Sunday, December 12, 2010

Tablespace report




Run the following sql to get the space report in Oracle

Archiver Hung in Oracle database - ORA-16038, ORA-19504, ORA-00257

Archiver Hung in Oracle database

Steps to delete archive log file not needed for recovery (older than the last backup of the database)

Summary
1. check how much space is used by archiver
2. check the last good backup of the database
3. delete archive log files older than last good backup
4. crosscheck archive log

Friday, December 10, 2010

Blocking in Oracle Database

Follow the steps to locate and terminate blocking session from Oracle database (10g & up). Blocking_session_status contains ‘VALID’ when blocking_session is populated in 10g and up.
steps:
1. Display blocked session and their blocking session details
2. Find what is Blocking session Doing
3. Find sid and serial # of blocking session
4.  To terminate the session:

Thursday, December 09, 2010

nfs volumes on Linux


-         Set the mount options explictly. Here are the mount options that need to be used for nfs volumes on Linux.

Use : rw,bg,hard,nointr,rsize=32768,wsize=32768,tcp,vers=3,timeo=600,actimeo=0

default rsize and wsize for NFS is 4096 Blocks so if you have rsize=32k and wsize=32k then NFS would be able to read and write large datagram as compared to deafult one TCP option will make sure that your client are getting the data or not Hard & INTR - The program accessing a file on a NFS mounted file system will hang when the server crashes. The process cannot be interrupted or killed unless you also specify intr. When the NFS server is back online the program will continue undisturbed from where it was. actimeo is for access timeout and it should be 0 .
Hope this Helps!. Rupam

Monday, December 06, 2010

Table lock in Oracle


Explanation

Dropping or truncating a table requires you to acquire an exclusive lock on the table. A table is a "busy" resource if there are other sessions modifying or holding a lock on the same table.