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From: Anil [mailto:[EMAIL PROTECTED]
Sent: Thursday, September 15, 2005 10:36 PM
To: 'mysql@lists.mysql.com'
Subject: QUERY CACHE TUNING QUESTION
Hi list,
We are using mysql 4.0.24 on RHEL 3.0 on dell 2650 machine with 2 gb RAM.
We tried to fine tune query cache . please find below the analysis
PARAMETER old modified
========== ========== ================
query_cache_size 10 MB 32 MB
Qcache_queries_in_cache 187 2444
Qcache_inserts 1226682 13560221
Qcache_hits 1510151 7380756
Qcache_lowmem_prunes 850128 8096499
Qcache_not_cached 2725692 16361318
Qcache_free_blocks 65 12
Qcache_free_memory 9.26 MB 28.79 MB
qCACHE HIT RATE 27.64% 19.78%
QCACHE HIT RATE IS CALUCULATED WITH FORMULA = (Qcache_hits/(Qcache_inserts
+Qcache_not_cached+Qcache_hits)) * 100
QCACHE HIT RATE IS CALUCULATED WITH FORMULA = (Qcache_hits/(Qcache_inserts
+Qcache_not_cached+Qcache_hits)) * 100
As per the above analysis we observed that qcache hit rate came down after
increasing query_cache_size from 10 MB to 32 MB and qcache_hits got
increased but the remaining parameters Qcache_inserts, Qcache_not_cached,
Qcache_lowmem_prunes also increased because of that hit rate came down
drastically. We didn't understand the reason behind hit . Is there any
recommended procedure to fine tune query cache . awaiting early reply from
list.
Thanks in advance
Anil
DBA
