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From: shlam@ie.cuhk.hk
To: Paul M. Aoki <aoki@postgres.Berkeley.EDU>
Cc: shlam@ie.cuhk.hk
Cc: postgres@postgres.Berkeley.EDU
Cc: shlam@ie.cuhk.hk
Subject: Re: how to clean up pg_log, pg_time and pg_variable?
Date: Mon, 06 Jun 94 18:14:43 +0800
Message-ID: <9406061014.AA14726@eng.ie.cuhk.hk> (raw)
In-Reply-To: <199406060957.CAA13241@faerie.CS.Berkeley.EDU>

>> I discover that the size of $postgres/data/pg_log, pg_time and
>> pg_variable grow very large.

>pg_variable should never grow beyond one disk page (8k).

>with respect to the other two, pg_log grows at 2 bits (.25 bytes) per
>transaction and pg_time grows at 4 bytes per transaction.

>> Is there any command to clean up or reset these files ?

>what pg_log and pg_time store are the commit status and commit time of
>each transaction.  in theory, this could be compressed by something
>like run-length encoding (since most transactions commit) or truncated
>after vacuuming (if you could somehow arrange to vacuum the entire
>installation..).  in fact, they just grow.

>it would be a bad idea to remove them or truncate them.

However, the pg_time  eat up 40M disk space and pg_log also ~20M
something. Is there any tools to compress this files or expire some of
the information in these log files?


Thanks.

Alan S. H. Lam
Department of Information Engineering, CUHK, Hong Kong
E-mail: shlam@ie.cuhk.hk 
Tel: (852) 609 8364 Fax: (852) 603 5032

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  To: postgres@postgres.berkeley.edu
  Cc: shlam@ie.cuhk.hk, aoki@postgres.Berkeley.EDU
  Subject: Re: how to clean up pg_log, pg_time and pg_variable?
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