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latch: row cache objects takes 80% of database time

stee1ratNov 21 2012 — edited Nov 26 2012
Hello, All!

I'm new to this forum and i'm not sure if i'm able to post questions like this here.

I'm facing the problem with really high concurrences for row cache objects in a database.
Could someone help me to find the reason for it or send me in the right direction in my searching?

Here's the excerpt from AWR for last 3,5 hours:
Top 5 Timed Foreground Events
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                                           Avg
                                                          wait   % DB
Event                                 Waits     Time(s)   (ms)   time Wait Class
------------------------------ ------------ ----------- ------ ------ ----------
latch: row cache objects        127,452,881   3,058,038     24   80.3 Concurrenc
cursor: pin S wait on X             476,147     271,907    571    7.1 Concurrenc
db file sequential read          22,066,495     233,666     11    6.1 User I/O
DB CPU                                          193,349           5.1
library cache: mutex X            5,000,294      17,950      4     .5 Concurrenc


Dictionary Cache Stats               DB/Inst: ---------  Snaps: 26314-26328
-> "Pct Misses"  should be very low (< 2% in most cases)
-> "Final Usage" is the number of cache entries being used

                                   Get    Pct    Scan   Pct      Mod      Final
Cache                         Requests   Miss    Reqs  Miss     Reqs      Usage
------------------------- ------------ ------ ------- ----- -------- ----------
dc_awr_control                     769    0.0       0   N/A       28          1
dc_files                        15,318   39.6       0   N/A        0        666
dc_global_oids                  37,214    4.8       0   N/A        0         43
dc_histogram_data         1.537971E+09    0.0       0   N/A        0     21,233
dc_object_grants               143,088    0.9       0   N/A        0        187
dc_objects                 143,387,924    0.0       0   N/A        9      6,471
dc_profiles                    382,829    0.0       0   N/A        0          1
dc_rollback_segments         1,416,812    0.0       0   N/A        0     10,272
dc_segments                 33,731,523    0.1       0   N/A       21      4,126
dc_sequences                       907   56.0       0   N/A      907          6
dc_tablespace_quotas                36   47.2       0   N/A        0          2
dc_tablespaces               2,301,889    0.0       0   N/A        0        158
dc_users                    61,573,004    0.0       0   N/A        0        268
global database name           391,810    0.0       0   N/A        0          1
outstanding_alerts               3,480  100.0       0   N/A        1          0
          -------------------------------------------------------------
The version of database is 11.2.0.2.0

Edited by: user2586601 on Nov 21, 2012 3:53 AM
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Locked on Dec 24 2012
Added on Nov 21 2012
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