Oracle memory usage & top

Hi,
 We have an Oracle installation on a SUN Ultra-1 running SunOS 5.5  (Solaris). Oracle is used in a web context, so there is always  5 connections to the database open. No other applications are  running on the machine except for the servers that connect to the  webserver (through the protocol fastcgi).

 The problem we experience is ocnnected to memory usage. When  using top we get a rapported amount of 17MB free memory and a total  amount of 309MB. However, just a few weeks back the machine used  to run on 215MB and we had the same quantity of free memory. This  is strange since one would expect the amount of free memory to  increase when the size of internal memory increases.

 When analysing the situation with top, a typical oracle instance  lists as follows (we have 5 of those process running):

Memory: 309M real, 10M free, 200M swap, 546M free swap

  PID USERNAME PRI NICE SIZE RES STATE TIME WCPU CPU COMMAND 11496 daemon 5 0 123M 7184K sleep 0:07 3.26% 3.26% oracle

 However when using top and summing up the RES field (e.g. top 500),  then the amount of resident memory only sums up to 140MB and not 299MB  which would be expected (309 - 10).

 Questions:

• Which are the best tools to analyze memory performance when using Oracle in the above context?
• top seems to give incorrect results, are we perhaps using it incorrectly?
• Oracle seems to consume a gigantic amount of memory (even though most of it is swapped out). Any traps to look out for? Any setting in the installation that might be adjusted?

 Any pointers/ideas etc are more than welcome!

 Thanks,
 Stefan

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Stefan Farestam              IGIS - Industrial Grade Information Systems
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