…` (`AirlineID`,`Carrier`), KEY `Carrier` (`Carrier`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 COMMENT=’Contains information on flights, and what airline offered those flights…=InnoDB DEFAULT CHARSET=latin1 COMMENT=’Contains all avaialble data from 1988 to 2010′; mysql> use ontime1; Database changed mysql> show table status like… is selected in the list of columns to show (click show/hide to change the columns) That the “public dns” field is…
Post: How number of columns affects performance ?
September 28, 2009 By 12 Comments
… with 1 tinyint column and char(99) column and table with 100 tinyint columns. The former two…the code and would appreciate any developers comments but I guess for dynamic rows tables… +———–+ | 0 | +———–+ 1 row in set (3.26 sec) mysql [localhost] {msandbox} (test) > explain select max(t1…
Post: Tools and Techniques for Index Design Webinar Questions Followup
October 4, 2012 By 5 Comments
… are still relevant to current versions of MySQL. Q: How do the upcoming changes in MySQL 5.6 change the best practices… query groups by the same column as its sort column. You can optimize by adding the grouping column to your index, so all… in the grouping column. Then sorting it may be more likely to happen in memory. Q: Can you comment on the QUBE…
Post: Bug#12704861
November 20, 2011 By 1 Comment
… MySQL 5.1.60. I’ll repeat here the full documentation from the release notes: “InnoDB Storage Engine: Data from BLOB columns… if the server crashed at a precise moment when other columns were being updated in an InnoDB table. (Bug #12704861)” This…(nonfree=FALSE) to avoid leaking pages. row_build(): Correct a comment, and add a debug assertion that a record that contains…
Post: ALTER TABLE: Creating Index by Sort and Buffer Pool Size
June 27, 2012 By 4 Comments
…in terms of data and index size: mysql> show table status like “sbtest” \G *************************** 1. row …: latin1_swedish_ci Checksum: NULL Create_options: Comment: 1 row in set (0.00 sec)…significantly larger than amount of memory. Blue Columns in this case is the default configuration,…
Post: devops webinar - follow up Q&A
November 6, 2012 By 5 Comments
… wanted to thanks all the attendees and for the nice comments I got. As promised during the webinar, these are the… be easier. Q: When doing a migration that removes a column, moving the database first would make the old code break….0 1.1 1.2 Application use column col_a & col_b use column col_a no changes for that table Table…
Post: Using Flexviews - part two, change data capture
March 25, 2011 By 26 Comments
… appropriate changes. The file is well commented. The example settings file should work for most MySQL installations which allow connections as root…. You will notice that the source table only has two columns, but the changelog contains five. All change logs contain three additional metadata columns: dml_type, uow_id and fv$server_id. These columns represent the type of change…
Post: Realtime stats to pay attention to in Percona XtraDB Cluster and Galera
November 26, 2012 By 4 Comments
… not available currently. Let’s go through the columns. Cluster There are 4 columns in the cluster section, and it’s important… on several nodes. cmt This is the wsrep_local_state_comment — basically a plaintext word describing the state of the node… in. Our replication is performing well, because the Flow control columns are zeroes, but we do see some replication conflicts. Mostly…
Post: How to obtain the "LES" (Last Executed Statement) from an Optimized Core Dump?
September 9, 2012 By 9 Comments
…compilation time) First we inspect the mysql_execute_command frame: (gdb) frame 21 #21 0x00000000005a30af in mysql_execute_command (thd=thd@entry…_EXECUTION}, id = 0, query_strip_comments = {buffer = 0×0, length = 0, buffer_length = 0}, mark_used_columns = MARK_COLUMNS_READ, name = {str = 0×0, length…
Post: Full Text Search Webinar Questions Followup
August 24, 2012 By 5 Comments
… questions. Here are their questions and my answers. Adrian B. commented: Q: Would’ve been a good idea to retrieve the… index before declaring the `FTS_DOC_ID` primary key column properly, MySQL crashed with an out of memory fatal error, and the… to each other. Hernan S. commented on the blog post where I announced the webinar: We evaluated MySQL vs Solr. I was…
