Planet MySQL Planet MySQL: Meta Deutsch Español Français Italiano 日本語 Русский Português 中文
Showing entries 1 to 10 of 19 9 Older Entries

Displaying posts with tag: performance schema (reset)

Better Performance for JOINs Not Using Indexes
Employee_Team +1 Vote Up -0Vote Down

In some cases it is not possible to use an index to optimize a JOIN. This may for example happen when you query the Performance Schema. As a result these kind of queries can be very slow; however in MySQL 5.6 and later you can use a trick to improve the performance considerably.

As a working example in this post, I will use the schema_table_statistics view in the sys schema. Since the view involves the schema, I will create a reasonable large number of databases and tables for the test:

shell$ for ((i=0; i<100; i++)); do
>    echo "Database ${i}"
>    mysql -e "CREATE DATABASE db${i}"
>    for ((j=0; j<100; j++)); do
>        mysql -e "CREATE TABLE
  [Read more...]
5 great new features from Percona Cloud Tools for MySQL
+1 Vote Up -0Vote Down

It’s been three months since we announced anything for Percona Cloud Tools, not because we’ve been idle but because we’ve been so busy the time flew by!  Here’s the TL;DR to pique your interest:

  • EXPLAIN queries in real-time through the web app
  • Query Analytics for Performance Schema
  • Dashboards: customizable, shared groups of charts
  • Install and upgrade the agent with 1 command line
  • Unified UI: same time range, same host wherever you go

Percona Cloud Tools for MySQL is a hosted service providing access to query performance insights for all MySQL uses. After a brief setup, unlock new information about your database and how to improve your applications. There’s a lot more, but let’s just look at these five new

  [Read more...]
Using MySQL 5.6 Performance Schema in multi-tenant environments
+0 Vote Up -0Vote Down

Hosting a shared MySQL instance for your internal or external clients (“multi-tenant”) was always a challenge. Multi-tenants approach or a “schema-per-customer” approach is pretty common nowadays to host multiple clients on the same MySQL sever. One of issues of this approach, however, is the lack of visibility: it is hard to tell how many resources (queries, disk, cpu, etc) each user will use.

Percona Server contains userstats Google patch, which will allow you to get the resource utilization per user. The new MySQL 5.6 performance_schema has even more instrumentation which can give you a better visibility on per-user or

  [Read more...]
MySQL Performance Schema : Prepared Statements Instrumentation
Employee_Team +3 Vote Up -0Vote Down

MySQL 5.7.4 has a new Performance Schema feature, namely instrumentation for prepared statements. This instrumentation gives details of PREPARE and EXECUTE statistics for a prepared statement.

New Table
New table added to display run time statistics of Prepared Statements is named as prepared_statements_instances.

mysql> describe performance_schema.prepared_statements_instances;
+———————–+——————————————————
| Field                        | Type
+———————–+——————————————————
|




  [Read more...]
Getting started with Performance Schema and MySQL Workbench 6.1.2 Beta
Employee +2 Vote Up -0Vote Down

MySQL’s Performance schema is a relatively new tool for measuring performance and MySQL Workbecn 6.1.2 is the latest beta of that software. I have not had a lot of time to play with performance schema but now I am taking my first steps with the help of Workbench. Startup Workbench and you will find under the Navigator an item labeled Performance Schema Setup. Flip the toggle from OFF to ON and then start exploring.

InnoDB Buffer stats by Schema are show here — one of more than twenty pre-established metrics available.

Now you can run queries and see what the costs are, where the server is waiting, or what indexes remain unused. You

  [Read more...]
ps_helper and its migration to sys
Employee +1 Vote Up -0Vote Down

MySQL’s Performance Schema is an incredibly rich and versatile instrumentation engine, but apparently, with great power, comes increased complexity for the user to understand up front.

I think this is pretty natural:

  • The more flexibility you provide to the user on what to monitor (and this is one of the major goals of Performance Schema) – the more there is to twiddle from a configuration perspective.
  • The more data we provide in as generic a ways as possible – the more data there is.

Performance Schema is also only going to grow over time. There are many many missing bits of

  [Read more...]
Performance Schema implementation Internals: Registering instruments
Employee_Team +0 Vote Up -0Vote Down

This is the very first post in the series of Performance Schema Implementation Internals. This series is for MySQL Developers to understand implementation of Performance Schema. For user point of view of performance Schema, please refer to mysql documentation link : http://dev.mysql.com/doc/refman/5.7/en/performance-schema-quick-start.html

This post talks about the mechanism to register instruments in Performance Schema (referred as P_S from hereon) so that their statistics could be collected at runtime.

To understand this, lets first understand different instrument classes in P_S.

Instrument Classes in P_S:

An enum PFS_class_type is there to keep track of all possible classes of

  [Read more...]
MySQL Connect and Oracle Open World Presentations Online
Employee +3 Vote Up -0Vote Down

After a slight delay (travel and catching up with “real work”), I’ve now uploaded the talks that I gave at MySQL Connect and Oracle Open World.

They are available on my Presentations Page, and inline below for convenience. The “Introduction to MySQL Enterprise Monitor” talk was actually a full demo, but there are some screenshots of MEM 3.0 in there if you’re interested in seeing a high level picture of what it looks like now.

Thanks to all that attended my talks, I got a lot of good questions and feedback!

Performance Schema and ps_helper   [Read more...]
Thanks For Attending MySQL Connect
Employee_Team +2 Vote Up -0Vote Down

MySQL Connect 2013 was held this past Saturday through Monday, and I would like to extend a big thank you to everyone who attended my sessions, I talked to or otherwise took part in the conference.

I had two sessions as well as participated in a Birds of the Feather session with the Community and Support teams. The slides have been uploaded the the Content Catalog but they are not available for download from there yet. Until then you can download them from the the links below:

  [Read more...]
Troubleshooting High Memory Usage with MySQL on Windows
+2 Vote Up -0Vote Down

I was testing out the latest MySQL 5.6 on Windows (having used the auto-installer) and happened to notice my RAM usage (via Windows Task Manager) was reporting quite a high value, when I had very modest ram/buffer settings (should have been around 40M, but instead it was around 400M).

After double/triple-checking my settings to make sure I didn’t overlook something obvious, I searched the bugs database, and ran across bug #68287:

“High Memory Usage with MySQL 5.6.12 GA in ‘Development Machine’ mode”

Turns out, using the auto-installer set the value of table_definition_cache=1400, when the minimum value is 400. Reducing it to 400, and restarting MySQL immediately lowered the RAM usage, and is the “work-around”

  [Read more...]
Showing entries 1 to 10 of 19 9 Older Entries

Planet MySQL © 1995, 2014, Oracle Corporation and/or its affiliates   Legal Policies | Your Privacy Rights | Terms of Use

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.