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Displaying posts with tag: MySQL Administration (reset)
[Solved] MySQL User Operation - ERROR 1396 (HY000): Operation CREATE / DROP USER failed for 'user'@'host'

Error Message: ERROR 1396 (HY000): Operation CREATE USER failed for 'admin'@'%'
Generic Error Message: Operation %s failed for %s
Error Scenario: Operation CREATE USER failed
Operation DROP USER failed

Reason: The reason for this error is, you are trying to do some user operation but the user does not exist on the MySQL system. Also, for drop user, the user details are stored somewhere in the system, even though, you have already dropped the user from MySQL server.
Resolution: Revoke all access granted to the user, drop the user, and run FLUSH PRIVILEGE command to remove the caches. Now create/drop/alter the user, it will work.
REVOKE ALL ON *.* FROM 'user'@'host'; DROP USER 'user'@'host'; FLUSH PRIVILEGES;
Grant Tables: The following tables will help you in identifying the user related informations (as of MySQL 5.7):

mysql.user: User accounts, global privileges, and other …

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MySQL Replication Notes


The MySQL Replication was my first project as a Database Administrator (DBA) and I have been working with Replication technologies for last few years and I am indebted to contribute my little part for development of this technology. MySQL supports different replication topologies, having better understanding of basic concepts will help you in building and managing various and complex topologies. I am writing here, some of the key points to taken care when you are building MySQL replication. I consider this post as a starting point for building a high performance and consistent MySQL servers.  Let me start with below key points Hardware. MySQL Server Version MySQL Server Configuration Primary Key Storage Engine I will update this post with relevant points, whenever I get time. I am trying to provide generic concepts and it will be applicable to all version of MySQL, however, some of the concepts are new and applicable to latest versions …

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How to find database and table size in MySQL?

As a Database Administrator(DBA), your job want you to know the most atomic details of databases in your server. It happens for me many times, my boss/ delivery manager asking me, what is the size of a specific database or specific table, in this kind of situation, producing the right data will help make right decision. From my experience, I understood, it is always better to say, I will give you data in few minutes, instead of producing the incorrect data, which I had been doing for a long time.

This post is about identifying the size of a database(s) or table(s).  The simple script, I have been using it for quite a long, if not wrong when I started my career as DBA. You could have probably seen this/similar script on other forums as well and there are many other methods too. I am reproducing this handy script here to get work done.







Size of a specific table: …

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