Oracle Performance & Memory Leak

[Donald Osbourne]

Hi,

Running Oracle 8.1.7.4 on HP/UX 11.0, I am experiencing problem with Oracle releasing the memory after the processe(s) are halted.

Before starting the database, the memory usage is 16% of 1.5 Gb of total memory. After starting the database it increases to 25% usage, and max at 95% during an import. Importing a single table takes several hours and the memory usage remains at 72% after halting the processes and shutting down the database, a problem that is only resolved by rebooting.

Thanks for any suggestion in resolving this problem.

Don. O.

[Jeff Schussele · Accepted solution]

Hi Don,

You really need to fire up glance or it's GUI version gpm & see what's using the memory.
It's very possible that the disk buffer cache is using up loads of memory. Default for the kernel parameter dbc_max_pct is 50% & *heavy* disk access - as in a huge import - could gobble up every bit of that 50% & it won't be released by the buffer until an application requests it.

HTH,
Jeff

[Tim Adamson_1]

I agree with previous response. The buffer cache will most likely be the culrpit.

Set dbc_max_pct to 15, regen the kernel and reboot. Then periodically monitor the memory usage using /usr/contrib/Q4/bin/kmeminfo..

I'm sure you will determine where the memory is going.


Tim.