Subject | Re: [firebird-support] Migrating from Super Classic FB 2.5.2 to SuperServer FB 3.0 could have a problems |
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Author | |
Post date | 2016-05-01T08:43:40Z |
Hi all,
Just migrating from SC FB 2.5.2 to SS FB 3.0 (both in Win
x64), i found a few problems :
1) Query that runs about 2-3 secs in SC FB
2.5.2, runs minutes in SS FB 3.0
Query is something like this :
Select
a.col1,b.col1 from tbl1 a, tbl2 b where a.id = b.id and b.id in (select c.id
from tbl3 c)
SS FB 3.0 uses different query plan that not use indices, no
wonder it was so slow.
Changed query to :
Select a.col1,b.col1 from
tbl1 a, tbl2 b, tbl3 c where a.id = b.id and b.id= c.id
Runs around 1-2
secs in SS FB 3.0, but runs minutes in SC FB 2.5.2
2) Since in FB 3.0, SS
is able to use SMP & shared Db Cache, I tried to set Db Cache to 512 MB via
gfix. It was without error.
First connection is OK & I could saw
that the actual Db cache size is around 300 MB. But after connection closed
& tried to connect again, FB raised an error, something like connection
lost.
Changed Db Cache to 256 MB fixed th e problem. I think, for modern
computer, 256 MB is too small.
Regards,
Anto.