… in many cases. Whatever powerful and well tuned system you have if you put too heavy of concurrent load on it the response… having one process. This is true if you have system completely at your disposal. If you however need system to serve other users too you… process overloads system too much in this case throttling by having relatively short queries and introducing “sleeps” between them can be…
Post: Testing Fusion-io ioDrive2 Duo
May 10, 2012 By 12 Comments
… RAID-0 over two drives. I should note that to run this card you need to have an external power, by the same… may not have connector for external power, and for some you may need special “power kit”. So you need to make sure you have compatible…
Comment: How to load large files safely into InnoDB with LOAD DATA INFILE
May 9, 2012 By 28 Comments
…’ve confirmed it with a production setup that I have, with one slave having the data file in the same directory as master, and another without the file. This is a great strategy if you… slave(s) first and then run it on master (BEWARE: you should make sure to delete the INFILE from the slave’s…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… account locality of access, as you could be reading the same page multiple times. Consider if you have a small buffer pool and… explain how hash join algorithm works. Suppose you have two tables t1 and t2, that you wish to join together in an equi… at the start that BKA uses the MRR interface so you should also adjust/increase the size of the buffer that MRR…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
… like this – you have configured MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount… Statements ? memory tables ? In a lot of cases you have to guess and test, you can’t get information of how much memory… very small blocks, it should be just swapped out and when never needed again. So if you see swap file used space…
Comment: ext4 vs xfs on SSD
March 26, 2012 By 23 Comments
… a very short-sighted response. If you report the bug to RH, then a fix should become available at some point in the not-to-distant future, too (and perhaps you should pay for RHEL so you can… (use XFS) will prevail, and all that will have resulted is that you have a bunch of unhappy people left using ext4 because…
Comment: Should you move from MyISAM to Innodb ?
March 10, 2012 By 53 Comments
… crash is going to be a show stopper – you should not use MyISAM. If you have a huge number of concurrent writes and selects and query performance must be consistently fast in this use case – you should not use MyISAM. If none of the above apply, then you get the benefits of MyISAM…
Comment: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 26, 2012 By 20 Comments
… innodb data from the backup where Innodb fails to recover should be passed to your support provider for investigation. It might… – indeed there are known problems which are not handled if you have DDL however FLUSH TABLES WITH READ LOCK should prevent these.
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… work as optimally as you could think it works. Even though with general lock compatibility guidelines Read Lock should not conflict with… complete locking tables. This means if you have workload which includes some very long SELECT queries you can be potentially waiting for hours… lock in order to be set. As a workaround you can consider having scripts which would check for situation like above and…
Comment: Emulating global transaction ID with pt-heartbeat
April 24, 2012 By 6 Comments
… intermediate slaves to master and knowing that mysql does not have a way match the transactions as ‘global transactions id’.I… may be its a dumb idea but still throwing. if you have A——>B——->C and B crashed and captured information is… key errors for some time untill replication catches up.This should work fine in ‘row based replication’ correct ? because even pointing…
