Cause: The file header for the redo log contains a checksum that does not match the value calculated from the file header as read from disk. This means the file header is corrupted Action: Find and install correct version of log or reset logs.
This error appears when you try to issue a DDL against a global temporary table thats created with “on commit preserve rows” clause.:- create global temporary table TEST (object_id number, object_name varchar2(30)) on commit PRESERVE rows; Such tables get bound to the session with the first insert and then this binding is ONLY removed when…
This error appears when the process of starting up a dedicated server process failed and it could be either because the executable could not be found or the environment isn’t set up correctly. Turn on tracing at the ADMIN level and re-execute the operation. Tracing can be set by adding following clause in listener.ora file…
TNS:listener received no CONNECT_DATA from clientCause: No CONNECT_DATA was passed to the listener.Action: Check that the service name resolved from TNSNAMES.ORA has the CONNECT_DATA component of the connect descriptor. Below is the sample entry of tnsnames.ora:- #When using SERVICE_NAME in CONNECT_DATA componentorcl.example.com = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = myserver.example.com)(PORT =…
This post is to provide a script to auto-start Oracle Instances on Linux upon server restart. First step would be to configure /etc/oratab file as per your requirement, oratab file is in the following format: <DB NAME>:<ORACLE HOME>:<Y|N> The last letter tells oracle if the database need to restarted or not, so we would change…
Library cache pins are used to manage library cache concurrency. Pinning an object causes the heaps to be loaded into memory (if not already loaded). PINS can be acquired in NULL, SHARE or EXCLUSIVE modes and can be considered like a special form of lock. A wait for a “library cache pin” implies some other…
The library cache lock controls the concurrency between clients of the library cache by acquiring a lock on the object handle so that either: One client can prevent other clients from accessing the same object The client can maintain a dependency for a long time (no other client can change the object). This lock is…
There can be several situations where you want to test the impact of dropping a column from a table, till 11gR2 Oracle provided an option to mark a column as UNUSED before dropping a column, and do ALTER TABLE … DROP UNUSED COLUMNS at a later time but marking a column UNUSED is a irreversible…
Until 11gR2 to move a table to different tablespace there were two available methods, first one was ALTER TABLE .. MOVE TABLESPACE but during this the table was locked for DML, thus downtime and the second one was DBMS_REDEFINITION which will allow to create a new table on the desired tablespace and sync the data…
With 12cR1 you can now move table partitions and sub-partitions online. There are lot of reasons for which you might want to move a table partition or sub-partition such as:- Re-cluster data and reduce fragmentation. Move a partition to another tablespace. Modify create-time attributes. Store the data in compressed format using table compression. The problem…
Oracle Database Internal Mechanism 