Setting up TAF with Data Guard: A new ORA-16456 is coming!
Hi there Normally, all of us have already setup TAF for client connection in a dataguard configuration. We always do a simple check with a switch-over to show that a… Read more »
Category: 11g
Managing standby redologs in policy managed RAC configuration
Hi There, In a policy managed RAC configuration with dataguard also in RAC mode, sometimes it is getting hard to manage standby redo logs. From time to time, after a… Read more »
Logon trigger on active dataguard
Hi There, Normally this works fine! But today I just discovered that it could not work anymore when it has worked few weeks before. What the… I was able to… Read more »
Check access/filter predicate efficiency
Hi there, This some queries I am using to check access predicate efficiency. First two small functions. Access predicate: [code language=”sql”] CREATE OR REPLACE FUNCTION EXTRACT_ACCESS_PREDICATES (pIn varchar2, pOwner varchar2,… Read more »
Identify good candidate sql statements for Result Cache
Hi There, This the query I am using to identify good candidate sql statements for result_cache sqlpatch. [code language=”sql”] select s.sql_id,s.executions, round (s.cpu_time/1000000) cpu, round (s.ELAPSED_TIME/1000000) elapse, round ((s.ELAPSED_TIME/1000000)/ decode… Read more »
MView: Slow fast refresh on commit if column group on master table
Hi there Here is a customer case again on Documentum database. Oracle 11.2.0.4 on AIX power 8. [code language=”sql”] create materialized view log on dmi_queue_item_s WITH sequence, ROWID (item_id,name,task_name,task_subject,date_sent,router_id,delete_flag,dependency_type),PRIMARY KEY… Read more »
Join cardinality computation case
Hi there Giving an SQL tuning training session, I came to the following point: This query: [code language=”sql”] select count(prs.firstname), count(adr.zip_additional), count(mlg.dispatch_date) from addresses adr join recipients rec… Read more »
LogFileSync event can also be network related…
Hi there, what’s wrong on the picture bellow? When trying to get sql activity behind there is nothing. [code language=”sql”] select sql_id,wait_class, blocking_session from v$active_session_history where event =’log file… Read more »
Multiple awr report parser in perl
Hi there, The idea came to me while running an audit to identify bottlenecks in an Oracle infrastructure composed of two servers with many single instances. Due to lack of… Read more »
12c db_block_checking and db_block_checksum measured overhead
Hi There, I went to a customer today for a performance issue between test and production environment. Basically, a specific process was 5 times faster in test than in… Read more »