Thread

1. memory leaks fixed?

   Nick T <ntaylor84@earthlink.net> — 2001-04-05T13:56:58Z

   Hi all:
   
   Just finished reading all of the comments at
   
   http://openacs.org/philosophy/why-not-mysql.html
   
   and became concerned about the comments regarding severe memory leaks with
   PostgreSQL.  Is this true?  Have they been fixed?  Are there any
   workarounds?
   
   Thank you
   
   Nick
   
   
   
   

2. Re: memory leaks fixed?

   Denis Perchine <dyp@perchine.com> — 2001-04-08T07:13:17Z

   Hello,
   
   > Just finished reading all of the comments at
   >
   > http://openacs.org/philosophy/why-not-mysql.html
   >
   > and became concerned about the comments regarding severe memory leaks with
   > PostgreSQL.  Is this true?  Have they been fixed?  Are there any
   > workarounds?
   
   There are some still. Although not that large as mentioned in the comments.
   If you have long-running cursor, and tables involved in this cursor are 
   heavily updated, you will end with 200Mb postmaster in 1-2 days.
   
   -- 
   Sincerely Yours,
   Denis Perchine
   
   ----------------------------------
   E-Mail: dyp@perchine.com
   HomePage: http://www.perchine.com/dyp/
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   ----------------------------------
   
   

3. Re: memory leaks fixed?

   Peter Eisentraut <peter_e@gmx.net> — 2001-04-08T11:05:38Z

   Nick T writes:
   
   > Just finished reading all of the comments at
   >
   > http://openacs.org/philosophy/why-not-mysql.html
   >
   > and became concerned about the comments regarding severe memory leaks with
   > PostgreSQL.  Is this true?  Have they been fixed?  Are there any
   > workarounds?
   
   There are certain queries that require a seemingly unproportional amount
   of memory.  Up until verion 7.0, memory in the server was not recovered
   until the end of the transaction, so it was possible to run out of memory
   when it should have been avoidable.  This is technically not a memory
   leak, just a less than optimal use of resources.  However, because of the
   way malloc/sbrk work, this memory is no longer available to the operating
   system, so it looks like a memory leak.
   
   7.1 uses a better technique to handle the allocated memory, which should
   fix most of these cases.  In any case it should be possible to rewrite the
   queries, but there is no general procedure on how to do that.
   
   -- 
   Peter Eisentraut      peter_e@gmx.net       http://yi.org/peter-e/