Re: PostgreSQL and mySQL database size question

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: ingham(at)erols(dot)com
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: PostgreSQL and mySQL database size question
Date: 2001-04-30 19:17:31
Message-ID: 19044.988658251@sss.pgh.pa.us
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"Fred Ingham" <ingham(at)erols(dot)com> writes:
> After dropping and recreating the indexes I have (in KB):

Ah, that's more like it.

> So, it appears that I am running into the pathological case.

Actually, a simpler explanation would be if you'd done a bunch of
updates and/or deletes at some point. VACUUM currently never shrinks
indexes, so the excess index space might just represent the peak size
of your tables. (Yes, improving that is on the to-do list.)

> In short, they are all needed for acceptable performance querying and
> retrieving values from the database.

You've got common queries that do selects with WHERE clauses referencing
each one of these columns? Possible, certainly, but seems a bit odd...

> With respect to mySQL, I did verify that mySQL did in fact have all of the
> indexes I created and that they were saved in a single file (the *.MYI).

Hm. Anyone know how mySQL represents indexes? That still seems awfully
small.

regards, tom lane

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