Mutexes And Changes in Library Cache - HrOUG
Mutexes And Changes in Library Cache - HrOUG
Mutexes And Changes in Library Cache - HrOUG
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Benefits of SESSION_CACHED_CURSORS<br />
DbProf.<br />
com<br />
• When cursor is <strong>in</strong> the session cursor cache then<br />
the cost of f<strong>in</strong>d<strong>in</strong>g cursor <strong>in</strong> SGA is m<strong>in</strong>imal.<br />
– less latch<strong>in</strong>g<br />
– less CPU<br />
– Concurrency improvement will apply only to already<br />
closed cursors which are afterwards reparsed several<br />
times.<br />
• Negative effect: cursors are partly p<strong>in</strong>ned (heap<br />
0) and therefore we should check the size of<br />
shared pool.<br />
• More cached cursors less candidates for ag<strong>in</strong>g<br />
out – for free<strong>in</strong>g memory!!!<br />
www.dbprof.com - © 2012 Jože Senegačnik<br />
Oracle ACE Director<br />
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