…to the following: SELECT key_column, pk_column FROM tbl WHERE key_column=x ORDER BY key_column… Now let’s move on to the benchmarks, to see the ….89G 1.53G Innodb_data_reads 120552 123872 100551…one MRR related variable introduced in MySQL 5.6 and MariaDB 5.5 Handler_mrr_init and another additional one…
Post: A case for MariaDB's Hash Joins
May 31, 2012 By Leave a Comment
… Table Structure Before moving on, let’s …to both MySQL 5.5 and MySQL 5.6. Another interesting thing to…to be joined from supplier table (left operand). Test Case D – Join a large data set (>1M rows) from one…to fetch the columns that are not part of the secondary key. Even though MySQL 5.6 uses MRR to…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So… optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take…
Comment: Air traffic queries in InfiniDB: early alpha
November 3, 2009 By 19 Comments
…to LOAD DATA INFILE. cpimport separators: I wanted to let you know that you can specify another separator value to…column depends on the column type and will vary from 8 MB to 128 MB in each allocation. We’re looking at ways to…
Post: How much overhead is caused by on disk temporary tables
August 16, 2007 By 26 Comments
…data which needs to be put to temporary tables – BLOB/TEXT columns…data to be read from the disk as nothing was written. So I filled bug on this. So what was performance mysql…another bug which means I will have to postpone this part of test to another…
Post: Faster Point In Time Recovery with LVM2 Snaphots and Binary Logs
February 23, 2012 By 3 Comments
…mysql> drop table salaries; — Ooops! Query OK, 0 rows affected (0.49 sec) mysql> alter table employees add column…data from the snapshot, under the hood restore is really a “rollback” to…
Comment: How to find wrong indexing with glance view
August 22, 2008 By 27 Comments
…Another tip, turn off caching on your testing environment MySQL…one column without putting much thought into how the data will be retrieved by the database. This allows you to…
Post: Small things are better
October 8, 2006 By 15 Comments
…to recover, smaller tables allow per table backup and recovery to happen faster. With MySQL and blocking ALTER TABLE there is yet another reason to…to use complicated scenarios to do simple things. Assume for example you need to add extra column to…move small pieces of data…
