Subject Re: [firebird-support] Firebird 2.5.x slow queries problem
Author Tomasz Tyrakowski
On 2015-05-20 o 10:51, Sylvain Mazaudier smazaudi@...
[firebird-support] wrote:
> [...]
> Query select 1: SELECT ROW1 FROM TEST;
>
> Query select 2: SELECT ROW2 FROM TEST;
>
> R├ęsults in IBExpert monitor :
> Query select 1:1.5 sec
> Query select 2:5.3 sec
>
> [...]
>
> We don't understand why are the internal Firebird Queries very different and why does it takes 4 more time to execute on ROW2 ?

It's been a couple of days without any answer to this, so even though I
feel I'm not the most competent person, I'll give you my guess (I use
many different object abstractions over FB client library and experience
similar behaviour from time to time).
My point is, your question contains the answer. There's no such thing as
"internal Firebird queries". If you type a query A in your preferred
client application and instead a query B gets executed by the FB server,
it means your client application modifies your query (or executes
additional queries). In this case, I suppose IBExpert needs some extra
information about the tables and columns involved in your query, so it
queries system tables to get the metadata. Why it does with one query
and not with the other is the matter of its inner workings, of which I
have no knowledge.
Try to execute your queries with Fierbird's isql and compare the
results. If it behaves differently than IBExpert, the latter is to blame :).
Sorry for not being more specific, I don't use IBExpert and I'm not
familiar with its internals, but there's a lot of people on this list
who can give you better hints, just wait a while.

regards
Tomasz

--
__--==============================--__
__--== Tomasz Tyrakowski ==--__
__--== SOL-SYSTEM ==--__
__--== http://www.sol-system.pl ==--__
__--==============================--__