On 19/12/2013 21:36, Kevin Grittner wrote:
Marc Cousin <cousinmarc@xxxxxxxxx> wrote:
Then we insert missing paths. This is one of the plans that fail
insert into path (path)
select path from batch
where not exists
(select 1 from path where path.path=batch.path)
group by path;
I know you said you wanted to focus on a different query, but this
one can easily be optimized. Right now it is checking for an
existing row in path for each row in batch; and it only needs to
check once for each path. One way to write it would be:
insert into path (path)
select path from (select distinct path from batch) b
where not exists
(select 1 from path p where p.path = b.path);
Yeah, I know, that's why I said I didn't want to focus on this one… we
already do this optimization :)
Thanks anyway :)
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