… it (ie Innodb) or do not support it (HEAP/MEMORY). Note in 5.0 you now have very nice value of… little sense to use it with Innodb tables for example. Note “flush” means “close file” in this case it does not… support large pages in general. Currently MyISAM and Innodb. Some SQL level items as Query Cache also could use this feature…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
….commanual sql_max_join_sizeblogpercona.commanual sql_modeblogpercona.commanual sql_notesblogpercona.commanual sql_quote_show_createblogpercona.commanual sql_safe_updatesblogpercona.commanual sql_select_limitblogpercona.commanual sql_slave_skip_counterblogpercona.commanual sql_warningsblogpercona…
Post: A note about Pythian
April 17, 2008 By 4 Comments
… is able to provide services for number of databases (Oracle, SQL Server, MySQL) while we provide services for number of full…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
… sql/sql_cache.cc patching file sql/sql_class.cc patching file sql/sql_class.h patching file sql/sql_parse.cc patching file sql/sql_select.cc patching file sql/sql… the filter just assign an empty string “” to this option. Note: you should put double quotes around the entire string of… would need to set this option to “microtime,innodbâ€. Note: You should put double quotes around the entire string of…
Post: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
January 24, 2008 By 30 Comments
…; Result time(mean): 0.082196 2) Results for VARCHAR: select SQL_NO_CACHE city from cities_varchar WHERE state=’Minnesota’ limit… difference often would be larger. It is also interesting to note performance of Innodb tables in this case: for VARCHAR it… the same, but join query performance is 30% lower. Also note the times themselves – traversing about same amount of rows full…
Post: A case for MariaDB's Hash Joins
May 31, 2012 By Leave a Comment
…=4 join_buffer_size=32M join_buffer_space_limit=32M Note that MariaDB includes a new variable ‘join_cache_level’, this… time taken to complete the above query: First thing to note is that I have scaled down the time taken by… with a selective WHERE clause on an indexed column The SQL used for this test together with its EXPLAIN output as…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… id 8079, query id 728899 localhost root Sending data select sql_calc_found_rows * from b limit 5 Trx read view… any of these variables is indication of IO bound workload. Note however – IO requests submited by threads executing requests are not… global lock to provide consitent information would cause significant overhead. Note: our book has an updated, more complete, more in-depth…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
… SELECT statements. Refresh type Aggregation Outer join All SQL functions Built using SQL Requires FlexCDC COMPLETE Y Y Y Y N INCREMENTAL…_top_customers) to list the top 10 customers nearly instantly. Note that every MV gets a special column `mview$pk` which… refresh views to the same transactional point in time. Also note that you can ‘COMPUTE’ or ‘APPLY’ changes to a particular…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
… distribute splitting and/or loading among multiple nodes as well. Note that in the demonstration each node will contain redundant, but…=’Contains the date information from the BTS ontime flight data. Note dates may not be in date_id order’; /*!40101 SET… command, called pivot_results cd shard-query/ $ ./run_query < queries.sql | tee raw |./pivot_results & [1] 12359 $ tail -f ./raw — Q1…
Post: Quick comparison of MyISAM, Infobright, and MonetDB
September 29, 2009 By 30 Comments
… first thing I tried doing was loading the data with SQL statements. I wanted to see how fast MyISAM vs. MonetDB… run, and averaged the next three together. Notes on Infobright A few miscellaneous notes: don’t forget that Infobright is not just… it to; it seemed pretty normal to a MySQL guy. Notes on MonetDB MonetDB was a bit different. I had to…
