Search Results for: primary key not used

To UUID or not to UUID ?

Brian recently posted an article comparing UUID and auto_increment primary keys, basically advertising to use UUID instead of primary keys. I wanted to clarify this a bit as I’ve seen it being problems in so many cases. First lets look at the benchmark – we do not have full schema specified in the article itself […]

To pack or not to pack – MyISAM Key compression

MyISAM storage engine has key compression which makes its indexes much smaller, allowing better fit in caches and so improving performance dramatically. Actually packed indexes not a bit longer rows is frequent reason of MyISAM performing better than Innodb. In this article I’ll get in a bit more details about packed keys and performance implications […]

Importing big tables with large indexes with Myloader MySQL tool

Mydumper is known as the faster (much faster) mysqldump alternative. So, if you take a logical backup you will choose Mydumper instead of mysqldump. But what about the restore? Well, who needs to restore a logical backup? It takes ages! Even with Myloader. But this could change just a bit if we are able to take […]

InnoDB crash recovery speed in MySQL 5.6

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 […]

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 […]

Percona XtraDB Cluster 5.6.21-25.8 is now available

Percona is glad to announce the new release of Percona XtraDB Cluster 5.6 on Novmeber 25th 2014. Binaries are available from downloads area or from our software repositories. We’re also happy to announce that Ubuntu 14.10 and CentOS 7 users can download, install, and upgrade Percona XtraDB Cluster 5.6 from Percona’s software repositories. Based on […]

Data inconsistencies on MySQL replicas: Beyond pt-table-checksum

Percona Toolkit’s pt-table-checksum is a great tool to find data inconsistencies between a MySQL master and its replicas. However it is sometimes not enough to know that there are inconsistencies and let pt-table-sync fix the issue: you may want to know which exact rows are different to identify the statements that created the inconsistency. This […]