Justin’s A workaround for the performance problems of TEMPTABLE views post on mysqlperformanceblog.com reminded me of a solution I once saw on a customer’s site. The customer was using nested views structure, up to depth of some 8-9 views. There were a lot of aggregations along the way, and even the simplest query resulted with [...]
In a period of two weeks, I had two cases with the exact same symptoms. Database users were experiencing low responsiveness. DBAs were seeing locks occurring on seemingly normal tables. In particular, looking at Innotop, it seemed that INSERTs were causing the locks. In both cases, tables were InnoDB. In both cases, there was a [...]
INSERT DELAYED may come in handy when using MyISAM tables. It may in particular be useful for log tables, where one is required to issue frequent INSERTs on one hand, but does not usually want or need to wait for DB response on the other hand. It may even offer some performance boost, by aggregating [...]
Following Restore one table from an ALL database dump and Restore a Single Table From mysqldump, I would like to add my own thoughts and comments on the subject. I also wish to note performance issues with the two suggested solutions, and offer improvements. Problem relevance While the problem is interesting, I just want to [...]
mycheckpoint (see announcement) allows for both graph presentation and quick SQL access to monitored & analyzed data. I’d like to show the power of combining them both. InnoDB performance Taking a look at one of the most important InnoDB metrics: the read hit ratio (we could get the same graph by looking at the HTML [...]
Following Baron Schwartz’ post: How to calculate a good InnoDB log file size, which shows how to make an estimate for the InnoDB log file size, and based on SQL: querying for status difference over time, I’ve written a query to run on MySQL 5.1, which, upon sampling 60 seconds of status, estimates the InnoDB [...]
I first read High Performance MySQL, 2nd edition about a year ago, when it first came out. I since re-read a few pages on occasion. In my previous posts I’ve suggested ways to improve upon the common ranking solution. Very innovative stuff! Or… so I thought. I happened to browse through the book today, and [...]
I find myself converting more and more customers’ databases to InnoDB plugin. In one case, it was a last resort: disk space was running out, and plugin’s compression released 75% space; in another, a slow disk made for IO bottlenecks, and plugin’s improvements & compression alleviated the problem; in yet another, I used the above [...]
I’ve encountered the same problem twice for different customers, so I guess it’s worth a discussion. A common task for web applications is to find out the country/region of a user, based on her IP address, as can be detected in the HTTP request. Depending on the country of origin, the website can translate dates [...]
When working with InnoDB, you have two ways for managing the tablespace storage: Throw everything in one big file (optionally split). Have one file per table. I will discuss the advantages and disadvantages of the two options, and will strive to convince that innodb_file_per_table is preferable. A single tablespace Having everything in one big file [...]