Re: Vacuum question..

On 30 Sep 2002 at 20:08, Williams, Travis L, NPONS wrote:

> I have a DB that's about 1000 rows and 100 columns with 97 of them being updated every 20-30 min.  This DB is
basicallyall of the data that I poll off of 1000 different machines thats used by different scripts.  How often should
Irun Vacuum?  Would I be better off doing it every time after I  
do my updates?

Well no. I would say every 15 minutes would be a good idea.

How often do you query the table? Vacuum can do three things for you.

1) Update statistics so that planner chooses correct plan thus improving
performance.

2) Update causes dead tuples of earlier verson. Vacuum analyze marks these dead
tuples for reuse so that resources are used efficiently.

3) Vacuum full also retrieves any lost disk space when you do a bulk delete.

Clearly in your case, (2) seems to be predominant factor. So I would say a
vacuum analyze <tablename> for each 15 minutes will keep things in good
shape..Even half an hour would do..


Bye
 Shridhar

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