June 19, 2013

Post: How to recover table structure from InnoDB dictionary

April 22, 2013 By 4 Comments

…’; +————–+—–+——–+——+——–+———+————–+——-+ | NAME | ID | N_COLS | TYPE | MIX_ID | MIX_LEN | CLUSTER_NAME | SPACE | … primary key fields are defined in CREATE TABLE statement …Use LOAD DATA INFILE constraints_parser generates mysql>LOAD DATA INFILE ‘/path…

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

Post: Data Recovery Toolkit for InnoDB Version 0.1 Released

November 26, 2007 By 6 Comments

… recover data even when processed InnoDB page has been reassigned to another table and/or was partially destroyed Supports all MySQL data types except BLOBs, SETs and BITs (will be implemented in next releases) Has really great set of data filters to define data ranges… table definitions yourself – you just need to add data filters and get your data back (well, in most of the cases) Results…

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Post: PROCEDURE ANALYSE

March 23, 2009 By 9 Comments

… review is to find the optimal data type for the column value – for example column is defined as INT but is it really… information for type column is maximum length which is really helpful in more cases than ENUM data type – maximum length of data actually stored often can tell us if we defined varchar field too wide…

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Post: High-Performance Click Analysis with MySQL

December 22, 2008 By 13 Comments

… out.  Define the types of queries you absolutely have to have, if possible, and note the ways and types of aggregation (by… want to build your aggregate tables to avoid joins. Watch Data Types Does your ad ID look like “8a4dabde-1c82-102c-ab13… big, every byte matters a lot.  Use the smallest data types you can, the simplest character sets you can, and watch…

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Post: Predicting how long data load would take

May 24, 2007 By 14 Comments

… to be set for optimal load speed. Depending on load type MyISAM may benefit from bulk_insert_tree_size increase myisam… value insert (standard mysqldump output) or LOAD DATA INFILE (–tab mysqldump output). Generally LOAD DATA can be optimized better and a bit… data itself (it defines the insertion order for the indexes) cause the challenges. If you have some particular history about loading similar data…

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Post: Knowing what pt-online-schema-change will do

November 1, 2012 By 1 Comment

…. Are the columns used correctly given their data types and definitions?  If a column is defined as “NOT NULL” but the tool does… should be safe because no triggers are created and no data is copied, so the table is empty. Although the tool… nothing seems odd or wrong.  And as always: backup your data and verify your backups before running pt-online-schema-change…

Filed Under: Insight for DBAs, Percona Software Tagged With:

Post: Flexviews - part 3 - improving query performance using materialized views

April 4, 2011 By 20 Comments

… methods are complete refresh and incremental refresh.   The view type/refresh method are interchangeable since a refresh method is selected…_API which is used to define the view. These stored procedures maintain the Flexviews data dictionary. The data dictionary is used by the… MV is stored internally, and represents the actual SQL that defines the view. A simple API call is made to associate…

Filed Under: Insight for DBAs, MySQL

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

February 26, 2013 By 1 Comment

…data, and then creating the FT index after the data is loaded. One obvious problem wih those instructions is that if you define…innodb; +———————-+———-+———-+———-+ | Table | Op | Msg_type | Msg_text | +———————-+———-+———-+———-+ | test.dir_…

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

March 11, 2013 By 7 Comments

…define an OLAP cube over a star schema, so they are popular for use with tools like Mondrian and also for data…Extra: Using where *************************** 2. row *************************** id: 1 select_type: SIMPLE table: lineorder type: ref possible_keys: LO_OrderDateKey key: LO_OrderDateKey key…

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Post: Pacemaker, please meet NDB Cluster or using Pacemaker/Heartbeat to start a NDB Cluster

May 19, 2010 By 10 Comments

… major outage, only one of the physical host where the data nodes are located comes up, the cluster will start. The… crm_config -n stonith-enabled -v false A last before defining resources, since the Heartbeat cluster is asymmetrical, meaning resources will…. The first things we need to define are the resources. A very handy resource type for us is the anything resource which…

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