On Mon, Aug 01, 2005 at 04:02:14PM +0200, Renzo Kottmann wrote: > > Do other tables have foreign key references to t_node? If so, are > > there indexes on those tables' foreign key columns? How many records > > are in t_node and any tables that reference it? Do you keep the > > tables vacuumed and analyzed? > > Yes. I vacuumed and analyezed. There are several references (t_annotation > has two references to t_node): Here is the dicription of the tables.
The description for t_annotation shows the two references to t_node but no indexes on the referencing columns (ann_startnode_id and ann_endnode_id). When you delete records from t_node, the database has to check whether those deletions would cause a foreign key violation, so it has to search t_annotation for matching foreign keys. Without indexes on the referencing columns, the planner has to use a sequential scan instead of considering an index scan, so those searches are likely to be slow. Try creating indexes on the referencing columns (ann_startnode_id and ann_endnode_id) and on any other columns that refer to other tables. -- Michael Fuhr http://www.fuhr.org/~mfuhr/ ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
