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Removed obsolete DROP_COLUMN_HACK stuff.
This commit is contained in:
Hiroshi Inoue
@@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.171 2002/04/01 22:36:09 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.172 2002/04/02 08:51:50 inoue Exp $
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*
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* NOTES
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* The PerformAddAttribute() code, like most of the relation
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@@ -1115,140 +1115,6 @@ AlterTableAlterColumnFlags(Oid myrelid,
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}
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#ifdef _DROP_COLUMN_HACK__
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/*
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* ALTER TABLE DROP COLUMN trial implementation
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*/
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/*
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* find a specified attribute in a node entry
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*/
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static bool
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find_attribute_walker(Node *node, int *attnump)
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{
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if (node == NULL)
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return false;
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if (IsA(node, Var))
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{
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Var *var = (Var *) node;
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if (var->varlevelsup == 0 && var->varno == 1 &&
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var->varattno == *attnump)
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return true;
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}
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return expression_tree_walker(node, find_attribute_walker,
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(void *) attnump);
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}
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static bool
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find_attribute_in_node(Node *node, int attnum)
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{
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return find_attribute_walker(node, &attnum);
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}
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/*
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* Remove/check references for the column
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*/
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static bool
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RemoveColumnReferences(Oid reloid, int attnum, bool checkonly, HeapTuple reltup)
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{
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Relation indexRelation,
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rcrel;
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ScanKeyData entry;
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HeapScanDesc scan;
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void *sysscan;
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HeapTuple htup,
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indexTuple;
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Form_pg_index index;
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Form_pg_class pgcform = (Form_pg_class) NULL;
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int i;
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bool checkok = true;
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if (!checkonly)
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pgcform = (Form_pg_class) GETSTRUCT(reltup);
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/*
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* Remove/check constraints here
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*/
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ScanKeyEntryInitialize(&entry, (bits16) 0x0,
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Anum_pg_relcheck_rcrelid,
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(RegProcedure) F_OIDEQ,
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ObjectIdGetDatum(reloid));
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rcrel = heap_openr(RelCheckRelationName, RowExclusiveLock);
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sysscan = systable_beginscan(rcrel, RelCheckIndex, true,
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SnapshotNow,
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1, &entry);
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while (HeapTupleIsValid(htup = systable_getnext(sysscan)))
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{
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Form_pg_relcheck relcheck;
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char *ccbin;
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Node *node;
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relcheck = (Form_pg_relcheck) GETSTRUCT(htup);
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ccbin = DatumGetCString(DirectFunctionCall1(textout,
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PointerGetDatum(&relcheck->rcbin)));
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node = stringToNode(ccbin);
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pfree(ccbin);
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if (find_attribute_in_node(node, attnum))
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{
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if (checkonly)
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{
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checkok = false;
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elog(ERROR, "target column is used in a constraint");
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}
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else
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{
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simple_heap_delete(rcrel, &htup->t_self);
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pgcform->relchecks--;
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}
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}
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}
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systable_endscan(sysscan);
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heap_close(rcrel, NoLock);
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/*
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* What to do with triggers/rules/views/procedues ?
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*/
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/*
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* Remove/check indexes
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*/
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indexRelation = heap_openr(IndexRelationName, RowExclusiveLock);
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ScanKeyEntryInitialize(&entry, 0, Anum_pg_index_indrelid, F_OIDEQ,
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ObjectIdGetDatum(reloid));
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scan = heap_beginscan(indexRelation, false, SnapshotNow, 1, &entry);
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while (HeapTupleIsValid(indexTuple = heap_getnext(scan, 0)))
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{
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index = (Form_pg_index) GETSTRUCT(indexTuple);
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for (i = 0; i < INDEX_MAX_KEYS; i++)
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{
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if (index->indkey[i] == InvalidAttrNumber)
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break;
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else if (index->indkey[i] == attnum)
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{
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if (checkonly)
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{
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checkok = false;
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elog(ERROR, "target column is used in an index");
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}
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else
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{
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index_drop(index->indexrelid);
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}
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break;
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}
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}
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}
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heap_endscan(scan);
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heap_close(indexRelation, NoLock);
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return checkok;
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}
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#endif /* _DROP_COLUMN_HACK__ */
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/*
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* ALTER TABLE DROP COLUMN
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@@ -1258,171 +1124,7 @@ AlterTableDropColumn(Oid myrelid,
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bool inh, const char *colName,
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int behavior)
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{
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#ifdef _DROP_COLUMN_HACK__
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Relation rel,
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attrdesc;
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HeapTuple reltup;
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HeapTupleData classtuple;
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Buffer buffer;
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Form_pg_attribute attribute;
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HeapTuple tup;
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Relation idescs[Num_pg_attr_indices];
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int attnum;
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bool hasindex;
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char dropColname[32];
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if (inh)
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elog(ERROR, "ALTER TABLE / DROP COLUMN with inherit option is not supported yet");
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/*
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* Grab an exclusive lock on the target table, which we will NOT
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* release until end of transaction.
