On Saturday March 25 2006 9:49 pm, Ed L. wrote:
> On Saturday March 25 2006 9:36 pm, Ed L. wrote:
> > I have a performance riddle, hoping someone can point me in
> > a helpful direction. We have a pg 8.1.2 cluster using
> > Apache::Sessions and experiencing simple UPDATEs taking
> > sometimes 30+ seconds to do a very simply update, no foreign
> > keys, no triggers:
> >
> > Table "public.sessions"
> > Column | Type | Modifiers
> > -----------+---------------+-----------
> > id | character(32) | not null
> > a_session | text |
> > Indexes:
> > "sessions_pkey" PRIMARY KEY, btree (id)
>
> The table has 6800 rows over 18000 pages, and is getting a
> minimum of many tens of thousands of updates per day with
> queries like this:
>
> UPDATE sessions SET a_session = ? WHERE id = ?
Sorry, it's getting late. Yes, the table has been analyzed and
explain shows an index scan is occurring.
Ed
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
