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10 Newer Entries Showing entries 121 to 130 of 33899 10 Older Entries
MySQL versions performance comparison
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This blog aims to make a performance comparison between the different MySQL versions/editions and also comparing the differents MySQL forks such as Percona Server and MariaDB.  Indeed number of improvements as been done to innodb storage engine in the last MySQL versions. You can find below some of the performance improvements applied to InnoDB these last years (non exhaustive list):


MySQL 5.0

1. New compact storage format which can save up to 20% of the disk space required in previous MySQL/InnoDB versions.
2. Faster recovery from a failed or aborted ALTER TABLE.
3. Faster …


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OurSQL Episode 203: Scaling by Proxy Part 2
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PodcastsLearningPerformanceServer Tuning

In this episode we finish our series on MaxScale. Ear candy is about using MySQL and Galera for geographic replication, and at the Movies uses MySQL to build big data applications.

Beware of MySQL BLOB Corruption in Older Versions
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Does your dataset consist of InnoDB tables with large BLOB data such that the data is stored in external BLOB pages? Was the dataset created in MySQL version 5.1 and below and without using the InnoDB plugin, or with InnoDB plugin but with MySQL version earlier than 5.1.55? If the answer to both the questions are "YES" then it could very well be that you have a hidden corruption lying around in your dataset.

The post Beware of MySQL BLOB Corruption in Older Versions appeared first on ovais.tariq.

InnoDB crash recovery speed in MySQL 5.6
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It has been a while since I have looked at InnoDB crash recovery. A lot has change in the last few years – we have serious crash recovery performance improvements in MySQL 5.5 and MySQL 5.6, we have solid state drives raising as typical high performance IO subsystem and we also have the ability to set much larger log files and often have a much larger InnoDB Buffer Pool to work with.

First let me revisit the challenge with have with InnoDB configuration. For write-intensive workloads it is extremely important to size innodb_log_file_size for good performance, however the longer log file size you have the longer …

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MySQL Non-unique Indexes
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Somebody wanted to know how to find any non-unique indexes in information_schema of the MySQL. The query takes a session variable with the table name and returns the non-unique indexes by column names. It uses a correlated subquery to exclude the table constraints. A similar query lets you find unique indexes in MySQL. Both queries are in this post.

You set the session variable like this:

SET @sv_table_name := 'member_lab';

You can query the indexes result with the following query:

SELECT   s.table_name
,        s.index_name
, …
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What is a data type?
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I'd suppose that these statements are generally accepted:

A data type is a set of values.

So any value that belongs to that set is said to "have" or "belong to" that data type.

And any column which is defined as "of" that data type is going to contain values which have that data type, only.

For example a column C may be defined as of type INTEGER and will only contain values which belong to the set of integers.

And now for the exceptions, details, caveats, and errors.

What is synonymous with data type?

There are no synonyms; no other term should ever be used.

Not datatype. …

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Popular PHP Frameworks
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My students often ask me about popular PHP frameworks and MySQL approaches. I wish a PHP framework choice was as clear as a JavaScript framework, like AngularJS. Unfortunately, PHP frameworks aren’t that clear cut.

It seems that the most popular PHP frameworks are: Laravel (1st), Phalcon (2nd), and Symphony2 (3rd). I found the following graphic (from December 2013) that highlights popularity by percentage of the market (though I …

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Testing TokuDB’s Group Commit Algorithm Improvement
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The MySQL 5.6 Release has introduced some changes to how two phase commit works and is managed.  In particular, the commit phase of transactions to the binary log is now serialized and this behavior is something we identified fairly immediately.  We implement a group commit algorithm that needed to be altered so that TokuDB’s group commit to its recovery log would function effectively.

As part of our effort to verify the new Binary Log Group Commit functionality introduced in TokuDB 7.5.4 for Percona Server, we wanted to demonstrate the substantial increase in throughput scaling but also show the bottleneck caused by the …

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File carving methods for the MySQL DBA
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This is a long overdue blog post from London’s 44con Cyber Security conference back in September. A lot of old memories were brought to the front as it were; the one I’m going to cover in this blog post is: file carving.

So what is file carving? despite the terminology it’s not going to be a full roast dinner; unless you have an appetite for data which as you’re here I’m assuming you have.

The TL;DR of “what is file carving” is taking a target blob of data (often a multi GB / TB file) and reducing it in …

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December London MySQL Meetup
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The London MySQL Meetup Group hosted a new evening of MySQL related talks on December 11, this time in Canonical’s offices in the Blue Fin Building. Conveniently, it was timed so that it coincided with the Debian/Ubuntu packaging sprint, which I also attended.

We started with pizza, beer and small talk. Since this was my first meetup in London, there were lots …

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10 Newer Entries Showing entries 121 to 130 of 33899 10 Older Entries

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