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Low EST_PGA_CACHE_HIT_PERCENTAGE
Hi Friends,
While analysing the AWR report of Oracle 11g, In PGA TARGET Advisory i found low est_pga_cache_hit_percentage at size_factor =1.
If I increase the PGA_AGGREGATE_TARGET size will it improve the performance of the queries that accessing SORT/MERGE/HASH paths.
or
Should i found the queries accessing SORT/MERGE/HASH paths and tune them?
Which will be preferred one. Will that application to Dataware-house also?
please suggest.
Thanks & Regards,
Saranya
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What version of Oracle are you using and what operating system? Other than the
PGA cach hit percent, are you seeing any performance issues?
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What version of Oracle are you using and what operating system? Other than the
PGA cach hit percent, are you seeing any performance issues?
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Saranya --
Couple of questions and some task to do...
1- Is this a Data Warehouse or an OLTP database? one of your comments suggest DWH.
2- You said you are seeing low pga_cache_hit_percentage ... what's the value?
3- How big is your current PGA?
4- How big is your SGA?
5- How much memory do you have in the host?
6- Is there anything else running on this host other than this particular Oracle instance?
7- Please run query below and post results...
select
round(pga_target_for_estimate /1024 /1024 Target_MB,
estd_pga_cache_hit_percentage,
estd_overalloc_count
from
v$pga_target_advice ;
Thank you
Pablo (Paul) Berzukov
Author of Understanding Database Administration available at amazon and other bookstores.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.
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