What is the shared pool ? Oracle keeps SQL statements, packages, object information and many other items in an area in the SGA known as the shared pool. This sharable area of memory is managed as a sophisticated cache and heap manager rolled into one. It has 3 fundamental problems to overcome: The unit of … Read more
When you are taking backups regularly to a specified disk then after some period of time the backup disk will get full and you will need to delete old backups to make space for new backups. Usually you delete the old backups manually by following a particular rule like, deleting all the backups taken before … Read more
While trying to rollback the conflicting patch 18893947 applying patch 21967332 Following executables are active <dir>/product/12.1.0/12c/lib/libclntsh.so.12.1 The file libclntsh.so.12.1 will be present when emagent is running on the node and will periodically use the library libclntsh.so.11.1 Follow below steps: As root user 1. Run grep command to check and find process id active executable libclntsh.so … Read more
The undo tablespace can have many datafiles, but if it has at least 1 datafile with autoextend=on then the tablespace will use the first approach, it will set the undo retention time based on statistics of the database gathered. MMON will calculate the value of “tuned_undoretention” based on the “maxquerylen” that checks every 30 sec … Read more
Determine if a Specific MVIEW is Being Refreshed: Determine if a Refresh Group is Being Refreshed There are two possible ways of refreshing a refresh group: -> refresh is being run by a job queue process in the background. -> refresh is being run manually inside Sql*Plus or another tool. Given the name of the … Read more
Maximum Protection Mode 1. No data loss 2. Redo has to be written to both Primary redo logs and standby redo logs (of atleast one standby database) before transaction commits 3. Primary database shuts down if redo stream is prevented to write at standby redo logs of atleast one standby database 4. Configure standby redo … Read more
It has been seen in cases where ORA-16401 and ORA-16055 reported in primary alert log when redo log switch is over frequently. So suggestion is to Increase the Size of the Online Redologs to reduce Redolog Switch Frequency. And this may also required to improve primary database performance. Please note if using Maximum Protection mode, … Read more
Database server crashed after memory on server used by inactive sessions The Following Example used to illustrate the scenario for User XX, please Review and modify whatever needed to confirm Automatic Kill of the Huge number of Inactive Sessions after a period of Idle Time . 1.CREATE THE PLAN 2.CREATE THE CONSUMER GROUPS 3.CREATE DIRECTIVES … Read more
We may need to find the database growth for different periods in the past. This Article provides the queries to find the monthly database growth OR Segments growth OR Specific Database Schema in the past days based on the AWR snapshots. There are different strategies for calculating the Monthly Growth of the Database : You … Read more
Below Are the differences b/w exp/imp vs Datapump 1. Datapump operates on a group of files called dump file sets. However, normal export operates on a single file. 2. Datapump access files in the server (using ORACLE directories). Traditional export can access files in client and server both (not using ORACLE directories). 3. Exports (exp/imp) … Read more