Hi,
how about:
select sf.library_id, fio.clip_type , count(sf.sequence_id)
fromsequence_fragment sf, fragment_external_info fio
,(SELECT distinct sequence_id from sequence_alignment) sa
where sf.seq_frag_id = fio.sequence_frag_id
and sf.sequence_id = sa.sequence_id
group by s
On Wednesday 17 October 2007 20:23, Tom Lane wrote:
> Chris Kratz <[EMAIL PROTECTED]> writes:
> > On Wednesday 17 October 2007 14:49, Tom Lane wrote:
> >> Evidently it's not realizing that every row of par will have a join
> >> partner, but why not? I suppose a.activityid is unique, and in most
>
Hi Hekki-
When I turn seq_scan off for the new query:
explain
select sf.library_id, fio.clip_type , count(sf.sequence_id)
fromsequence_fragment sf, fragment_external_info fio
where sf.seq_frag_id = fio.sequence_frag_id
and sf.sequence_id IN
(SELECT sequence_id from sequence_alig
Hello Nis-
I did reset the defaults before running the explain.
Primary keys for the tables.
sequence_fragment.seq_frag_id
sequence.sequence_id
Candidate keys.
fragment_external_info.seq_frag_id (FK to sequence_fragment.seq_frag_id)
sequence_alignment.sequence_id (FK to sequence_fragment.se
John Major wrote:
> ~there are indexes on all of the fields being joined (but not on
> library_id or clip_type ). ~Everything has been re-analyzed post index
> creation
> ~I've tried "set enable_seqscan=off" and set (join_table_order or
> something) = 1
Seqscanning and sorting a table is generally
John Major skrev:
> I am trying to join three quite large tables, and the query is
> unbearably slow(meaning I can't get results in more than a day of
> processing).
> I've tried the basic optimizations I understand, and nothing has
> improved the execute speed any help with this would be great
I am trying to join three quite large tables, and the query is
unbearably slow(meaning I can't get results in more than a day of
processing).
I've tried the basic optimizations I understand, and nothing has
improved the execute speed any help with this would be greatly
appreciated
The th
Chris Kratz skrev:
> Hello Everyone,
>
> I'm struggling to get postgres to run a particular query quickly. It
> seems that very early on, the planner seems to mis-estimate the
> number of rows returned by a join which causes it to assume that
> there is only 1 row as it goes up the tree. It then
