diff options
Diffstat (limited to 'src/backend/catalog/heap.c')
| -rw-r--r-- | src/backend/catalog/heap.c | 162 |
1 files changed, 153 insertions, 9 deletions
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c index 0f3044b9a6..bd0a8668d0 100644 --- a/src/backend/catalog/heap.c +++ b/src/backend/catalog/heap.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.103 1999/10/07 05:48:03 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.104 1999/10/15 01:49:39 momjian Exp $ * * * INTERFACE ROUTINES @@ -38,6 +38,7 @@ #include "catalog/index.h" #include "catalog/indexing.h" #include "catalog/pg_attrdef.h" +#include "catalog/pg_description.h" #include "catalog/pg_index.h" #include "catalog/pg_inherits.h" #include "catalog/pg_ipl.h" @@ -67,6 +68,7 @@ static void AddNewRelationTuple(Relation pg_class_desc, Relation new_rel_desc, Oid new_rel_oid, unsigned natts, char relkind, char *temp_relname); static void AddToNoNameRelList(Relation r); + static void DeleteAttributeTuples(Relation rel); static void DeleteRelationTuple(Relation rel); static void DeleteTypeTuple(Relation rel); @@ -861,10 +863,11 @@ heap_create_with_catalog(char *relname, * 2) remove inheritance information * 3) remove indexes * 4) remove pg_class tuple - * 5) remove pg_attribute tuples - * 6) remove pg_type tuples - * 7) RemoveConstraints () - * 8) unlink relation + * 5) remove pg_attribute tuples and related descriptions + * 6) remove pg_description tuples + * 7) remove pg_type tuples + * 8) RemoveConstraints () + * 9) unlink relation * * old comments * Except for vital relations, removes relation from @@ -1269,18 +1272,152 @@ DeleteAttributeTuples(Relation rel) attnum++) { if (HeapTupleIsValid(tup = SearchSysCacheTupleCopy(ATTNUM, - ObjectIdGetDatum(RelationGetRelid(rel)), - Int16GetDatum(attnum), + ObjectIdGetDatum(RelationGetRelid(rel)), + Int16GetDatum(attnum), 0, 0))) { - heap_delete(pg_attribute_desc, &tup->t_self, NULL); - pfree(tup); + DeleteComments(tup->t_data->t_oid); + heap_delete(pg_attribute_desc, &tup->t_self, NULL); + pfree(tup); } } heap_close(pg_attribute_desc, RowExclusiveLock); } +/* ---------------------------------------------------------- + * CreateComments + * + * This routine is handed the oid and the command associated + * with that id and will insert, update, or delete (if the + * comment is an empty string or a NULL pointer) the associated + * comment from the system cataloge, pg_description. + * + * ---------------------------------------------------------- + */ + +void +CreateComments(Oid oid, char *comment) +{ + + Relation description; + TupleDesc tupDesc; + HeapScanDesc scan; + ScanKeyData entry; + HeapTuple desctuple, searchtuple; + Datum values[Natts_pg_description]; + char nulls[Natts_pg_description]; + char replaces[Natts_pg_description]; + bool modified = false; + int i; + + /*** Open pg_description, form a new tuple, if necessary ***/ + + description = heap_openr(DescriptionRelationName, RowExclusiveLock); + tupDesc = description->rd_att; + if ((comment != NULL) && (strlen(comment) > 0)) { + for (i = 0; i < Natts_pg_description; i++) { + nulls[i] = ' '; + replaces[i] = 'r'; + values[i] = (Datum) NULL; + } + i = 0; + values[i++] = ObjectIdGetDatum(oid); + values[i++] = (Datum) fmgr(F_TEXTIN, comment); + } + + /*** Now, open pg_description and attempt to find the old tuple ***/ + + ScanKeyEntryInitialize(&entry, 0x0, Anum_pg_description_objoid, F_OIDEQ, + ObjectIdGetDatum(oid)); + scan = heap_beginscan(description, false, SnapshotNow, 1, &entry); + searchtuple = heap_getnext(scan, 0); + + /*** If a previous tuple exists, either delete it or prepare a replacement ***/ + + if (HeapTupleIsValid(searchtuple)) { + + /*** If the comment is blank, call heap_delete, else heap_replace ***/ + + if ((comment == NULL) || (strlen(comment) == 0)) { + heap_delete(description, &searchtuple->t_self, NULL); + } else { + desctuple = heap_modifytuple(searchtuple, description, values, nulls, replaces); + setheapoverride(true); + heap_replace(description, &searchtuple->t_self, desctuple, NULL); + setheapoverride(false); + modified = TRUE; + } + + } else { + desctuple = heap_formtuple(tupDesc, values, nulls); + heap_insert(description, desctuple); + modified = TRUE; + } + + /*** Complete the scan, update indices, if necessary ***/ + + heap_endscan(scan); + + if (modified) { + if (RelationGetForm(description)->relhasindex) { + Relation idescs[Num_pg_description_indices]; + + CatalogOpenIndices(Num_pg_description_indices, Name_pg_description_indices, idescs); + CatalogIndexInsert(idescs, Num_pg_description_indices, description, desctuple); + CatalogCloseIndices(Num_pg_description_indices, idescs); + } + pfree(desctuple); + + } + + heap_close(description, RowExclusiveLock); + +} + +/* -------------------------------- + * DeleteComments + * + * This routine is used to purge any comments + * associated with the Oid handed to this routine, + * regardless of the actual object type. It is + * called, for example, when a relation is destroyed. + * -------------------------------- + */ + +void +DeleteComments(Oid oid) +{ + + Relation description; + TupleDesc tupDesc; + ScanKeyData entry; + HeapScanDesc scan; + HeapTuple searchtuple; + + description = heap_openr(DescriptionRelationName, RowExclusiveLock); + tupDesc = description->rd_att; + + /*** Now, open pg_description and attempt to find the old tuple ***/ + + ScanKeyEntryInitialize(&entry, 0x0, Anum_pg_description_objoid, F_OIDEQ, + ObjectIdGetDatum(oid)); + scan = heap_beginscan(description, false, SnapshotNow, 1, &entry); + searchtuple = heap_getnext(scan, 0); + + /*** If a previous tuple exists, delete it ***/ + + if (HeapTupleIsValid(searchtuple)) { + heap_delete(description, &searchtuple->t_self, NULL); + } + + /*** Complete the scan, update indices, if necessary ***/ + + heap_endscan(scan); + heap_close(description, RowExclusiveLock); + +} + /* -------------------------------- * DeleteTypeTuple * @@ -1471,6 +1608,13 @@ heap_destroy_with_catalog(char *relname) */ DeleteAttributeTuples(rel); + /* ---------------- + * delete comments + * ---------------- + */ + + DeleteComments(RelationGetRelid(rel)); + if (istemp) remove_temp_relation(rid); |