Posted recently on the maria-developers mailing list, by Igor Babaev, Principal MariaDB developer at Monty Program is some interesting preliminary results for MariaDB 5.3.0 benchmarked against the DBT-3 benchmarking program.

DBT-3 is a benchmark to test a decision support workload, with a suite of business-oriented queries and concurrent data modifications.

Read Igor’s discoveries, which he ran on a laptop with 4 cores (multi-threaded = 8 cores in total), 8GB RAM and SSD on SuSE, and as Igor says, enjoy his numbers. It is a repeatable benchmark with all settings included. We’d like to see discussion continued on the mailing list!

Resources

In April of 2011, InnoDB team published the early access of NoSQL to InnoDB with memcached, plus several new features as part of MySQL 5.6.2 milestone release. This week, we announced additional early access to new InnoDB features for the community to test, and provide feedback.

There are two release packages from InnoDB team on MySQL Labs: InnoDB full-text search, and InnoDB new features.

InnoDB Full-Text Search

MySQL 5.5 makes InnoDB the default storage engine, so everyone can benefit from ACID-compliant transactions, referential integrity, crash recovery.  However, some users need InnoDB to have built-in full-text search, similar …

Note: this article was originally published on http://blogs.innodb.com on July 27, 2011 by Vinay.

Long awaited InnoDB support for full-text index is available in InnoDB lab release. This post talks about the performance of InnoDB’s full-text support over MyISAM’s full-text support. (There are multiple aspect of full-text index performance, the most important ones are full-text index creation time and query execution time). We are not focusing on performance with “DML” (expect some simple insert on loaded data) and “other supported character sets” (numbers are based on latin1 char-set data).

Numbers are encouraging in terms of ‘create index’  time where InnoDB is comparable or faster than MyISAM. And query execution time are comparable with MyISAM. Over the time, we can expect optimization for query performance.

Please refer  …

Long awaited InnoDB support for full-text index is available in InnoDB lab release. This post talks about the performance of InnoDB’s full-text support over MyISAM’s full-text support. (There are multiple aspect of full-text index performance, the most important ones are full-text index creation time and query execution time). We are not focusing on performance with “DML” (expect some simple insert on loaded data) and “other supported character sets” (numbers are based on latin1 char-set data).

Numbers are encouraging in terms of ‘create index’  time where InnoDB is comparable or faster than MyISAM. And query execution time are comparable with MyISAM. Over the time, we can expect optimization for query performance.

Please refer  “Overview and Getting Started with InnoDB FTS” , …

Introduction
InnoDB has had the thread concurrency management code for some years now. Most will be familiar with the three configuration variables associated with this feature:

1. innodb_thread_concurrency
2. innodb_concurrency_tickets
3. innodb_thread_sleep_delay

The problem with the existing code is that the queueing overhead becomes too much and negatively impacts performance, especially as the number of user threads goes up. The queueing code uses the os_event_t …

Introduction

The InnoDB  UNDO entries reside in a special system table called the UNDO log. This log is made up of several segments. These segments are called rollback segments. A segment in InnoDB is similar to what a file would be in a file system,e.g., user tables and indexes are also stored as separate segments within the same tablespace,  only their format is different. In that sense there is nothing special about InnoDB UNDO logs. This feature allows storing of the UNDO log across several tablespaces.

Purpose

UNDO logs  contain the before image of modified records. There are two types of UNDO records, one for insert and another for updates. The insert UNDO records can be discarded on transaction rollback. The update records are used for rollback, MVCC and by purge. It is because of purge that we can’t just remove the UNDO log records  once the UNDO logs are …

Are you running an InnoDB installation with a many-gigabytes buffer pool(s)? Does it take too long before it goes back to speed after a restart? If yes, then the following will be interesting to you.

In the latest MySQL 5.6 Labs release we have implemented an InnoDB buffer pool(s) dump and load to solve this problem.

The contents of the InnoDB buffer pool(s) can be saved on disk before MySQL is shut down and then read in after a restart so that the warm up time is drastically shortened – the buffer pool(s) go to the state they were before the server restart! The time needed for that is roughly the time needed to read data from disk that is about the size of the buffer pool(s).

Lets dive straight into the commands to perform various dump/load operations:

The buffer pool(s) dump can be done at any time when MySQL is running by doing:

  mysql> SET innodb_buffer_pool_dump_now=ON;

This …

The primary database architectures—shared-disk and shared-nothing—each have their advantages. Shared-disk has functional advantages such as high-availability, elasticity, ease of set-up and maintenance, eliminates partitioning/sharding, eliminates master-slave, etc. The shared-nothing advantages are better performance and lower costs. What if you could offer a database that is a hybrid of the two; one that offers the advantages of both. This sounds too good to be true, but it is fact what ScaleDB has done.
The underlying architecture is shared-disk, but in many situations it can operate like shared-nothing. You see the problems with shared-disk arise from the messaging necessary to (a) ship data among nodes and storage; and (b) synchronize the nodes in the cluster. The trick is to move the messaging outside of the transaction so it doesn’t impact performance. The way to achieve that is to exploit locality. Let …

Some things are known to be just bad. GOTOs used to be one such thing (something I still use them, but only where appropriate, which isn't that many places). Maybe it is just so, that some things are useful, but not for everything, so maybe the issue is that they are used inappropriately. Or?

The OR condition is one such things in MySQL circles! Oh, you have an OR condition! That is going to be so slow! sort of. And the reason an OR is "slow" is that as MySQL will use only one index for each statement, only one "side" or the or condition can use an index. Or sometimes even worse, MySQL will consider using an index that is common to the two "sides" or is outside the OR conditition, despite that fact that there are perfectly fine, highly selective indexes on both sides of the OR condition.

If you ask me, this is not a fault with the OR condition but rather a problem with the MySQL optimizer. Why in heavens name can't a …

While looking at partitioning I recently made a mistake which I guess can happen to others. Often this is due to not fully reading the documentation or scanning it too quickly and misunderstanding what’s being said.

So this post is to complain about the MySQL partitioning syntax and to warn others who may easily make the same mistake without realising.

First we probably need to ask why we are partitioning a table in the first place. The main reasons for this are I think:

• to improve query performance
• to reduce individual .ibd file sizes for large tables (if using innodb_file_per_table)

In my case I wanted to do both. I had a several tables which store a large number of rows (batches of data) based on an incremental batch number. One of these tables was around 40 GB and had about 500,000,000 rows in it.  When processing data in this table often all the data from a particular batch …