… before it occurs. For example, if you see a large number of long-running queries in the output of … nodes in a MySQL Cluster installation are going to be talking to the same set of data nodes on the … get the server up with –skip-grant-tables and insert a few rows into an InnoDB table, but trying …
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
… percona-playback –mysql-host 127.0.0.1 –mysql-username playback –mysql-password PaSSwOrd –mysql-schema schema_name…_changes to prevent INSERTs, UPDATEs, and DELETEs from corrupting the data on the standby server…. This is necessary when running a large stream of queries. Benchmarks We benchmarked…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL …hundred. This really will open a large window where rows won’t be…INSERT INTO users_groups (user_id, group_id, joined) VALUES (100, 1, NOW()); Conclusion Choosing a system to replicate your data…
Post: Data mart or data warehouse?
July 15, 2010 By 14 Comments
… with and without aggregation over multiple MySQL storage engines at various data scales. What is a data warehouse? It turns out that this… even data from radio telescopes. This data is extracted from the source system(s) and then cleaned up and inserted into the data warehouse… “insert only”. Data is very likely never updated or deleted in these databases and they are expected to grow to very large sizes…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL…large_files_supportblogpercona.commanual large_page_sizeblogpercona.commanual large_pagesblogpercona.commanual last_insert…
Post: Predicting how long data load would take
May 24, 2007 By 14 Comments
… just way too many variables to consider especially while loading large schemas with a lot of different table structures. So which… to load data in MySQL you can use Multiple value insert (standard mysqldump output) or LOAD DATA INFILE (–tab mysqldump output). Generally LOAD DATA can…
Post: PHP Large result sets and summary tables.
July 6, 2007 By 8 Comments
… for massive growth. To make sure it handles large data sets as part of the process we work …are some limits as you can’t use mysql_num_rows() and mysql_data_seek() if you use this method … to run other queries, ie INSERTs and UPDATEs while you traverse with data. Not with unbuffered query because …
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… character data; try to make your rows fixed-length. One reason denormalization is important is that nested-loop joins on large data sets are very expensive. If MySQL supported sort-merge or hash joins, you… bypass the hard-to-scale database server for the initial insertion, because you can write CSV files with any programming language…
Post: Concatenating MyISAM files
November 19, 2012 By 5 Comments
Recently, I found myself involved in the migration of a large read-only InnoDB database to MyISAM (eventually packed). The only… data varchar(10); Query OK, 0 rows affected (0.02 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> insert into test_concat (id,data… sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> insert into test_concat_part (id,data) value (44,’todelete’),(4,’four’),(5,’five’),(6…
Post: Wow. My 6 year old MySQL Bug is finally fixed in MySQL 5.6
August 30, 2012 By 2 Comments
… of constant which is too large to the column instead of simply responding with empty set MySQL truncates the constant, performs the….34 sec) (Just some ranfom data. The only row we really need is with 2147483647) mysql> explain select count(*) from trunc where… more and more queries for values over 2bil as data continued to be inserted the system essentially collapsed in matter of hours…
