… be used in the queries. This is wrong and hurts MySQL Performance. It is enough to create … and which need to be updated on update/insert delete. Duplicate keys are bad so once…redundant index will also be able to use longer index. Unlike with duplicate indexes, there are however cases when redundant…
Post: Rendundant Array of Inexpensive Servers
August 21, 2008 By 15 Comments
… every 2 years this is about a server a week which is bad and if you…redundant power supplies does not increase availability when it comes to hardware failures that much and so if you just look from this…You may also decide to keep more spare systems when you can use them to help capacity management, …
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…this on most operating systems (there are others, such as mpstat or dstat, that I may also elect to use… FROM clients)” which is a really bad query plan. After this I’ll look at SHOW INNODB …the mysql.* tables, running mk-duplicate-key-checker to find redundant indexes, and so on. As with settings…
Post: KISS KISS KISS
March 1, 2009 By 7 Comments
…ones. The examples I like to use is YouTube – they did …to 1 read ratio drop backs to one to one. This means you may not need a lot of slaves if your application allows use… is only related to the MySQL redundancy for very high quality… going down because of bad code or something unpredicted. Summary…
Post: Blob Storage in Innodb
February 9, 2010 By 13 Comments
… bad. I even seen a solution to store several smaller blobs or varchar fields which are when concatenated to get the real data. This is not exactly what happens 
With COMPACT and REDUNDANT row formats (used in before Innodb… to external storage. May be one day we’ll come to implementing this in XtraDB So BLOB storage was not very efficient in REDUNDANT…
Post: Redundant index is not always bad
August 28, 2007 By 7 Comments
About year ago Peter wrote about redundant indexes and mentioned sometimes it is good to leave two indexes, even one is first… columns In the benchmark for this query we have 10 queries per sec. Usuall technique we use for such queries is covering…. (This is for MyISAM, for InnoDB difference will be less. MyISAM uses key-compression for VARCHAR columns, so makes things worse). So to…
Post: MySQL Replication vs DRBD Battles
April 28, 2008 By 12 Comments
…transactional log reply is likely to take much longer than that. This is very bad property of DRBD – …this aspect however DRBD goes on par with MySQL Statement Based Replication – it is also well too easy to use… out where which would offer you full redundancy use of both nodes at least for reads …
Comment: Why you don't want to shard.
August 6, 2009 By 33 Comments
… not necessarily mean having no redundancy.”, I couldnt agree more, but this isnt specific to either centralised database or to shards. Having 4 database… failure. Again, this is a design level problem. Using sharding as a tool doesnt prohibit you from designing a redundant, fault tollerant infrastructure… of this, it actually looks more like RAID10 rather than RAID0. Of course, this can add complexity, but it doesnt need to be badly…
Comment: FlashCache: tpcc workload with FusionIO card as cache
June 8, 2010 By 20 Comments
…it turned into serious corruption or total data loss. This is where the Intel and other drives are a…of writes to each cell), free LEB’s, and other important data so we can predict any bad behavior …two cards with no redundancy in the system, we used a percentage of the money we saved to just buy more…
Comment: Finding your MySQL High-Availability solution – The questions
October 17, 2009 By 36 Comments
…in a bad way and causes the server to lose 99% of it’s performance this is much more difficult to …. Corrupt data is a reality unless your using something like ZFS to prevent if from ever happening. With …reliance on the SAN and it’s built in redundancy. You can count on anything failing in the …
