Manual creation of SQL Profiles in Oracle Database

SQL Profiles are a powerful tool to improve performance of SQL queries in your Oracle Database. A SQL profile is a database object that contains auxiliary statistics specific to a SQL statement. Conceptually, a SQL profile is to a SQL statement what object-level statistics are to a table or index. SQL profiles are created when a DBA … Read more

Crontab : Blocking session

Blocking sessions in Oracle are sessions which holds an exclusive lock on an object and doesn’t release it before another sessions wants to update the same data. This will block the second session until the first session has completed its work. Grant 777 permission to session_lock_asrblg1.sh script for its execution. Find Locked Table Find Lock … Read more

How To Run SQL Tuning Advisor

When we run SQL tuning advisor against a SQL statement or sql_id, it provides tuning recommendations that can be used to improve performance. It might give suggestion to create few indexes or accepting a SQL profile. As we all know running a slow query is a major performance issue in the database also has the biggest challenge for DBA to resolve … Read more

MEB Backup & Restore in MySQL

MySQL Enterprise Backup provides enterprise-grade backup and recovery for MySQL. It delivers hot, online, non-blocking backups on multiple platforms including Linux, Windows, Mac & Solaris. MySQL supports the following backup types: Logical backup Logical backup outputs a database structure in a .sql file by generating the CREATE or INSERT statements. Later, this file can be … Read more

Unable to generate Listener Log in Prod RAC DB

Cause: Looks like ADR is having the issue. Solution: Added the below parameter in the both the nodes and restarted the listener DIAG_ADR_ENABLE_LISTENER=OFF There are 3 parameters associated with ADR: DIAG_ADR_ENABLED DIAG_SIGHANDLER_ENABLED DIAG_DDE_ENABLED As long as you don’t set “DIAG_ADR_ENABLED = OFF” … ADR will still be enabled for the other services. THIS LOG.XML NEED … Read more

Apache Cassandra Performance Tuning

What is Apache Cassandra? ▪ NoSQL database ▪ Schema-free ▪ Very fast ‘write’ ▪ Cassandra is designed to handle big data workloads across multiple nodes with no single point of failure ▪ Cassandra addresses the problem of failures by employing a peer-to-peer distributed system across homogeneous nodes where data is distributed among all nodes in … Read more

Cassandra import & export

Cassandra.csv file data: Create keyspace and create tables and then importing the data form local system to Cassandra: $./bin/nodetool status $./cqlsh 192.168.0.104 Below are copied csv data from local system: Now we will export data from Cassandra to local file system: