> Are you absolutely sure that you really need all these indexes?

sure, and absolutely sure ! because it's a critical that select query return in < 100 ms, and for that we need all theses index :(

>
> ciao,
> André
>
>
> ~~~Ihre Nachricht~~~
>
> s> thanks ivan,
>
> s> yes i just try with force write off, and yes now i have
>
> s> Time to execute the sql: 16 ms
> s> Indexed Read: 117
> s> Non Indexed Read: 0
> s> Inserts: 30
> s> Updates: 0
> s> Deletes: 30
> s> Time to commit the data: 0
>
> s> the commit is now very fast (in apparence) but in fact it's not
> s> really help because if i execute five time the query, on the fifth
> s> (exactly on every fifth execute) i have
>
> s> Time to execute the sql: 0 ms
> s> Indexed Read: 117
> s> Non Indexed Read: 0
> s> Inserts: 30
> s> Updates: 0
> s> Deletes: 30
> s> Time to commit the data: 3202
>
> s> :( it's mean if i m unlucky when i execute the query that it is
> s> the flush time i loose :( i was thinking that the flush was done by
> s> a separate thread and not by a "commit" thread
>
> s> do you have any other idea how to speed up the commit ? the index
> s> is multi column (6 at max) ... do you thing reduce the number of column can help ?
>
> s> thanks you by advance
>
>
> s> --- In firebird-support@yahoogroups.com, "Ivan Prenosil" <Ivan.Prenosil@> wrote:
> >>
> >> > when i execute some SQL, the time to execute the sql is very fast (16ms) but the time to commit the data is very very slow (2293
> >> > ms, even some time more than 10 secondes !)
> >> >
> >> > Time to execute the sql: 16 ms
> >> > Indexed Read: 117
> >> > Non Indexed Read: 0
> >> > Inserts: 30
> >> > Updates: 0
> >> > Deletes: 30
> >> > Time to commit the data: 2293
> >> >
> >> > the tables where the record was inserted/deleted have lot of indexes (around 30 index by table, and around 10 columns by table)
> >>
> >> On commit, every page in FB cache changed by your transaction
> >> (and depending) must be written to disk.
> >> FB keeps database in consistent state by writing pages in specific order,
> >> and setting Forced Writes On prevents OS from optimizing those writes.
> >> So, modifying tables with lots of indexes like yours causes
> >> heavy disk trashing and so is slow.
> >> You should reduce number of indexes,
> >> or (if you can take that risk) turn Forced Writes Off.
> >>
> >> Ivan
> >> http://www.volny.cz/iprenosil/interbase/
> >>
>
>
>
>
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>