Search Results for: unique key on utf8

Store UUID in an optimized way

A few years ago Peter Zaitsev, in a post titled “To UUID or not to UUID,” wrote: “There is timestamp based part in UUID which has similar properties to auto_increment and which could be used to have values generated at same point in time physically local in BTREE index.” For this post I’ve rearranged the timestamp part […]

How to avoid hash collisions when using MySQL’s CRC32 function

Percona Toolkit’s  pt-table-checksum performs an online replication consistency check by executing checksum queries on the master, which produces different results on replicas that are inconsistent with the master – and the tool pt-table-sync synchronizes data efficiently between MySQL tables. The tools by default use the CRC32. Other good choices include MD5 and SHA1. If you have installed the FNV_64 user-defined function, pt-table-sync will […]

Q&A: Common (but deadly) MySQL Development Mistakes

On Wednesday I gave a presentation on “How to Avoid Common (but Deadly) MySQL Development Mistakes” for Percona MySQL Webinars. If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and especially to folks who asked the great questions. I answered as many as we had time […]

How to recover table structure from InnoDB dictionary

To recover a dropped or corrupt table with Percona Data Recovery Tool for InnoDB you need two things: media with records(ibdata1, *.ibd, disk image, etc.) and a table structure. Indeed, there is no information about the table structure in an InnoDB page. Normally we either recover the structure from .frm files or take it from […]

InnoDB Full-text Search in MySQL 5.6: Part 2, The Queries!

This is part 2 in a 3 part series. In part 1, we took a quick look at some initial configuration of InnoDB full-text search and discovered a little bit of quirky behavior; here, we are going to run some queries and compare the result sets. Our hope is that the one of two things […]

InnoDB Full-text Search in MySQL 5.6 (part 1)

I’ve never been a very big fan of MyISAM; I would argue that in most situations, any possible advantages to using MyISAM are far outweighed by the potential disadvantages and the strengths of InnoDB. However, up until MySQL 5.6, MyISAM was the only storage engine with support for full-text search (FTS). And I’ve encountered many […]

Best kept MySQLDump Secret

Many people use mysqldump –single-transaction to get consistent backup for their Innodb tables without making database read only. In most cases it works, but did you know there are some cases when you can get table entirely missing from the backup if you use this technique ? The problem comes from the fact how MySQL’s […]

Percona Server 5.1.58-12.9

Percona is glad to announce the release of Percona Server 5.1.58-12.9 on August 12, 2011 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.58, including all the bug fixes in it, Percona Server 5.1.58-12.9 is now the current stable release in the 5.1 series. All of Percona’s software is open-source and free, all […]