diff options
Diffstat (limited to 'src/backend/utils/cache/temprel.c')
| -rw-r--r-- | src/backend/utils/cache/temprel.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/src/backend/utils/cache/temprel.c b/src/backend/utils/cache/temprel.c index 0134b47a0f9..a0066f2eaff 100644 --- a/src/backend/utils/cache/temprel.c +++ b/src/backend/utils/cache/temprel.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/cache/Attic/temprel.c,v 1.31 2000/11/16 22:30:33 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/cache/Attic/temprel.c,v 1.32 2000/12/22 23:12:07 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -152,13 +152,19 @@ rename_temp_relation(const char *oldname, continue; /* ignore non-matching entries */ /* We are renaming a temp table --- is it OK to do so? */ - if (get_temp_rel_by_username(newname) != NULL) + if (is_temp_rel_name(newname)) elog(ERROR, "Cannot rename temp table \"%s\": temp table \"%s\" already exists", oldname, newname); /* * Create a new mapping entry and mark the old one deleted in this * xact. One of these entries will be deleted at xact end. + * + * NOTE: the new mapping entry is inserted into the list just after + * the old one. We could alternatively insert it before the old one, + * but that'd take more code. It does need to be in one spot or the + * other, to ensure that deletion of temp rels happens in the right + * order during remove_all_temp_relations(). */ oldcxt = MemoryContextSwitchTo(CacheMemoryContext); @@ -168,7 +174,7 @@ rename_temp_relation(const char *oldname, StrNCpy(NameStr(new_temp_rel->user_relname), newname, NAMEDATALEN); new_temp_rel->created_in_cur_xact = true; - temp_rels = lcons(new_temp_rel, temp_rels); + lnext(l) = lcons(new_temp_rel, lnext(l)); temp_rel->deleted_in_cur_xact = true; @@ -178,7 +184,7 @@ rename_temp_relation(const char *oldname, } /* Old name does not match any temp table name, what about new? */ - if (get_temp_rel_by_username(newname) != NULL) + if (is_temp_rel_name(newname)) elog(ERROR, "Cannot rename \"%s\" to \"%s\": a temp table by that name already exists", oldname, newname); @@ -205,7 +211,8 @@ remove_all_temp_relations(void) * Scan the list and delete all entries not already deleted. * We need not worry about list entries getting deleted from under us, * because remove_temp_rel_by_relid() doesn't remove entries, only - * mark them dead. + * mark them dead. Note that entries will be deleted in reverse order + * of creation --- that's critical for cases involving inheritance. */ foreach(l, temp_rels) { @@ -286,7 +293,8 @@ AtEOXact_temp_relations(bool isCommit) /* * Map user name to physical name --- returns NULL if no entry. * - * This is the normal way to test whether a name is a temp table name. + * This also supports testing whether a name is a temp table name; + * see is_temp_rel_name() macro. */ char * get_temp_rel_by_username(const char *user_relname) |