Re: iowait - Mailing list pgsql-novice

From Alan Hodgson
Subject Re: iowait
Date
Msg-id 200606091702.38286@hal.medialogik.com
Whole thread Raw
In response to iowait  (Tom Allison <tallison@tacocat.net>)
Responses Re: iowait  (Tom Allison <tallison@tacocat.net>)
List pgsql-novice
On Friday 09 June 2006 16:44, Tom Allison <tallison@tacocat.net> wrote:
> I am running it under 'BEGIN' so in theory autocommit is off, which seems
> to be the case since there aren't any rows to query.

The COPY would run as a single transaction, anyway.

> The whole thing is writing to a partition on a relatively simple EIDE
> disk.

And that's why it's slow.

>
> My iowait is 95-95% according to iostat and it's all pointed at this one
> disk partition.  And it's taking a REALLY long time.
>
> Question:
> Is this normal for a large data load like this?

Yep.

> Is there something "obvious" I could do in the future to better the
> situation? Or am I simply bound by the type of hardware I'm running it
> on?

Drop indexes before the COPY and recreate them after.  Other than that, not
much.

> Are the number of default values and primary key index going to be the
> death of me?

Default values aren't really a factor.  The index slows down COPY some.  The
reason it's slow is your hard drive, though.

--
When we vote for taxes, we are voting to steal from our neighbors


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