Subject AW: [firebird-support] Optimize query for date ranges
Author Parzival
Hi,

the execution is currently not the problem, because the number of records is
too small.

I have the impression that the first query looks for DATUM >= x and the
second one for DATUM <= y and finally delivers the number of records that is
included in both result sets.

My main interesst is to understand if I can improve my query or have to
accept it. In the second case I will try to run as many queries as possible
without dateranges.

Niko

-----Urspr├╝ngliche Nachricht-----
Von: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com]
Gesendet: Montag, 12. Oktober 2015 17:31
An: firebird-support@yahoogroups.com
Betreff: Re: [firebird-support] Optimize query for date ranges

Niko,

> Hello all,
>
> i am running a simple query where the result contains 3 records. The
> query should provide all records in a specific week.
>
> SELECT * FROM ARBEITSEINTEILUNG AS a where a.baustelle = '12345' AND
> WOCHE = '2015-41';
>
> Some times I dont have a week but two dates:
>
> In this case ┬ľ the very same number of records = 3 is the result set I
> see that the table Arbeitseinteilung gots 42 reads.
>
> SELECT * FROM ARBEITSEINTEILUNG AS a where a.baustelle = '12345' AND
> a.DATUM >= '05.10.2015' AND a.DATUM <= '11.10.2015';
>
> How can I improve the query?

Hmm, what is the execution time for both queries?

42 isn't a lot. This might also include accessing system tables ...


--
With regards,
Thomas Steinmaurer
http://www.upscene.com/

Professional Tools and Services for Firebird FB TraceManager, IB LogManager,
Database Health Check, Tuning etc.


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