…full tables and in turn, load that data into and pollute the buffer pool. Note that … “backup” server. As noted by one of my colleagues (thanks Bill Karwin!), the cumbersome part …=’InnoDB’; EOF mysql -N -B <<'EOF' > import-ddl.sql SELECT CONCAT(‘ALTER TABLE `’, table_name, ‘` IMPORT TABLESPACE;’) AS…
Post: SQL Injection Questions Followup
July 26, 2012 By 2 Comments
…(“,”, array_fill(0, count($params), “?”)); $sql = “SELECT * FROM Bugs WHERE bug_id IN ($placeholders)”; $stmt = $pdo->prepare($sql); $stmt->execute($params); Radu M… in my code? This is a big topic. One simple answer is that you can try embedding a string-termination quote into…’d like to see some of the folks who attended my SQL Injection webinar when I present the popular Percona Training in…
Post: Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 5 Comments
… to arbitrarily transform one type of expression into a different, but compatible type for computational…is how many physical cores are connected to my bus, and because I chose to create … six branches are combined with this. — AGGREGATION SQL: SELECT `word`,`md5(word)`,SUM(`count(*)`) AS `count(*)` …
Post: Eventual Consistency in MySQL
November 18, 2011 By 8 Comments
…SQL | +————————————————————————————————————————————————————————+ | SELECT…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
… asked this question in comments to to my previous Shard-Query benchmark. Actually he … but actually the data. Every SQL statements breaks down into a relational algebra equation. In Algebra…) GROUP BY 1 ORDER BY NULL ) — AGGREGATION SQL: SELECT `origin_airport_id`, SUM(`count(*)`) AS `count(*)`,…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
…select flexviews.get_sql( -> flexviews.get_id(‘demo’,'dashboard_customer_sales’)) -> as ‘SQL‘ \G *************************** 1. row *************************** SQL: SELECT…
Post: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?
August 28, 2007 By 57 Comments
… better to run two separate queries. For my tests I’ve created following simple table: CREATE…root”); mysql_select_db(“test”); for ($i = 0; $i < 10000000; $i++) { $b = $i % 1000; mysql_query("INSERT INTO … long our COUNT query would take: mysql> SELECT SQL_NO_CACHE count(*) FROM count_test WHERE b =…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
…it into the…sql-common/my_time.c patching file sql/filesort.cc patching file sql/log.cc patching file sql/log_event.cc patching file sql/my…sql/sql_cache.cc patching file sql/sql_class.cc patching file sql/sql_class.h patching file sql/sql_parse.cc patching file sql/sql_select.cc patching file sql/sql…
Post: How to load large files safely into InnoDB with LOAD DATA INFILE
July 3, 2008 By 29 Comments
… purge them, so everything gets bloated and slow. Even simple SELECT queries might have to scan through lots of obsolete, but…_checks=0; set sql_log_bin=0; set unique_checks=0; load data local infile ‘infile.txt’ into table load_test fields…_checks=0; set sql_log_bin=0; set unique_checks=0; load data local infile ‘/tmp/my-fifo’ into table load_test fields…
Post: SELECT LOCK IN SHARE MODE and FOR UPDATE
August 6, 2006 By 51 Comments
…hints in MySQL and SQL Server. In MySQL/Innodb LOCK IN SHARE MODE and SELECT FOR UPDATE …required. What is missing in Innodb locking.? In my oppinion few rather important peices missing in …to complete. The best example would be INSERT INTO MyISAMTable SELECT * FROM INNODBTable; – A lot of shared …
