June 19, 2013

Post: Virident vCache vs. FlashCache: Part 2

May 17, 2013 By 3 Comments

…creating a vCache device with the default configuration, I started with a baseline HDD configuration for MySQL…from…mysql.sock ­­–mysql­-table­-engine=innodb ­­\ –oltp­-read­-only=off run The base MySQL configuration (configuration A) appears below: #####fixed innodb options innodb_file…

Filed Under: Benchmarks, Hardware and Storage, MySQL Tagged With: , , , , , , ,

Post: Recovering CREATE TABLE statement from .frm file

December 17, 2008 By 5 Comments

…5.1.30-community-log MySQL Community Server (GPL) Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the buffer. mysql> show create table… sec) mysql> select * from test_innodb; ERROR 2013 (HY000): Lost connection to MySQL server during query Recovering CREATE TABLE from .frm file for MyISAM Table We …

Filed Under: Insight for DBAs Tagged With: , ,

Post: MySQL 5.5 and MySQL 5.6 default variable values differences

February 21, 2013 By 8 Comments

… I’ve loaded the values from MySQL 5.5.30 and MySQL 5.6.10 to the different tables and ran the query: mysql [localhost] {msandbox} (test) > select… increased from 20 to 300 which I guess is one of the component of purging fine tuning in MySQL 5.6 innodb_file_per_table… when you have large number of tables or if you do many create/drop of innodb tables. optimizer_switch is the catch all…

Filed Under: Insight for DBAs, MySQL Tagged With: , , ,

Post: How to recover deleted rows from an InnoDB Tablespace

February 20, 2012 By 4 Comments

…tables and indexes (with their IDs) to the error log. mysql (employees) > CREATE TABLE innodb_table_monitor (id int) ENGINE=InnoDB; TABLE…

Filed Under: Insight for DBAs, MySQL

Post: CVE-2012-4414 strikes back in MySQL 5.5.29 (and what we're doing in Percona Server 5.5.29)

January 13, 2013 By 4 Comments

…5.5.29 (not yet released, but soon), I filed MySQL bug …5.5.28-29.3) is not affected. When the MariaDB team fixed CVE-2012-4414 they created…MySQL 5.5.29 (the Oracle provided binaries); it also failed. Basically, the following snippet from…2-1-1.data’ INTO TABLE `t“1` FIELDS TERMINATED BY ‘,’ ENCLOSED…

Filed Under: MySQL, Percona Software Tagged With: , ,

Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

February 26, 2013 By 1 Comment

…files in our database directory: -rw-rw—-. 1 mysql mysql 8632 Feb 20 15:54 dir_test_innodb.frm -rw-rw—-. 1 mysql mysql… of lettercase, you’ll get an error: mysql> CREATE TABLE dir_test_innodb4 (fts_doc_id BIGINT … settings for MySQL 5.6, and that was to change innodb_ft_min_token_size from the …

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , ,

Post: Connecting orphaned .ibd files

May 13, 2011 By 19 Comments

…files. A well known innodb_file_per_table option brings the second one. Tables and system areas are split into different files…from sakila database taken from some MySQL server. 0. Create empty InnoDB tablespace. 1. Create the table: mysql>CREATE TABLE…

Filed Under: MySQL

Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark

March 11, 2013 By 7 Comments

…_DIRECT is not used by default, the file system cache will give better read …stopped the MySQL 5.6 server, rebooted and verified again.  Same issue.  This was very different from MySQL 5.5.30,… tinyint, D_WeekDayFl tinyint ); DROP TABLE IF EXISTS lineorder; CREATE TABLE IF NOT EXISTS lineorder ( LO_…

Filed Under: MySQL Tagged With: , , , , ,

Post: Concatenating MyISAM files

November 19, 2012 By 5 Comments

… a file is the first byte of the first row… So we should be able to concatenate these files. Let’s see. mysql> create table… Database changed mysql> flush tables; Query OK, 0 rows affected (0.00 sec) mysql> select * from test_concat; +—-+ | id | +—-+ | 1 | | 2 | | 3 | | 4 | | 5 | | 6…

Filed Under: MySQL

Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit

November 24, 2011 By 2 Comments

…of a single word from memory is atomic …create.c:304) ==9090==    by 0x5A0789C: clone (clone.S:112) ==9090==  Location 0x6e26200 is 0 bytes inside global var “os_n_file…: get_schema_tables_result(JOIN*, enum_schema_table_state) (sql_…consider backporting and using MySQL 5.5 atomic operation primitives …

Filed Under: MySQL
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