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Showing posts from October, 2007

Intereseting --- 249 days bug for Oracle on Linux servers

--contributed by Manjunath Ulthi, Senior DBA at Infosys Technologies limited

1 Introduction

Problem: OCI client spins when machine uptime >= 249 days in Linux machines. Once the uptime crosses 249 days the database client hangs and leads to high CPU utilization and server hung state. The user will not be able to connect to the databases This is oracle known bug 4612267.

Solution: This can be handled by applying the patch 4612267.

The patch has been applied in the servers server126, server041 & server120 and tested. After the patch has been applied the client connections were normal after 249 days and all the operations of databases/applications were normal and didn’t encounter any problems.

For further information refer the Metalink Notes

Note: 338461.1: SQL*Plus With Instant Client Hangs, When System Uptime Is More Than 248 Days

Note:4612267.8 : Bug 4612267 - OCI client spins when machine uptime >= 249 days

2 General Instructions

Procedure to apply the patch

1. Download the …

The art and science of Oracle DB performance tuning

Back to square one, where I started this blog ? ...

Nooooo ... Here I am not providing a step by step procedure for Oracle performance tuning, however a framework to help a DBA with tackling Oracle performance issues. This could be seen as a reference to understand where to start, what information to collect, where to proceed, how to conclude, etc. .

Without much ado, let's go ahead.

What's the problem ?

Some of us (DBA's) get bad performance notice from users & we might tend to directly jump into trying to find a solution. Instead of trying that, a better way to do that is to first find out what that problem is & how is it seen by the user. First, start with these questions asking the requestor :

1 Is the whole application slow or only some modules are slow ?
2. When did you first notice this problem ?
3. Is the problem noticed all of sudden? Is it gradual ?
4. Is it recurring as you mentioned ?
5. Is there any recent upgrade to application ?
6. Is there…