…a single new node. When you insert a subtree, you’re inserting multiple…table ‘TreePaths’ for update in FROM clause.” We can’t DELETE and SELECT from the same table in a single query in MySQL. But we can use MySQL’s multi-table…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 63 Comments
…in MySQL 4.0 Query Cache was designed to work with single…multiple MySQL Query Cache instances hashed by query hash. It would help to reduce complexity dramatically. Fast Invalidation Right now when you update the table…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
…a single base table. Knowing this, the query result set is treated as a materialized view over a…multiple levels of result set reduction. Finally, Shard-Query can automatically partition sets into subsets using…
Post: Data mart or data warehouse?
July 15, 2010 By 13 Comments
…a single dimension, while also maintaining the historical information about when each item was in…a star schema, the dimension tables in a data mart may be updated. In fact, there is a term for such a dimension – A…
Post: Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 6 Comments
…multiple times. mysql> load data infile ‘/tmp/words’ into table words (chars); Query…a little worse. This is not unexpected. Since Shard-Query must add at small amount of overhead, a single…
Post: Using MyISAM in production
June 17, 2006 By 35 Comments
…updates to the table. Even worse with bulk updates queries. You do not have to have a lot of such queries…tables (you can throw them away if it server crashes). You can use multiple of cache tables to avoid concurrency issues. Temporary tables used in…
Post: How adding another table to JOIN can improve performance ?
August 1, 2008 By 12 Comments
…table though why it does not work for multiple group remains question to check with MySQL Optimizer team 
UPDATE…In the real queries you can use table with ids just as we had table of days with a where clause instead of precreated table…
Comment: COUNT(*) vs COUNT(col)
April 11, 2007 By 41 Comments
…update transactions running). With multiple concurrent transactions, it is not really possible to cache the total number of rows in a table…makes clear, in most cases you need to have the proper indexes to ensure good performance of queries that use a…
Post: Making MySQL Replication Parallel
January 30, 2007 By 1 Comment
…single queries or transactions which do not have any overlap in terms of tables. For some users commit order for independent queries…multiple threads inside the server to share same transactional/lock context. In this case replication could accumulate number of queries execute them in…
Post: MySQL caching methods and tips
April 4, 2011 By 4 Comments
…query cache, since the rate of invalidation can not be controlled, and multiple cache entries may be invalidated by a single table…In order to make the miss path less expensive, use a layered approach to your caching. Cron jobs and summary tables can be used to make…
