String Aggregation Techniques:


DB time link:


Harnessing the Power of Optimizer Hints:


Index Rebuild online: What happens in the background?


+++++++++++++++++Execution plans+++++++++++++++++

Execution plans : blocking and non-blocking operations


How To Change Execution Plan Of Query Without Modifying SQL Code:


Interpreting Explain Plan:


Comparing Plans:



Buffer Sorts:


Instance Tuning Using Performance Views:


Automatic partitioning in 12cr2:


Adaptive Cursor Sharing:


Bind-Sensitive Cursors:


+++++++++++++++++Shared pool+++++++++++++++++


How Parsing in Oracle Causes Contention for Shared Pool and Library Cache Latches:


14 Tuning the Shared Pool and the Large Pool



Database Performance Tuning Guide:


How to read PGA memory advisor in AWR:


Monitoring Open and Cached Cursors:


+++++++++++++++++WAIT EVENTS++++++++++++++


enq tx - index contention oracle 11g:


direct path read wait event in oracle 11g:


db file parallel read wait event oracle 11g:


CPU in AWR Report tips:


User Calls (per second)


Difference between "db file scatterd read" and "db file sequential read":




+++++++++++++Latch Issues+++++++++++++++++

Resolving Latch Contention:


Library cache latch contention:


Troubleshooting: Contention – Library cache lock – Oracle Database



+++++++++++++Display_cursor plan+++++++++++++


select * from table(dbms_xplan.display_cursor('sql_id',0,'ADVANCED')); --> other options: PROJECTION -BYTES  RUNSTATS_LAST


select sh.snap_id, sh.instance_number inst, sh.begin_interval_time, s.sql_id, s.plan_hash_value, nvl(s.executions_delta,0) execs, (s.elapsed_time_delta/decode(nvl(s.executions_delta,0),0,1,s.executions_delta))/1000000 avg_etime, (s.buffer_gets_delta/decode(nvl(s.buffer_gets_delta,0),0,1,s.executions_delta)) avg_lio from DBA_HIST_SQLSTAT S, DBA_HIST_SNAPSHOT SH where s.sql_id = '&sqlid' and sh.snap_id = s.snap_id and sh.instance_number = s.instance_number order by 1, 2, 3


++++++++Sql Trace & Autotrace+++++++++++++



Sql Trace:

Yet another DBA blog: TRACEFILE_IDENTIFIER - Another useful parameter



Thanks & Regards,

Mukesh Kumar Jha