…lot larger problems with MySQL 5.5 with addition of user variables, stored procedures, prepared … it uses MySQL to identify potential causes. Is it working with large blobs ? Using user variables ? … correspond to global memory allocation and will result in increased memory allocation until server is…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
…used by mysql client, so you might get a feel you can’t connect to the database at all (use mysql…result this means single run away select can effectively cause downtime if you use…
Post: Best kept MySQLDump Secret
March 23, 2012 By 11 Comments
…backup if you use this technique ? The problem comes from the fact how MySQL‘s Transactions… Transactions however apply to DATA which is stored in this table and so data …SET_CLIENT */; /*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */; /*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_…
Post: How Percona diagnoses MySQL server stalls
March 3, 2011 By 6 Comments
…determine normal versus abnormal, the higher quality your results will be. Find and change the following lines: … to look through it. It is stored in /root/collected/ by default. Use the “sift” tool to examine…many things that can cause a stall in MySQL, and they usually begin microscopically and get …
Post: MySQL Stored Procedures problems and use practices
June 12, 2007 By 21 Comments
… log will contain full stored procedure calls. On the other hand Stored Procedures Indeed can help to Improve MySQL Performance. For DBT2 benchmarks… back MySQL 5.0 was about 10% slower than 4.1 without stored procedures but was 20% faster if Stored Procedures are used. And… math if it can help you to avoid sending large result set back to the client as in this case server…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
… MySQL stored procedure API, called the SQL_API which is used to define the view. These stored …results mysql> select sum(total_lines) from dashboard_customer_sales ; +——————+ | sum(total_lines) | +——————+ | 155186550 | +——————+ 1 row in set (0.64 sec) mysql…
Post: Using Flexviews - part one, introduction to materialized views
March 23, 2011 By 2 Comments
…m giving a talk on it at the MySQL 2011 CE, and I figured I should … though. While both store results in a table, the MV represents the results of a SQL statement …uses those changes to compute the differences between the old results and the new results Delta application – How Flexviews uses…
Post: PHP Large result sets and summary tables.
July 6, 2007 By 8 Comments
…) like crazy. Why ? Because by default mysql_query uses mysql_store_result C library call and buffers all result set in the process memory. Not good… reach similar behavior. This call users underlying mysql_use_result API call which does not store all result set in memory but instead streams it…
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
… use it (bug 61587). We at Percona regularly use Memcheck for our development and upstream testing with useful results… at the same time. As a result, some of the stores might be lost, with the…-minor. Additionally, I’d consider backporting and using MySQL 5.5 atomic operation primitives with proper …
Post: MySQL Query Cache
July 27, 2006 By 69 Comments
… or use different case – these would be different queries for query cache. Only SELECT queries are cached SHOW commands or stored procedure… of them quite likely would not have change their result set but MySQL has no way to identify which one of them… option query_cache_limit was implemented which limits result set which can be stored in query cache. If you need larger queries…
