Monday, February 04, 2008

Rolling invalidations Addendum

If you enable cursor trace for the testcase in my previous post using the method described in http://el-caro.blogspot.com/search?q=unshared

The generated trace in udump will have the following

************************************************************
kksCheckCursor: pinning child #0 in shared mode 7d42bd0e8 7d7e87600
Failed sharing : Rolling invalidation
kksUnlockChild: releasing child
Failed sharing : 800000000000
kksSearchChildList: no suitable child found
Creating new child object #1
kksLoadChild: reload 0 child_reload 0
kksLoadChild: reload 0 child_reload 0
Compilation environment difference Failed sharing : 0
Change in cursor environment
************************************************************

Also the parameter _optimizer_invalidation_period does not work for statements using PQ. This can be tested by changing the degree of the table to 4 (say) and running the same test. In this case a new child cursor is generated on the first re-execution of the statement after stats are gathered even when the auto_invalidate flag is used.

3 comments:

Ranjan said...

Hi Fairlie ,

I read one of your blogs published about Oracle Dataguard .I have a related question . I am just trying to learn this technology. Well I have a physical Database and i have around 150 archive logs on them . Now overall space is around 15 MB of these on both the primary and the standby. Now since this is taking up too much space, I want to delete them . How can this be done ? Can I delete archive logs ?

Fairlie Rego said...

Is your question related to deleting archivelogs from the primary or the standby?

look at the RMAN archivelog deletion policy which has an option
"APPLIED ON STANDBY"

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