We've got about 30 sites all running the same application, and I'm consistently seeing large numbers of 106 (library cache) latch free waits. They tend to happen at peak times during the day, and in the worst case I saw 12 sessions all on a 106 latch free wait event, spread across 3 P1RAW addresses.
Running Steve Adams latch_sleeps scripts, yields the following: LATCH TYPE IMPACT SLEEP RATE WAITS HOLDING LEVEL ------------------------------------- ----------- ---------- ------------- ----- library cache 1281502 0.11% 2399666 5 cache buffers chains 273556 0.00% 23049 1 shared pool 73893 0.04% 91633 7 cache buffers lru chain 12236 0.01% 70756 3 session allocation 10639 0.06% 19969 5 row cache objects 7835 0.00% 29816 4 cache buffer handles 3646 0.00% 2575 3 transaction allocation 2344 0.01% 4341 8 enqueue hash chains 1831 0.01% 13722 4 redo writing 778 0.01% 17328 5 session idle bit 714 0.00% 0 1 The results above are from an instance which has been up for 5 days As you can see, library cache latch has a big impact (though I must admit, I'm not sure what Steve's IMPACT formula actually tells me). When I check across other sites, I see a similar pattern - large numbers of 106 latch misses and sleeps. I guess what I'd like to know is where these latches are happening, which objects / cursors etc are causing the contention. I've grappled with SQL against x$kglob, trying to join back to the P1RAW but am not getting very far. Any ideas? TIA. Neil. -- This correspondence is confidential and is solely for the intended recipient(s). If you are not the intended recipient, you must not use, disclose, copy, distribute or retain this message or any part of it. If you are not the intended recipient please delete this correspondence from your system and notify the sender immediately. No warranty is given that this correspondence is free from any virus. In keeping with good computer practice, you should ensure that it is actually virus free. E-mail messages may be subject to delays, non-delivery and unauthorised alterations therefore, information expressed in this message is not given or endorsed by Sx3 unless otherwise notified by our duly authorised representative independent of this message. Sx3 is a trading name of Service and Systems Solutions Limited, a limited company registered in Northern Ireland under number NI 32979 whose registered office is at 120, Malone Road, Belfast, BT9 5HT. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Harvey Neil INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
