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From: Warwick Hunter <whunter(at)agile(dot)tv>
To: Chad Thompson <chad(at)weblinkservices(dot)com>
Cc: pgsql-novice <pgsql-novice(at)postgresql(dot)org>
Subject: Re: BLOBs
Date: 2002-08-15 23:27:10
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-novice

I am using PostgreSQL to store BLOBS. I can't say that the
performance I am getting is wonderful, but it is adequate
for my purposes for now. Few people are every satisfied
with the performance of their database anyway :-)

I have done some performance testing on PostgreSQL and have
discovered that on an Linux Intel machine with reasonably fast
SCSI discs I can get average performance numbers like these:

Binary BLOB Size
300 KB read=24  ms write=185 ms del=105 ms
150 KB read=11  ms write=90  ms del=51  ms
   5 KB read=2.5 ms write=14  ms del=11  ms

I have done a small amount of tuning of the PostgreSQL
configuration. I plan to do some more.

> Or is storing BLOBs in a DB a good idea?

I have found PostgreSQL to be quite robust. I have a
test that deliberately kills the postmaster and postgres
subprocesses while doing write operations to see if I
can cause the database to be corrupted. This test
rarely fails.

This test fails more regularly if you rewrite the
data of an existing BLOB rather than create a new
one and delete the old one. So now I only ever create
a new BLOB.

I have seen one instance when the power on a machine
failed while writing a BLOB caused one BLOB to not
be restored correctly when the database came up.
I plan to investigate this and report a bug if

I looked at the bytea data type for storing my objects
as regular columns. However I was unable to make it work
with the normal SQL statements, the binary data always
upset the SQL command and the escaping routines didn't
seem to help.

Warwick Hunter                    Agile TV Corporation
Voice: +61 7 5584 5912            Fax: +61 7 5575 9550

In response to

  • BLOBs at 2002-08-15 17:41:30 from Chad Thompson


  • Re: BLOBs at 2002-08-16 04:26:27 from Aurangzeb M. Agha

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Next:From: Aurangzeb M. AghaDate: 2002-08-16 04:20:48
Subject: Re: Is my database done for?
Previous:From: Clinton AdamsDate: 2002-08-15 18:40:23
Subject: Re: Distinct On

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