BUG:10082277: Database Connections failing with ORA-4031

A short write-up on a problem faced in few newly upgraded databases to 11.2.0.1 : I faced this issue in couple of databases which were recently upgraded to 11gR2, the problem is so severe that even connecting using “/ as sysdba”  is not working and erroring out with <span style="font-family: arial,helvetica,sans-serif; font-size: small;">ORA-04031: unable to…

Simplified Approach to Resolve ORA-4031

After writing few Case studies and other related articles, I will be sharing my approach for Resolving ORA -4031 error. First we will see what ORA-4031 actually means. 04031, 00000, "unable to allocate %s bytes of shared memory (\"%s\",\"%s\",\"%s\,\"%s\")" // *Cause: More shared memory is needed than was allocated in the shared pool. // *Action:…

ORA- 4031 – A Case Study

Today I will be taking up one ORA-4031 issue we faced on one of our client database. Please note that SQL statements mentioned below have been changed and does not reveal any confidential information. Our client was facing ORA-4031 on a 9.2 database.This was a new Database which had gone Live recently. Following error messages…

Application Design and ORA – 4031

Much has been written on designing good application (which uses bind variables) so as to have better performance and avoid shared pool memory issues. Tom Kyte explains this on one of his post consequences of not using bind variables If you do not use bind variables and you flood the server with hundreds/thousands of unique…

Tweaking _Shared_pool_reserved_min_alloc and ORA – 4031

Here comes one more article dedicated towards diagnosing ORA- 4031 and related parameters. While googling on ORA-4031 error or working on TAR with Oracle Support you will most likely hit this parameter “_Shared_pool_reserved_min_alloc ” and find a advice for altering this parameter to 4000 or so. And many times you go and implement it as…

Shared Sub Pools

Today I will discuss about Shared pool subpools which have been introduced in release 9iR2 and higher (To be precise >9.2.0.5) and can be controlled by a hidden parameter “_kghdsidx_count ” Most of you would not have come across this term/parameter unless you have faced ORA-4031 error. As you all are aware that Shared Pool…