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Home -> Community -> Usenet -> c.d.o.server -> Re: Setting shared pool size and Java pool size on 9i
The problem is in the large pool I think.
Large pool is used for:
a. pararallel executions b. dbwr_io_slaves c. in a MTS (multithreaded server) environment.I assume the first two are not applicable here. Are you running MTS? (Check the mts% init.ora parameters) If not: set large_pool_size=0, any other setting is a waste.
In MTS mode the PGA and/or UGA (I always forget: one of them or both)
memory moves to the shared pool.
When large pool is set, it moves from the shared pool to the large pool.
This is to prevent fragmentation in the shared pool.
Or you set large_pool_size=0 (PGA stays in the shared pool) or you set it to
an appropriate value, and 1M is not appropriate. The error mentions the
large pool is the problem.
In V8.0 large pool was taken from the shared pool, so shared_pool_size - large_pool_size remains for usual shared pool purposes. Don't know if this is still the case in V8.1 (what are you running??)
A query on V$SESSTAT (join with V$STATNAME to find the proper statistic)
shows you the amount of PGA each session currently uses and can be used to
find a proper value for the large_pool_size parameter.
The size is very application depended but if I recall it well it was about
250Kb per session in my situation.
V$SGASTAT shows how much of each pool is used (but shared_pool free_memory
is not the real free memory, it's better described as "never used")
Check the description of V$SHARED_POOL_RESERVED to see what it can tell you
(like how many ORA-4031 errors have occured since db uptime and how much
memory was lacking).
Eric Giguere <rikgig_at_yahoo.com> schreef in berichtnieuws
806a5f84.0212110644.111f6be0_at_posting.google.com...
| Hi all
|
| Ok, we have quite a nasty problem here. We are currently developping a
| web service using Tomcat, jsps and so on. We are running on a Solaris
| server with Oracle on the same machine as DB server.
|
| On one specific server, we have 1Gig of RAM and we constantly hit
| ourselves with out of memory errors from Oracle. Typically, we hit
| this error :
|
| ORA-04031: unable to allocate 8132 bytes of shared
| memory ("large pool","unknown object","cursor work
| he","qesaQBInit:buffer")
|
| And often, we also have the "shared pool" instead of the large pool.
| Our system is of course aimed at serving many different users at the
| same time. Right now, logging in with 5 people is enough to make it go
| down in about 30 - 45 minutes, Oracle getting out of memory in one of
| those pools (shared or large).
|
| Our current settings for the shared pool is : 592 Megs! The large pool
| is at 1 Meg.
|
| Can anyone explain the dynamics behind those pools and the reasonable
| values to put there so that the system may, for instance, serve 20
| clients simulatneously?
|
| Any help on this issue will be greatly appreciated :)
| Eric
Received on Wed Dec 11 2002 - 13:21:58 CST
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