From: | Zeugswetter Andreas SB <ZeugswetterA(at)wien(dot)spardat(dot)at> |
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To: | "'Matthias Urlichs'" <smurf(at)noris(dot)de> |
Cc: | "'pgsql-hackers(at)postgreSQL(dot)org'" <pgsql-hackers(at)postgreSQL(dot)org> |
Subject: | AW: Berkeley DB... |
Date: | 2000-05-25 15:47:52 |
Message-ID: | 219F68D65015D011A8E000006F8590C604AF7DA5@sdexcsrv1.f000.d0188.sd.spardat.at |
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Lists: | pgsql-hackers |
> ... that being said (and I took a quick test with 10000
> randomly-inserted
> records and fetched them in index order) if the data's in the
> cache, the
> speed difference is insignificant.
As long as everything fits into the system cache and is
already in there, this test is moot.
> I did this:
>
> create table foo (a int not null,b char(100));
> create index foo_a on foo(a);
> for(i=0; i<10000; i++) {
> insert into foo(a,b) values( `((i*3467)%10000)` , 'fusli');
> }
here you need to reboot the machine or make sure nothing is cached.
then time the following and make sure it uses the index afterwards.
> select a from foo order by a;
Andreas
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