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10 Newer Entries Showing entries 61 to 70 of 905 10 Older Entries

Displaying posts with tag: Uncategorized (reset)

Using mysqldump and the MySQL binary log – a quick guide on how to backup and restore MySQL databases
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Be sure to check out my other posts on mysqldump:
Scripting Backups of MySQL with Perl via mysqldump
Splitting a MySQL Dump File Into Smaller Files Via Perl
– …


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MySQL Partitioning – A Quick Look at Partitioning – Separate Your Data for Faster Searches
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In MySQL, partitioning is a way to separate the data in one table into smaller “sub-tables” for better query performance and data management.

For example, let’s say that you have a database containing numerous accounting transactions. You could just store all of these transactions in one table, but you only need to keep seven year’s worth of data for tax purposes. Instead of placing all of the data in one table, and then deleting the old data from that table, you could split the table into partitions with each partition representing …

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Congratulations, Ubuntu!
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Today, we congratulate our friends at Ubuntu on a great new release, Ubuntu 14.04 LTS. As you can see in Mark Shuttleworth’s posting on Google+ from a few weeks back, MySQL has been cooperating closely with the Debian and Ubuntu communities to make sure that MySQL works very well on these platforms, and Ubuntu 14.04 […]

MySQL Enterprise Backup 3.10: Teasing compression.
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Ok, so I wanted to look into the new compression options of MEB 3.10.

And I would like to share my tests with you. Remember, they’re just this, tests, so please feel free to copy n paste and obtain your own results and conclusions, and should I say it, baselines, in order to compare future behaviour, on your own system.

An Oracle Linux 6.3 virtual machine with 3Gb RAM, 2 virtual threads, on a 1x quad core, windows laptop. Not pretty, but hey.

So, these tests are solely about backup. I’ll do restore when I get some *more* time.

 

First up, lets compare like with like, i.e. MEB …

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MySQL Enterprise Backup 3.10: Teasing compression.
Employee +0 Vote Up -0Vote Down

Ok, so I wanted to look into the new compression options of MEB 3.10.

And I would like to share my tests with you. Remember, they’re just this, tests, so please feel free to copy n paste and obtain your own results and conclusions, and should I say it, baselines, in order to compare future behaviour, on your own system.

An Oracle Linux 6.3 virtual machine with 3Gb RAM, 2 virtual threads, on a 1x quad core, windows laptop. Not pretty, but hey.

So, these tests are solely about backup. I’ll do restore when I get some *more* time.

 

First up, lets compare like with like, i.e. MEB …

  [Read more...]
A new dimension to MySQL query optimizations – part 2
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This is “A new dimension to MySQL query optimizations – part 2″. If you didn’t read part 1 already I suggest you skim through it before reading on.

To summarize, the problem at hand is this: Given a query with a join between two or more tables, the MySQL optimizer’s mission is to find the best combination of join order and access method so that the response time becomes as low as possible. The optimizer does this by calculating the cost of each combination and then picks the cheapest one.

Consider the following …

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Performance_schema success stories : replication SQL thread tuning
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A lot of customers have lagging slaves. It could be one of the top issues at support, due to the infamous row based replication without primary key issue :

Bug #53375 RBR + no PK => High load on slave (table scan/cpu) => slave failure

If you use binlog_format = statement or mixed ,  there are several ways of monitoring the SQL thread. The most ancient is the …

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MySQL Workbench 6.1.3 RC has been released
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The MySQL developer tools team announces 6.1.3 RC – the final release candidate for MySQL Workbench 6.1.

MySQL Workbench 6.1 is the upcoming major update for the official MySQL graphical development tool.
Introducing over 30 new features, this version has many significant enhancement focusing on real-time performance assessment and analysis from the SQL statement level to server internals and file IO. You’ll see this in additions to the SQL Editor as well as new dashboard visualization and reporting that takes advantage of MySQL Server 5.6 and 5.7 Performance Schema, and enhancements to the MySQL Explain Plans.


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innodb_flush_logs_on_trx_commit and Galera Cluster
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We deploy Galera Cluster (in MariaDB) for some clients, and innodb_flush_logs_on_trx_commit is one of the settings we’ve been playing with. The options according to the manual:

  • =0 don’t write or flush at commit, write and flush once per second
  • =1 write and flush at trx commit
  • =2 write log, but only flush once per second

The flush (fsync) refers to the mechanism the filesystem uses to try and guarantee that written data is actually on the physical medium/device and not just in a buffer (of course cached RAID controllers, SANs and other devices use some different logic …

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Performance_schema success stories : host summary tables
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This question was asked at support by a customer to solve a difficult issue.

How to identify a sporadic burst of queries coming from one of the hosts accessing the database ?

If there are hundreds of hosts, it can be challenging, especially if the queries are fast. No chance for them to get logged in the famous slow query log !

Here is the solution using the performance_schema in MySQL 5.6 :

SELECT
host,
SUM(essbben.count_star) AS total_statements,
format_time(SUM(essbben.sum_timer_wait)) AS total_latency,
format_time(SUM(essbben.sum_timer_wait) / SUM(count_star))
AS avg_latency
FROM …
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10 Newer Entries Showing entries 61 to 70 of 905 10 Older Entries

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