…IN_UNIQUE_CONSTRAINT = 1, REFERENCED_TABLE_SCHEMA = ‘ecommerce’, REFERENCED_TABLE_NAME = ‘Orders’, REFERENCED_COLUMN_NAME = ‘ID’; All that remains is to employ test.MY_KEY_COLUMN_USAGE in our query…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
… to find the images Amazon ID Name Arch Notesami-20b74949 shard-query…in the list of columns to show (click show/hide to change the columns) That the “public dns” field is selected SSH to…name-resolve sort-buffer-size=512K sql-mode=STRICT_TRANS_TABLES symbolic-links table-definition-cache=16384 table…
Post: Debugging problems with row based replication
May 6, 2010 By 10 Comments
…in particular that the server is trying to find is c1=1, but how can we find…SQL statements. I say semi-valid because the statements do not include column names. Column names are not included in…
Comment: Duplicate indexes and redundant indexes
January 19, 2012 By 38 Comments
…in a foreign key constraint +++Query++++ SELECT a.table_schema, a.table_name, a.constraint_name, a.constraint_type, convert(group_concat(DISTINCT b.column_name…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
…to handle this now. You can have the clicks column record the total, and the blue_clicks column record only blue clicks; to find…to write a little more complex queries, but that’s often justified by a large reduction in table…
Post: PROCEDURE ANALYSE
March 23, 2009 By 9 Comments
…to find the optimal data type for the column value – for example column…in most cases ? These and similar tasks are often done by bunch of SQL queries while really MySQL has a native feature to…
Post: A common problem when optimizing COUNT()
September 20, 2008 By 18 Comments
…to MySQL. The problem is when the COUNT() contains a column name, like this: select count(col1) from table; If you know your SQL…in your query. You meant to count the number of times the column‘s value is not null. This in… good place to learn about what it does. 90% of what you can find online is …
Post: What exactly is read_rnd_buffer_size
July 24, 2007 By 4 Comments
…in sorted order. If you use many queries…to – SQL or storage engine. Honestly as it had name very similar to read_buffer_size which is currently only used by MyISAM tables…in following conditions): Row pointers are stored in the sort_buffer, not the whole data selected Blob/Text columns…
