… I had number of consulting projects with MySQL Query Cache being source of serious problems. …had massive amount of entries invalidated by some batch data load job. When you should worry ? If …hundreds of thousands queries being invalidated by single insert – this typically happens if you have rare …
Post: How many partitions can you have ?
December 5, 2009 By 19 Comments
… customer dealing with large MySQL data warehouse had the table which was had data merged into it with INSERT ON DUPLICATE KEY UPDATE statements… the batch. With 100 rows per batch and with 10000 rows per batch performance was not significantly different from 1000 rows per batch so…
Post: Using MyISAM in production
June 17, 2006 By 36 Comments
… it has to be one insert at the time. Happily inserts in MyISAM are rather fast …Just one is enough. Lock priorities. By default MySQL treats updates as higher priority operations. You …in batch processing and other means Exported data If you export data from OLTP system for example to perform data …
Comment: Edge-case behavior of INSERT...ODKU
October 31, 2012 By 6 Comments
…work I have been doing importing large amounts of data from a legacy schema to a completely re-… I was forced to find another method, and my batch insert / update method was it. Now I dont remember …highlights what would be a VERY good feature in MySQL. InsODKU would be much better implemented on the …
Post: Performance impact of complex queries
January 17, 2007 By 11 Comments
… underestimated is impact of MySQL Performance by complex queries on large data sets(ie some large aggregate queries) and batch jobs. It is… crunches large amount of data set wipes data from your normal working set from OS cache. Operation Systems and MySQL Itself employs various… time. If you delete things do DELETE … LIMIT 1000 and insert sleep 10; in between. By spreading load this way you…
Post: The performance effects of new patches
September 9, 2008 By 14 Comments
… MySQL C API and the server side prepared statement. The server has 8core CPU and RAID storage (RAID10 / 6 disks). The data… them. innodb_ibuf_contract_const is used during run a batch of insert buffer merge every 10 seconds, and innodb_ibuf_contract…/o capacity available, and it makes sense to do an insert buffer merge. */ innodb_buf_flush_const (default 10)Â * Usual…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
…Among other things compression for data pages and uncompressed index pages…area of optimization. I frequently see batch jobs killing server performance overtaking….cc in 5.1: static MYSQL_SYSVAR_ULONG(thread_concurrency, srv…INSERT with multiple values? We build up INSERTS on our clients and insert…
Post: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
…be done simply by changing meta data (it is not implemented in MySQL anyway though). Very interesting to… will see records in B which were modified/inserted after you started transaction. [-] Isolation Modes So …if you have long running transactions, for example batch jobs you may end up in trouble …
Comment: MySQL Partitioning - can save you or kill you
June 27, 2012 By 45 Comments
… in a combination of 2) are used for querying. Inserts are @ 800 inserts per second. Deletes are for records older than 60… batch (NOT good if it does not match insert rate) b) MERGE tables based on dates (sharding the main table) –> Queries and inserts… taking longer and inserts at the same time.. I know mysql should have no problem in handling this ampunt of data but am…
Post: How innodb_open_files affects performance
November 18, 2009 By 4 Comments
…open or closed. Furthermore besides MySQL table_cache Innodb maintains its own (called data dictionary) which keeps all…is about writes ? I tried again very simple test inserting the row in each of 100K tables. This…091118 18:47:44 InnoDB: Starting an apply batch of log records to the database… If …
