… Rows_sent: 1 Rows_examined: 655360 use test; SET timestamp=1325145746; select count(*) from auto_inc; Compare…row in the table above shows the Count of number of times this query was executed. Now let’s take a…create on-disk tmp tables every time its executed. Those are the two important things that…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
Post: MySQL-Memcached or NOSQL Tokyo Tyrant - part 1
October 15, 2009 By 16 Comments
… row to lookup up a row in another table based on a text field ( called email address ). Seems simple enough right? My two tables each contain 5M rows… up a very simple application that does what I have seen many clients do. Using this application I can then compare using… that row to lookup up a row in another table based on a text field ( called email address ). Seems simple enough right? My two tables each contain 5M rows…
Post: Using Flexviews - part two, change data capture
March 25, 2011 By 26 Comments
… query response times compared to accessing the non-aggregated data. Keeping MVs up-to-date (refreshing) is usually expensive. A change data… clear in a moment. Lets create a table, insert some rows, add a change log, delete rows and then insert some more of them: mysql> create table > test… three rows in the changelog, each representing one of the changes we made. You will notice that the source table only has two columns…
Post: DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
…table (which means that each table has its own tablespace), and you have to drop tables in a…Table implementation in Percona Server and DROP TABLE running in the background: So we can compare the graphs above, and see that there are dips in…
Post: New OLAP Wikistat benchmark: Introduction and call for feedbacks
January 28, 2010 By 16 Comments
… Schema Benchmark got a lot of interest (links…Compare engines in OLAP queries for planning, predicting growth, analyzing access patterns to wiki pages, draw trends. Compare engines in…rows / size 68152M So with two months of stats we have about 172GB of data with about 7 billion rows in fact table…
Post: Dynamic row format for MEMORY tables
September 6, 2011 By 5 Comments
…in a fixed-length block at the beginning of the row. If there were any variable-length column in…comparable due to slightly different number of rows inserted). In the second test we check if the dynamic row…tables are still used for temporary tables where the MEMORY tables with dynamic row…
Post: Using Flexviews - part one, introduction to materialized views
March 23, 2011 By 3 Comments
…in a table. Storing the results of a SQL statement into a table (even a temporary table…compared to computing the results. You can often generate multiple different blocks of content from the summarized data in…
Post: A micro-benchmark of stored routines in MySQL
August 16, 2009 By 7 Comments
… stored routines are in MySQL? I just ran a quick micro-benchmark to compare the speed of a stored function against a “roughly equivalent” subquery… is doing a table scan against the first query, and then executing the subquery for each row: mysql> explain select ….\G *************************** 1. row *************************** id… row in set (1.00 sec) If we explain it, we get output similar to the first table shown above, but the further two rows…
Post: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
January 24, 2008 By 30 Comments
…comparable directly, which is using integer value and having value mapping done on application level. So, first of all, a…table: c type: ref possible_keys: state key: state key_len: 1 ref: const rows: 225690 Extra: 2 rows in…
Post: ALTER TABLE: Creating Index by Sort and Buffer Pool Size
June 27, 2012 By 4 Comments
… Collation: latin1_swedish_ci Checksum: NULL Create_options: Comment: 1 row in set (0.00 sec) So we have about 3.7GB… expand_fast_index_creation=1 which builds table with primary key only when creating a table and when builds all indexes by sort… table with index (but is a bit too small to keep 2 copies) In this case we’ll see the following picture: Comparing these two…