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*/
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rel = heap_open(myrelid, AccessExclusiveLock);
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if (rel->rd_rel->relkind != RELKIND_RELATION)
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elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table",
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RelationGetRelationName(rel));
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if (!allowSystemTableMods
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&& IsSystemRelationName(RelationGetRelationName(rel)))
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elog(ERROR, "ALTER TABLE: relation \"%s\" is a system catalog",
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RelationGetRelationName(rel));
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/*
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* permissions checking. this would normally be done in utility.c,
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* but this particular routine is recursive.
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*
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* normally, only the owner of a class can change its schema.
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*/
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if (!pg_class_ownercheck(myrelid, GetUserId()))
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elog(ERROR, "ALTER TABLE: \"%s\": permission denied",
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RelationGetRelationName(rel));
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heap_close(rel, NoLock); /* close rel but keep lock! */
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/*
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* What to do when rel has inheritors ?
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*/
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if (length(find_all_inheritors(myrelid)) > 1)
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elog(ERROR, "ALTER TABLE: cannot drop a column on table that is inherited from");
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/*
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* lock the pg_class tuple for update
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*/
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rel = heap_openr(RelationRelationName, RowExclusiveLock);
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reltup = SearchSysCache(RELOID,
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ObjectIdGetDatum(myrelid),
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0, 0, 0);
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if (!HeapTupleIsValid(reltup))
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{
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Relation myrel;
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char *myrelname;
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myrel = heap_open(myrelid, AccessExclusiveLock);
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myrelname = pstrdup(RelationGetRelationName(myrel));
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heap_close(myrel, AccessExclusiveLock);
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elog(ERROR, "ALTER TABLE: relation \"%s\" not found",
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myrelname);
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}
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classtuple.t_self = reltup->t_self;
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ReleaseSysCache(reltup);
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switch (heap_mark4update(rel, &classtuple, &buffer))
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{
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case HeapTupleSelfUpdated:
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case HeapTupleMayBeUpdated:
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break;
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default:
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elog(ERROR, "couldn't lock pg_class tuple");
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}
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reltup = heap_copytuple(&classtuple);
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ReleaseBuffer(buffer);
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attrdesc = heap_openr(AttributeRelationName, RowExclusiveLock);
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/*
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* Get the target pg_attribute tuple and make a modifiable copy
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*/
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tup = SearchSysCacheCopy(ATTNAME,
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ObjectIdGetDatum(myrelid),
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PointerGetDatum(colName),
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0, 0);
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if (!HeapTupleIsValid(tup))
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{
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Relation myrel;
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char *myrelname;
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myrel = heap_open(myrelid, AccessExclusiveLock);
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myrelname = pstrdup(RelationGetRelationName(myrel));
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heap_close(myrel, AccessExclusiveLock);
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elog(ERROR, "ALTER TABLE: column name \"%s\" doesn't exist in table \"%s\"",
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colName, myrelname);
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}
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attribute = (Form_pg_attribute) GETSTRUCT(tup);
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attnum = attribute->attnum;
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if (attnum <= 0)
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elog(ERROR, "ALTER TABLE: column name \"%s\" was already dropped",
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colName);
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/*
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* Check constraints/indices etc here
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*/
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if (behavior != CASCADE)
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{
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if (!RemoveColumnReferences(myrelid, attnum, true, NULL))
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elog(ERROR, "the column is referenced");
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}
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/*
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* change the target pg_attribute tuple
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*/
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sprintf(dropColname, "*already Dropped*%d", attnum);
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namestrcpy(&(attribute->attname), dropColname);
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ATTRIBUTE_DROP_COLUMN(attribute);
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simple_heap_update(attrdesc, &tup->t_self, tup);
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hasindex = (!IsIgnoringSystemIndexes() && RelationGetForm(attrdesc)->relhasindex);
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if (hasindex)
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{
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CatalogOpenIndices(Num_pg_attr_indices, Name_pg_attr_indices, idescs);
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CatalogIndexInsert(idescs, Num_pg_attr_indices,
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attrdesc, tup);
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CatalogCloseIndices(Num_pg_attr_indices, idescs);
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}
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heap_close(attrdesc, NoLock);
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heap_freetuple(tup);
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/* delete comment for this attribute only */
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CreateComments(RelationGetRelid(rel), RelOid_pg_class,
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(int32) attnum, NULL);
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/* delete attrdef */
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drop_default(myrelid, attnum);
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/*
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* Remove objects which reference this column
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*/
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if (behavior == CASCADE)
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{
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Relation ridescs[Num_pg_class_indices];
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RemoveColumnReferences(myrelid, attnum, false, reltup);
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/* update pg_class tuple */
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simple_heap_update(rel, &reltup->t_self, reltup);
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CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, ridescs);
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CatalogIndexInsert(ridescs, Num_pg_class_indices, rel, reltup);
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CatalogCloseIndices(Num_pg_class_indices, ridescs);
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}
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heap_freetuple(reltup);
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heap_close(rel, NoLock);
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#else
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elog(ERROR, "ALTER TABLE / DROP COLUMN is not implemented");
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#endif /* _DROP_COLUMN_HACK__ */
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}
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