… work with BigData effectively Justin Swanhart, our Senior MySQL Instructor, will continue the topic of BigData with a talk titled, “Conquering BigData with MySQL and… be held at Portland State University’s Smith Memorial Student Union, located at 1825 SW Broadway, Suite 327/8/9 Portland… work with MySQL, then this is an event you can’t afford to miss… 
So register now! Please also join the Portland MySQL Meetup…
Post: Percona MySQL University @Portland next Monday!
June 12, 2013 By Leave a Comment
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 23 Comments
… with existing MySQL data sets and queries. Another advantage is that it works with all MySQL storage…stage.TailNum, … from ontime_stage join dim_date using(FlightDate) join dim_airport origin on ontime_…clauses, subqueries in the FROM clause, UNION or UNION ALL clauses. If none of those features…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…variable_value,40) var56 from var55 left join var56 on var55.variable_name=var56… MySQL 5.6 adds a lot more optimizer switches which you can play with: mysql [localhost] {msandbox}…union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on 1 row in set (0.00 sec) mysql…
Post: How is join_buffer_size allocated?
July 5, 2010 By 9 Comments
… 14177 Fill join cache with packed records…join_buffer_size = 1 << 30; # 1GB select * from (select 1 union select 1) as x1 join (select 1 union select 1) as x2 join…join. If you execute this and nothing bad happens, you might be seeing this bug: http://bugs.mysql…
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
…wants to replace longish (25-30) indexed varchars with an additional bigint column containing the crc64, and…to join the two tables? A: The question in this case is how MySQL will execute the join. If…you will need to use something like Trick “Unionizing Order by” described in presentation. Q: what is…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
… as a materialized view over a union of all the already joined and aggregated data from all the nodes… resource which speaks SQL, but right now only MySQL storage nodes are supported. Amdahl’s law applies … such a plan for a simple query with aggregation, a JOIN, and a WHERE clause that uses an …
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… provides you with all the data points you need to attack the right query in the right way. But vanilla MySQL does…_trx_id: F00 # QC_Hit: No Full_scan: Yes Full_join: No Tmp_table: No Tmp_table_on_disk: No # Filesort… 2.5% 51 0.0039 1.00 0.00 SELECT UNION wp_pp_daily_summary wp_pp_hourly_summary wp_pp…
Post: ORDER BY ... LIMIT Performance Optimization
September 1, 2006 By 100 Comments
… be UNION workaround I already wrote about. So what if you have application which can perform search on many different columns, with… from join execution (replaced with constants) and so ORDER BY can be optimized even if it is done by second table: mysql> explain… BY with JOIN MySQL still will not be able to use it as Optimizer is not smart enough yet to detect such cases: mysql…
Post: Quickly finding unused indexes (and estimating their size)
December 5, 2012 By 2 Comments
… view of a UNION DISTINCT of those two tables: mysql> create … from information_schema.tables t join information_schema.statistics i using …big in this case with test data): mysql> select * from droppable_indexes; +————–+—————+—————————–+—————+ | table…
Post: How adding another table to JOIN can improve performance ?
August 1, 2008 By 12 Comments
… The one I’m speaking about comes from the issue with MySQL optimizer stopping using further index key parts as soon as… to this problem – using IN list instead of range or UNION which however require rather serious application changes and also can… by joining data to yet another table though why it does not work for multiple group remains question to check with MySQL Optimizer…
