We can change the snap_interval and retention period for the automatic awr snapshot collection, using modify_snapshot_settings function. The default settings for ‘interval’ and ‘retention’ are 60 minutes and 8 days . The dba_hist_wr_control table shows the AWR snapshot settings, namely the snapshot interval, the retention period and the top-x-sql collection threshold: AWR Snapshot Reports Oracle … Read more
During 19c Upgrade, Materialized view creation which is from a pre-built base table is showing COMPILATION ERROR without any specific error messages. Base table column had different precision then a pre-built materialized view table and it caused the COMPILATION_ERROR without specifying the correct error message. –> both these columns precision is different. it should be … Read more
After upgrading a database from 11.2.0.4 to 12.1.0.2, the following errors are reported executing a datapump import process: CAUSE The issue is because the COMPATIBLE parameter for the 12c importing database is still 11.2.0.4 (value before the upgrade). It was confirmed based on the information provided: 1. Version of the exporting database 12c (12.1.0.2.0), compatible … Read more
RAID stands for Redundant Array of Inexpensive Disks which was later interpreted to Redundant Array of Independent Disks. This technology is now used in almost all the IT organizations looking for data redundancy and better performance. It combines multiple available disks into 1 or more logical drive and gives you the ability to survive one … Read more
A checkpoint is an operation that Oracle performs to ensure data file consistency. When a checkpoint occurs, Oracle ensures all modified buffers are written from the data buffer to disk files. Frequent checkpoints decrease the time necessary for recovery should the database crash, but may decrease overall database performance. A checkpoint performs the following three … Read more
Sometimes you may need to kill the RMAN session which is hanging and does not respond. There are several ways to terminate an RMAN command in the middle of execution: 1. The preferred method is to press CTRL+C (or the equivalent “attention” key combination for your system) in the RMAN interface. This will also terminates … Read more
ARCHIVELOG mode is a mode that you can put the database in for creating a backup of all transactions that have occurred in the database so that you can recover to any point in time. NOARCHIVELOG mode is basically the absence of ARCHIVELOG mode and has the disadvantage of not being able to recover to … Read more
During the Creation of database via DBCA , SPFILE is created in the file location that we specify. This location can be an ASM disk group, cluster file system file, or a shared raw device. If we manually create your database, it is recommended that you create an SPFILE from a PFILE. All instances in … Read more
Sometimes the DBA requires to create the read-only user for a particular schemas.While creating the user,one should always keep in mind that the user should have minimum privileges. There is no any direct command to create the read-only user in oracle. Sometimes I find people grants “read any table ” privileges to create the read-only … Read more
Large objects (LOBs) LOBs can be a problem in data replication by virtue of their size and the ability to extract, transmit, and deliver the data from source to target. Tables containing LOB datatypes should be isolated from regular data to use a dedicated Extract, Data Pump, and Replicat process group to enhance throughput. It … Read more