Oracle Wait Events | #dailyDBA 41

0:00 #dbaChallenge: what changes you will make inside Oracle database to avoid ORA-1555 error?

0:45 When is the best time to gather table / schema stats?
3:17 What is your recommendations on DB block size for OLTP and data warehouse systems?
6:05 Difference between Oracle 10g and 11g?
8:56 My database archive space gets full every week. I have to remove archives manually "RMAN delete archivelog all;" Any workaround?
10:26 What are wait events inside Oracle Database?
Bonus Question:
14:27 How ORACLE DBA interviews are conducted?

[shahidkhan-iqgb]

What is the scope of oracle dba in future?

[shineshvv]

For ORA 1555 Run the undo advisor increase the undo retention and if needed add undo data files to Undo

[santoshmishra-mygc]

I would say 16kb for warehouse, that will be useful for read operation and reduce I/O, as in one I/O it will read 16KB of data so more data will be read.

[bashaakku]

#dbaChallenge we can increase undo_rentention paramerter

[shehbazphulmamdi]

First of all need to check the query duration...if the query duration is more than undo retention then definately there will be a issue with query plan.
If the query duration is less than the undo retention then need to check what else causing the undo blocks to be overwritten..

[vidmayur]

Based on max querylen change the undo retention

[sachintiwari]

In 4th question, 8.56 min, if we use 'delete input' in backup archivelog than it will delete all the archivelog from production, and if we have DR server which might be not sync with Production, than we use delete input or Not ??
Please reply

[matheenahamed]

What is looping chain of synonyms?
ORA-01775: looping chain of synonyms. How to resolve this?

[santoshmishra-mygc]

Tune the query, ask application team to have implicit commit, if not possible then autoextend undo tablespace, let the query complete once complete turn off autoextend to off, shrink undo tablespace

[bharathkumar-dscd]

Hi Team,

BEGIN
DBMS_STATS.CREATE_STAT_TABLE (
ownname => 'dba1'
, stattab => 'opt_stats'
);
END;
/
-- generate representative workload
EXEC

BEGIN
(
ownname => 'dba1'
, stattab => 'opt_stats'
);
END;
/


BEGIN

ownname => 'dba1'
, stattab => 'opt_stats'
);
END;
/