…size variable which allows you to limit size of MEMORY tables (the limit…size 7864319 Buffer pool size, bytes 128849002496 Free buffers 1 Database pages 8252672 Old database…
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
… really. You still have some tables in MyISAM format in “mysql” database. Plus HEAP/MEMORY tables are used for temporary tables which… tables. key_cache_age_threshold, key_cache_block_size, key_cache_division_limit Key Cache/Key Buffer replacement algorithm configuration variables. Obviously… be converted to on disk MyISAM table. It does not limit size of temporary table, neither it applies to tables created as…
Post: Limiting InnoDB Data Dictionary
February 11, 2009 By 13 Comments
… user oriented applications ( each user has dedicated database / table) it is disaster. For 100.000+ …included into our releases. To limit memory we introduce new variable innodb_dict_size_limit (in bytes). Some internals… used or not on MySQL level. We made it by checking MySQL table_cache. If table …
Post: Thoughts on MySQL Replication
July 7, 2006 By 18 Comments
… write up about using MySQL replication. The piece I find missing however is good description of warning about limits of this approach… many small-medium sized application. So in which case I would go using simple master slave replication ? – Small database size. Small meaning working…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 23 Comments
… improve the performance of queries against a MySQL database by distributing the work over multiple machines …then spread over six servers). Due to ICE limitations, the data was split before loading. The …performance of the following queries depends on the size of the date range: — Q8.0 SELECT dest…
Post: Researching your MySQL table sizes
March 17, 2008 By 28 Comments
…sizes so here it goes: Find total number of tables, rows, total data in index size for given MySQL…03 sec) Find biggest databases SELECT count(*)…LIMIT 10; +——–+——————–+——-+——-+——-+————+———+ | tables | table_schema | rows | data | idx | total_size | idxfrac …
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 141 Comments
… you’ve been reading enough database related forums, mailing lists or blogs you probably heard complains about MySQL being unable to handle…. If you started from in-memory data size and expect gradual performance decrease as database size grows you may be surprised by serve… should mention one more MySQL limitation which requires you to be extra careful working with large data sets. In MySQL single query runs…
Post: MySQL Crash Recovery
July 30, 2006 By 30 Comments
…which moves out all MyISAM tables out of MySQL database directory, checks them with MyISAMchk and moves them… I already wrote innodb_log_file_size and innodb_buffer_pool_size affect recovery time significantly as …data you might run select 1 from _table_ limit 1 for each table or any other statement -…
Post: Disaster: MySQL 5.5 Flushing
September 18, 2011 By 27 Comments
…, with 20 tables, 10,000,000 rows each. Total database size ~58GB. MySQL version: 5.5.16 Initial benchmark, which InnoDB configured for… it, it looks like: Basically there two stages: MySQL handles traffic and MySQL stuck. As you see stalls are very severe. There… 3025148100 or 2885M . Our summary log size is 3800M. InnoDB usually takes 75% mark as limit for “sync” stage ( 3800M * 0.75…
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
… to add another index. Q: We have a database that has about 400GB of indexes. The indexes … portions of them which are accessed frequently. The size of this “working set” can greatly depend on … in recent MySQL versions. However it is often too many. Instead of thinking about hard limit of indexes …
