Posted by Riyaj Shamsudeen on June 15, 2012
Quick note about Jonathan Lewis trip to Dallas: Jonathan Lewis will be presenting two day seminar on two topics, “Beating the Oracle Optimizer” (June 28) and “Troubleshooting and tuning” (June 29th).
The event will be held June 28-29, 2012 at SMU-in-Legacy in Plano, TX.
This is a must-attend event for experienced DBAs and Developers. Especially, if you are planning to upgrade your database/application in the near-future or if you are in the middle of an upgrade, you must attend these two seminars. This seminar series provide enormous value resolving complex Production performance issues.
Click Here for details.
Posted in Performance tuning, Presentations | Tagged: cost based optimizer presentations, oracle performance | Leave a Comment »
Posted by Riyaj Shamsudeen on June 1, 2012
This is a quick note about reverse path filtering and impact of that feature to RAC. I encountered an interesting problem recently with a client and it is worth blogging about it, with a strong hope that it might help one of you in the future.
Environment is 126.96.36.199 GI, Linux 5.6. In a 3 node cluster, Grid Infrastructure (GI) comes up cleanly in just one node, but never comes up in other nodes. If we shutdown GI in first node, we can start the GI in second node with no issues. Meaning, GI can be up in just one node at any time.
System Admins indicated that there are no major changes, only few bug fixes. Seemingly, problem started after those bug fixes. But there were few other changes to the environment /init.ora parameter change etc. So, the problem was not immediately attributable to just OS changes.
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Posted in Oracle database internals, Performance tuning, RAC | Tagged: "has Disk HB, advanced RAC training, but no Network HB", cssd not joining cluster, RAC performance, reverse path filtering, rp_filter | 11 Comments »