Indexing is very important concept both for DBA & Developers. If used efficiently, it’s very useful. But some time index doesn’t show actual expected performance. In those cases we need to check whether index need to be rebuild or not. The reasons can be: As a result of row deletes, the number of index […]
SQL Plan Management
When a SQL statement is hard parsed, the cost based optimizer produces several execution plans and selects the one with the lowest cost. If a SQL plan baseline is present, the optimizer compares the plan it just produced with the plans in the SQL plan baseline. If a matching plan is found that is flagged […]
Best Practices for Statistics Gathering on Oracle 11g
1) Run all queries against empty tables to populate column usage (histograms will be gathered based on this column usage). 2) Run stats after data has been loaded but before indexes are created (the creation of the index gathers stats on them automatically). 3) Find (business) correlations between columns and inform the optimizer about these […]
Weblogic : Faster Startup time for Weblogic Server
At one of the biggest SOA implementation in UK, I have seen SOA servers taking more than 30-40 mins. One of the ways to reduce the startup time for servers is by using class caching. Weblogic Server allows us to use class caching to reduce the search time for classes and thus reducing the server […]
Performance Issue: Task PLP_APXACTSGROUPACCOUNT_A1_LOAD Takes a Long Time to Complete
Recently I observed that ETL was taking a very long time. Upon analysis I found out that STEP: PLP_APXACTSGROUPACCOUNT_A1_LOAD that was previously completed in 17-18 mins, is been running for 5-6 hrs and there was hardly anything processing happening on data warehouse side. It seems to happening only in version 7.9.6.2 and 7.9.6.3 and does not have any […]