Horton

Re: Significantly larger toast tables on 8.4?

Merlin Moncure <mmoncure@gmail.com>

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From: "Merlin Moncure" <mmoncure@gmail.com>
To: "Alvaro Herrera" <alvherre@commandprompt.com>
Cc: "Peter Eisentraut" <peter_e@gmx.net>, "James Mansion" <james@mansionfamily.plus.com>, pgsql-hackers@postgresql.org, "Stephen R. van den Berg" <srb@cuci.nl>, "Alex Hunsaker" <badalex@gmail.com>, "Robert Haas" <robertmhaas@gmail.com>, "Tom Lane" <tgl@sss.pgh.pa.us>
Date: 2009-01-05T16:55:03Z
Lists: pgsql-hackers 
On Mon, Jan 5, 2009 at 11:45 AM, Alvaro Herrera
<alvherre@commandprompt.com> wrote:
> Peter Eisentraut escribió:
>> James Mansion wrote:
>>> Peter Eisentraut wrote:
>>>>> c. Are there any well-known pitfalls/objections which would prevent
>>>>> me from
>>>>>    changing the algorithm to something more efficient (read: IO-bound)?
>>>>
>>>> copyright licenses and patents
>>>>
>>> Would it be possible to have a plugin facility?
>>
>> Well, before we consider that, we'd probably want to see proof about the
>>  effectiveness of other compression methods.
>
> I did some measurements months ago, and it was very clear that libz
> compression was a lot tighter than the PGLZ code.

we have seen amazing results with lzo compression...2-3x faster
compression times with only 10-15% less compression:

There are tons of supporting examples online, for example:
http://mail.jabber.org/pipermail/standards/2005-October/008768.html

I think, if the database is automatically compressing things (which,
IMO, it shouldn't), a low cpu overhead algorithm should be favored.

merlin