…Table works in MySQL >= 5.5.23. After the explanation I will share the results of benchmarks that I ran to compare…of contention as it is taken at a lot of different places, while the affect of…queries against a 20M rows table: sysbench –test=oltp –oltp-table-size=20000000 –mysql-table…
Post: DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
Post: Intro to OLAP
July 12, 2010 By 10 Comments
…differences between a data warehouse, and a data mart. Introduction to MDX queries and the kind of SQL which a ROLAP tool must generate to…to deal with millions or even billions of rows of…table which includes the two different…
Post: Using Flexviews - part one, introduction to materialized views
March 23, 2011 By 3 Comments
… of the query result. It is not possible to create multiple different tables…compared to computing the results. You can often generate multiple different blocks of…to the same point in time.  There are two different…of the database rows must be examined The rows examined are related to the rows…
Post: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
January 24, 2008 By 30 Comments
…different states (just happens to be data we had available for tests) Two important notes about this table before we get to…query performance is 30% lower. Also note the times themselves – traversing about same amount of rows full table…
Post: Derived Tables and Views Performance
August 31, 2006 By 16 Comments
…to each other but how do they compare in terms of performance ? Derived Tables in MySQL 5.0 seems to have different…to join two derived tables for example). One more thing to watch for is the fact derived table is going to be materialized even to… 1 row in set (0.03 sec) Same query using derived table…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
…to quantify what are the limits of different operations for different levels of…rows in contiguous blocks of 64 pages == 1 MB. Then a full table scan would be fast. Maybe the table…
Post: What do we optimize with mk-query-digest ?
December 15, 2009 By 2 Comments
…different MySQL user compared to the web site itself as it makes it easier to remove such queries from analyzes. What is Important to mention neither of…
Post: A case for MariaDB's Hash Joins
May 31, 2012 By Leave a Comment
…to support the possibility of existence of different join algorithms. So what does that mean to MariaDB/MySQL users right now with the state of…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…table, the number of these point primary key lookups will be depend on the number of rows…of difference when the workload is IO bound, the query time is decreased from ~11min to under a minute. The query…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
…of raw data, mostly in one table (lineorder). Each of the 13 queries were executed serially in a single connection I modified the queries to…compare the difference with innodb_old_blocks_time=0; mysql> set global innodb_old_blocks_time=0; Query OK, 0 rows…
