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MySQL Community Server 5.5
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MySQL Community Server 5.5 (5.5.41 GA, published on Friday, 28 Nov 2014)

Oracle AVDF - Database Firewall Policies
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The successful deployment of a Database Firewall depends on an effective policy. Oracle AVDF includes preconfigured firewall policies as described in the Firewall Policy page in the Policy tab of the Audit Vault Server console.

These include policies that log all SQL statements, or log only unique SQL statements. In addition, the Database Firewall policy editor enables you to design your own policies quickly and efficiently.

Policy rules can depend on any combination of the SQL statement type, name of the database user, IP address of the database client, operating system user name, client program name, or any exceptions you …

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How to mess up your data using ONE command in MySQL/Galera.
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Or how wsrep_on can bring you to have a cluster with usless data.

This is a WARNING article, and it comes out after I have being working on define internal blueprint on how to perform DDL operation using RSU safely.

The fun, if fun we want to call it, comes as usual by the fact that I am a curious guy and I often do things my way and not always following the official instructions.

Anyhow, lets us go straight to the point and describe what can happen on ANY MySQL/Galera installation.

The environment

The test environment, MySQL/Galera (Percona PXC 5.6.20 version). …

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Full table scans and MySQL performance
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High season is coming, how do you make sure that MySQL will handle the increased load? Stress tests could help with that, but it’s not a good idea to run them in a production environment. In this case Select_scan, Select_full_join and other MySQL counters could quickly give you an idea of how many queries are not performing well and could cause a performance degradation as the load goes up.

Select_scan from SHOW GLOBAL STATUS indicates how many full table scans were done since last MySQL restart. Scanning the entire table is a resource intensive operation. It also …

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MySQL benchmarking: Know your baseline variance!
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Often enough I find MySQL benchmark results where the difference between results is 1% or even less and some conclusions are drawn. Now it is not that 1% is not important – especially when you’re developing the product you should care about those 1% improvements or regressions because they tend to add up. However with such a small difference it is very important to understand whenever this is for real or it is just the natural variance for your baseline test.

Take a look at this graph:
Click the image for a larger view)

 


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Nasty MySQL Replication Bugs that Affect Upgrade to 5.6
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There were two nasty MySQL replication bugs in two different 5.6 releases that would make it difficult to upgrade slaves to MySQL 5.6 while still connected to MySQL 5.5 master. The first of those bugs is MySQL bug 72610 which affects 5.6.19. Essentially this bug is triggered when the table structure on the slave is different from the table structure on the master which leads to unnecessarily large amount of RAM usage while replicating events that affect that table. The amount of RAM used would generally be more noticeable when the replicated transaction consists of …

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Write Yourself a Query Rewrite Plugin: Part 1
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With the query rewrite framework in the latest MySQL (Optimizer/InnoDB/Replication) labs release, you get the opportunity to author plugins that can rewrite queries. You can choose whether to rewrite the queries before and/or after parsing. Today I am going to walk you through how to write a pre-parse query rewrite plugin.

When would you want to use a pre-parse query rewrite plugin? The greatest benefit compared to post-parse rewrites — which I will cover in a separate post — is the efficiency, especially the lack of overhead for those queries that are …

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(More) Secure local passwords in MySQL 5.6 and up
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I log into a lot of different servers running MySQL and one of the first things I do is create a file in my home directory called ‘.my.cnf’ with my credentials to that local mysql instance:

[client]
user=root
password=secret

This means I don’t have to type my password in every time, nor am I tempted to include it on the command line with -p and get the dreaded (but completely accurate):

Warning: Using a password on the command line interface can be insecure.

MySQL 5.6 introduces a utility to make this …

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Alternatives for chunking bulk deletes in common_schema
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I've blogged about common_schema multiple times in the past, and it's a tool I use frequently. Last week I had a project to delete millions of rows from multiple rollup tables in a star schema. Since the tables are not partitioned I needed to use DELETE instead of DROP PARTITION, but I didn't want to delete millions of rows in a single transaction. My first instinct was to use …

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Announcing iiBench for MySQL in Java
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I just pushed the new Java based iiBench for MySQL (and Percona Server and MariaDB), the code and documentation are available now in the iibench-mysql Github repo. Pull request are welcome!

The history of iiBench goes back to the early days of Tokutek. Since "indexed insertion" is a strength of Fractal Tree indexes, the first iiBench was created …

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Showing entries 1 to 10 of 33492 10 Older Entries

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