[AT_PASS_OLD_COL_ATTRS] = + lappend(tab->subcmds[AT_PASS_OLD_COL_ATTRS], cmd); } else elog(ERROR, "unexpected statement subtype: %d", |