… resultset is huge, it eventually starts creating a temp table on disk. Now during those 300 second, other ‘innocuous’ queries which perform small insert or updates into completely different table (unrelated…
Post: 5 Percona Toolkit Tools for MySQL That Could Save Your Day: April 3 Webinar
March 22, 2013 By Leave a Comment
… times pt-archiver, to efficiently purge purge data from huge tables pt-table-checksum/pt-table-sync, to check if data on replicas is… data when performance problems happen randomly or are very short pt-online-schema-change, to run ALTER TABLE statements on large tables without… purge data from a huge table without putting too much load on your server How to check which tables are affected when someone…
Comment: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
The main performance win of TokuDB is indexes. If you add multiple multi-… huge win on selects. We used TokuDB in the past (versions 3.x and 4.x). It really shines on large tables…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… you can build the functionality you need and get the performance you need. Because I’ve built two such systems to… cost of repairing huge MyISAM tables and taking downtime, I would not use MyISAM for anything but read-only tables when things get… many cases. Especially on huge tables, it lets you scan portions of a table instead of the whole table if you a) choose…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… your concerns are at this stage. Is it the current performance, future performance, scalability, ability to recover from disasters? We also want… analysis, and also might show me things like huge tables that should be archived, tables that I should be aware of if I…. The changes Percona’s performance audits typically suggest can be really significant, and can completely change the performance profile and workload of…
Post: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
January 24, 2008 By 30 Comments
Really often in customers’ application we can see a huge tables with varchar/char fields, with small sets of possible values. … As you can see, ENUM and VARCHAR show close performance, while join performance degraded dramatically. Here is why: mysql> explain select SQL… join query performance is 30% lower. Also note the times themselves – traversing about same amount of rows full table scan performs about 25…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
I have been working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in the same way this blog post is aimed at a new optimizer enhancement Index Condition …
Comment: Using MMM to ALTER huge tables
April 4, 2008 By 11 Comments
[...] huge queries to huge tables. On the MySQL performance blog, Aurimas Mikalauskas walks us through using MMM to ALTER huge tables. He writes, “When it comes to changes that really require table to be rebuilt – [...]
Post: How adding another table to JOIN can improve performance ?
August 1, 2008 By 12 Comments
… require rather serious application changes and also can result in huge IN lists and suboptimal execution for large ranges. Lets take… join with day list table. So we finally managed to get better performance by joining data to yet another table though why it… fact perform much better than original one. In the real queries you can use table with ids just as we had table of…
Post: How innodb_open_files affects performance
November 18, 2009 By 4 Comments
Recently I looked at table_cache sizing which showed larger table cache does not always provides the best performance. So I decided to… if you create Innodb tables you better store some data in them otherwise there will be a huge waste of space. I… verify this I tried doing “open table” test for only 10K out of 100K tables – the performance was about the same, taking 1sec…
