Sorry, forgot a column in my description of the indexes :(
So here I go again:
I was surprised to see that sometimes the cache is not efficient.
for example, if I do:SELECT A.x, B.y FROM A,BWHERE A.col1='VALUE'AND A.col2 =
B.col3; With indexes Idx1: A.col1 , A.col2, A.x Idx2: B.col3, B.y...
and execute it several times, I get almost always the same response time
(around 1.5 ms in my case).Is sqlite only relying on the disk cache for the
data or am I missing something here ?
Renaud
> From: [EMAIL PROTECTED]> To: sqlite-users@sqlite.org> Date: Thu, 18 Oct 2007
> 06:52:47 +0000> Subject: [sqlite] Cache / performance when doing only select
> > > > Hello sqlite users !> > I have noticed that some people (like me) want
> to use sqlite in a read only environment.> Basically, we only do select
> commands, but we want them to be as fast as possible.> A bit like CDB, but
> with SQL queries.> > Is there any compilation hint or any way to hack sqlite
> to make it faster in such an environment (get rid off the transactions for
> example) ?> For the moment, I > - have synchronuous off, > - re-use queries
> prepared in advance.> - have only one big transaction for the whole run> >
> Also,I was surprised to see that sometimes the cache is not efficient.> For
> example, if I do:> SELECT A.x, B.y > FROM A,B> WHERE A.col1='VALUE'> AND
> A.col2 = B.col3;> > With indexes> Idx1: A.col1 , A.x> Idx2: B.col3, B.y> >
> and execute it several times, I get almost always the same response time
> (around 1.5 ms in my case).> Is sqlite only relying on the disk cache for the
> data or am I missing something here ?> > Cheers !> Renaud>
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