One of the very frequent cases with performance problems with MySQL is what they happen every so often or certain times. Investigating them we find out what the cause is some batch jobs, reports and other non response time critical activities are overloading the system causing user experience to …
Comment: Moving Subtrees in Closure Table Hierarchies
May 2, 2012 By 7 Comments
… and then put it in an array or structure to loop over… Thanks, Annie.
Comment: What to tune in MySQL Server after installation
April 28, 2012 By 116 Comments
… is given below. Because there are several queries with while loop in my application. I request to all please help me…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… these optimizations. Batched Key Access Traditionally, MySQL always uses Nested Loop Join to join two or more tables. What this means… has only supported one join algorithm and that is Nested Loop Join. MariaDB has introduced a new join algorithm Hash Join… Hash Join as compared to Nested Loop Join, but for now it looks like Nested Loop Join is a much better general…
Comment: How to load large files safely into InnoDB with LOAD DATA INFILE
March 29, 2012 By 28 Comments
…,1) eq “\\”) { $line .= ; } } right at the beginning of the main loop. Then it works for me like a charm transferring the…). Also, rather then time’ing the mysql commands in the loop (second shell), I added –show-warnings to the command line…
Comment: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 27, 2012 By 20 Comments
… script that is constantly recloning a database now, in a loop, until that produces an InnoDB clone that is unrecoverable. I…
Comment: Introducing new type of benchmark
March 11, 2012 By 16 Comments
… one request of interest from one thread (usually in a loop to get an average of multiple executions) to get the…
Post: Infinite Replication Loop
October 10, 2011 By 2 Comments
… other master should also replicate events : Closer look: Infinite Replication Loop flow: If you have master-master with slaves or if… 1. How to identify an infinite replication loop ? When you have an infinite replication loop, the value of Seconds_behind_master will… master. Then wait until the passive master has executed the looping statements and pick up a position from SHOW MASTER STATUS…
Post: kernel_mutex problem. Or double throughput with single variable
December 2, 2011 By 17 Comments
… InnoDB starts the transaction, usually there is loop through ALL active transactions, and this loop is inside kernel_mutex. That is to… complex handling with spin loops, and there are two variables that affects mutex loops: innodb_sync_spin_loops and innodb_spin_wait_delay… 200. So there is final results with innodb_sync_spin_loops=200 for 1-1024 threads. Threads Throughput Throughput spin 200…
Comment: MySQL Stored Procedures problems and use practices
September 23, 2009 By 21 Comments
… name from a cursor loop in an update statement within said loop … in a trigger? OPEN cursor1; cursor_loop:LOOP FETCH cursor1 INTO l…_name; IF l_last_row_fetched=1 THEN LEAVE cursor_loop; END IF; UPDATE l_customer_name SET active = 1 WHERE customer_id = NEW.id; END LOOP cursor_loop; CLOSE cursor1; right now, when i run this, i get…
