On Thu, 21 Apr 2005, Enrico Weigelt wrote: > I'm doing a simple lookup in a small table by an unique id, and I'm > wondering, why explains tells me seqscan is used instead the key. > > The table looks like: > > id bigint primary key, > a varchar, > b varchar, > c varchar > > and I'm quering: select * from foo where id = 2; > > I've got only 15 records in this table, but I wanna have it as > fast as possible since its used (as a map between IDs and names) > for larger queries.
Two general things: For 15 records, an index scan may not be faster. For simple tests you can play with enable_seqscan to see, but for more complicated queries it's a little harder to tell. If you're using a version earlier than 8.0, you'll need to quote or cast the value you're searching for due to problems with cross-type comparisons (the 2 would be treated as int4). ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
