About of Database Systems and Information Technologies
With PostgreSQL 15 version, logical replication became applicable by filtering on the tables by column and row. In this way, replication can be made in the desired columns and rows in the tables. Logical Replication wal_level=logical For logical replication, the wal_level parameter must be logical in the postgresql.conf file . By default, the value of wal_level is replica . The replica value provides the necessary wal files for streaming…
PostgreSQL version 15 was released and made available on October 13, 2022. PostgreSQL, the most advanced open source database, brought many new features with its 15th version. PostgreSQL 15 New Features Merge Command With the release of PostgreSQL 15, the Merge command was also made available. MERGE allows you to write a conditional SQL query that…
PostgreSQL has few feature for standby technology. I generally use streaming replication. This is very easy and confident. Streaming replication use a replication user for replication operations.Streaming replication allows a standby server to stay more up-to-date than is possible with file-based log shipping. The standby connects to the primary, which streams WAL records to the…
Unified Auditing is new audit feature came with Oracle 12c version. You have to do enable Unified Auditing to use after install database. Unified Auditing come as disabled by default. In previous releases of Oracle Database, there were separate audit trails for individual components: SYS.AUD$ for the database audit trail, SYS.FGA_LOG$ for fine-grained auditing, DVSYS.AUDIT_TRAIL$…
PostgreSQL has few feature for standby technology. I generally use streaming replication. This is very easy and confident. Streaming replication use a replication user for replication operations.Streaming replication allows a standby server to stay more up-to-date than is possible with file-based log shipping. The standby connects to the primary, which streams WAL records to the…
Sometimes, you may need to change redo log size to perform optimum size for performance. If you want to change redo log size of both standby side and primary side, you can use below commands. Current Status Of Redo Logs Primary Side SQL> select group#,sum(bytes/1024/1024)”Size in MB” from v$log group by group#; GROUP# Size in…
You can use flashback technology on standby side. If you want to make application test on database, you can use data guard as read write mode temporarily with flashback technology. You can create a restore point on standby side then you can do any transaction on standby side to test or any other purpose. After…
You can use the same steps to switchover for single data guard or multiple data guard configuration. Switchover operation will convert primary side to data guard and data guard to primary side. You have to control listeners whether it is running before switchover steps. Switchover Steps Primary Side SQL> alter system archive log current; SQL>…
Oracle 11g R2 database supports multi standby database structure up to 30 standby databases. We can use remote destinations for real time apply standby structures with todays network technologies. If your remote destination network is not good, you can use archivelog apply for remote destination with some delay. System informations are like below. System Informations…
Oracle 11g R2 database supports cascade standby database structure. If you are using RAC on primary side, your database version has to be least 11.2.0.2 to support cascade standby structure. You can use to reduce the load on your primary database with using cascade standby database structure. Primary database redo is written to the standby…