Shinguz's blog

Dumping BLOB's from the MySQL database

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A customer who is handling digital certificates had a problem with one of those. So we had to investigate.

Configuration of MySQL for Shared Hosting

If you ask around about shared hosting setups with MySQL everybody is frightened. In fact it looks like shared hosting is one of the most difficult setups you can get.

MySQL HA (high availability) Cluster cookbook

In the following article I have summarized some steps and hints to set-up a MySQL active/passive failover Cluster also sometimes called MySQL HA.

MySQL Performance Monitor with DRBD monitoring capabilities

The FromDual Performance Monitor for MySQL has now a new module for monitoring DRBD. Since more an more of our customers want to run MySQL High Availability solutions based on DRBD we have implemented this module.

Be careful when using SAN

Be careful when using SAN (Storage Area Networks) or similar shared storage solutions (and any other virtualization, consolidation or cloud solutions).

channel_failover.pl v0.02

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Starting and stopping, status and failover is possible now. Script basically works but should be made a bit more sophisticated still…

Closing Circle again and channel_failover script

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One thing I forgot to mention: We lost Cluster B. So we rebuilt Cluster B from Cluster A.

Query and traffic

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Hello Ky,

Yes. You got me right! I meant the query on ndb_binlog_index.

Careful using log_slave_updates

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Hi Krishna,

Why do you think we should be carful using log_slave_updates in circular replication set-up’s?

MySQL Cluster - Cluster circular replication with 2 replication channels

A few days ago I had to deal with MySQL Cluster replication. I did not do this for a while so I was prepared to expect some interesting surprises once again.

Same test for InnoDB

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I forgot to mention in the main post that I did these tests with 5.1.50.

How can I find what InnoDB version I am using?

In the old days everything was simpler. We had one maker of our favourite database management system and possibly the choice between different Storage Engines. Mostly the decision has to be taken between MyISAM and InnoDB. When you care about your data integrity you have chosen InnoDB.

Impact of indices on MySQL

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It is generally well known that indexes help a lot to speed up database queries (especially SELECT but also UPDATE and DELETE). It is less known, that indexes also have some disadvantages.

MySQL logon and logoff trigger for auditing

A while ago I did some research about MySQL audit functionality and logon a and logoff triggers. MySQL and MariaDB provide a logon trigger in the form of the init_connect variable but no logoff trigger where most of the work for auditing would be done. When we would have a logoff trigger we could track the login and possibility some activity of a user and implement auditing functionality.

Transactional memory resident tables with PBXT

Introduction

In his presentation about PBXT at the DOAG Conference 2010 Paul McCullagh was speaking about memory resident PBXT tables. They will be available in version 1.1 of the PBXT Storage Engine Plugin. Memory resident PBXT tables should have similar characteristics like normal MySQL MEMORY</span> tables</a>. But in addition to the MEMORY tables they are transactional and can handle BLOB</span> and TEXT attributes.

MyEnv for MySQL Multi-Database set-ups

This week I showed one of my customers our MyEnv. He was very interested in it and suggested to make it known in public. In fact MyEnv is available for download already several years…

How many warm MyISAM key blocks do you have?

When you are working with MyISAM [ 1 ] tables MySQL provides a feature called the Midpoint Insertion Strategy [ 2 ]. You can enable it with the parameter key_cache_division_limit [ 3 ].

Feature request at MySQL

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Bug #57532: Warm key blocks in MyISAM key_cache structure could be reported

Disadvantages of explicitly NOT using InnoDB Primary Keys?

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We recently had the case with one of our customers where we got externally generated random hash values (up to 70 bytes) and they were used as Primary Keys in InnoDB.

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