…table changelogs which are created by FlexCDC. The refresh algorithm computes changes in multiple… create incrementally refreshable views from SQL statements. It reads one or more “CREATE TABLE …tables used by the above view, as stored in the data dictionary: mysql> select * from flexviews.mview_table…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
Post: The Doom of Multiple Storage Engines
May 8, 2010 By 22 Comments
…”Selling Points” of MySQL is support for Multiple Storage engines, and from the glance view it is indeed…data from memory when it fits there. Optimizer and Execution Storage engines are not created …combination such as running multi-table update joining PBXT and Innodb tables. Operations Things like …
Post: Using Flexviews - part one, introduction to materialized views
March 23, 2011 By 2 Comments
…SQL statement. MySQL even includes a SQL statement that makes this perfectly clear: CREATE TABLE .. AS SELECT …result. It is not possible to create multiple different tables via CTAS and have them all be…the view from scratch. This is the less desirable method: During a complete refresh, the view …
Post: Data mart or data warehouse?
July 15, 2010 By 13 Comments
… it is very hard to create a dimensional model from a highly normalized database schema…. from the warehouse data. A different approach is to build a relational warehouse from multiple …tables and materialized views. These features make working with a star schema much easier than it may be on MySQL…
Post: Using VIEW to reduce number of tables used
September 28, 2007 By 12 Comments
…table header modification, which is costly. Of course if you can simply rewrite software to store multiple users per table…table which has user_id,id, title,body columns and create post123 as view: create view post123 as select id,title,body from…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
…result set” is a SET created by the output of…table from each node correspond logically to a records in a Flexviews materialized view delta table… work, due to the multiple levels of result set …MySQL storage nodes are supported. Amdahl’s law applies to the distributed processing. The results from…
Post: How much memory can MySQL use in the worst case?
February 12, 2009 By 17 Comments
… single query may cause multiple sort buffers to be … tables. The following query creates at least 2 temporary tables: select * from ( select * from (…will also create temp tables; the same applies to views …, 0 rows affected (2.34 sec) mysql> select get_lock(@a, 1); +—————–+ | get_lock(@a…
Post: Why Index could refuse to work ?
September 8, 2006 By 13 Comments
…from the glance view): mysql> explain select * from article where article_id=10; +—-+————-+———+——+—————+——+———+——+——-+————-+ | id | select_type | table… at article table: CREATE TABLE `article` ( `article_id` …there are multiple strings possible …
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…mysql tables in use 1, locked 0 MySQL thread id 8079, query id 728899 localhost root Sending data select sql_calc_found_rows * from…” stage – if it is multiple statement transaction. Innodb … written. Created pages is empty pages created in buffer …queries in queue 1 read views open inside InnoDB Main …
Post: Intro to OLAP
July 12, 2010 By 9 Comments
…views to automate that aggregation process. Comparing the performance of OLAP with and without aggregation over multiple MySQL…from the fact table to the dimension tables. A note about degenerate dimensions: Any values in the fact table… You can create multiple different hierarchies from a single …
