Re: Considering Solid State Drives - Mailing list pgsql-general

From Radosław Smogura
Subject Re: Considering Solid State Drives
Date
Msg-id 201011111221.31556.mail@smogura.eu
Whole thread Raw
In response to Considering Solid State Drives  (Allan Kamau <kamauallan@gmail.com>)
List pgsql-general
Hello,

When choosing SSD drive you need to consider
* number of writes to particular sector which is about 100k to 200k and then
sector will fail
* in case of DB grow, limitied size of those dirvers.

> As part of datamining activity. I have some plpgsql functions
> (executed in parallel, up to 6 such concurrent calls) that perform
> some reads and writes of large number of (maybe 10000) records at a
> time to a table having multi-column primary key.
> It seems the writing of these few thousands records is taking a long
> time (up to 5mins in some cases).

This time is realy long, it is about 30 seconds to insert one row!
You should check if your functions dosen't generate locks, check if some
triggers are executed. Your functions can query on non-indexed columns, as
well. Try to execute above functions in one, non-paraller thread, if the time
per row will be less then paraller execution it means you generate locks.

You can as well try to disable fsync in PSQL config.

Kind regards,
Radek

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