… might look at how it uses MySQL to identify potential causes. Is it working with large blobs… how much memory is being used by current MEMORY tables: mysql> select sum(data_length+index_…, bytes 128849002496 Free buffers 1 Database pages 8252672 Old database pages 3046376 Modified db pages 23419…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… seen just about everything people throw at databases Many people assume their application is difficult… any one of these factors (schema, queries, indexing) in isolation, because they are tightly bound …where you need to really know how to write queries and how EXPLAIN works. At Percona, we have…
Post: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
… private as I partially got them while working for MySQL. These thought base on my understanding…index sized in the release we tested it is hard to see how small indexes really are. [-] No “using index…writes to the database and probably some others. This would be very interesting to see how these …
Post: How to recover deleted rows from an InnoDB Tablespace
February 20, 2012 By 3 Comments
…backup or the backup restore process doesn’t work. How can I recover deleted rows? We’re …import them into the database. The time between the deletion of rows and the database stop is crucial… different indexes and types. mysql (information_schema) > select i.INDEX_ID, i.NAME FROM INNODB_SYS_INDEXES …
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
… we manage to reduce Key_reads, we might make the database server faster overall, and perhaps the query of interest will… that is large enough to hold your working set — the index blocks that are frequently used. How large is that? This is yet… an amount of memory based on how important those tables are to you, how big the indexes are on disk, and so on…
Post: How adding another table to JOIN can improve performance ?
August 1, 2008 By 12 Comments
…fewer tables (for the same database) you join the better performance … make sense but this is how it is. I also …still does not work. The trick however does work if you have… Using index *************************** 2. row *************************** id: 1 select_type: SIMPLE table: g type: index …
Post: Working with large data sets in MySQL
July 5, 2007 By 12 Comments
… gotchas you simply need to plan carefully how you’re going to alter your database because it takes a lot of time… them by adding indexes and got back to fix some more. For large data sets this does not work and you really need to have some playground with smaller data sets to play with different schema designs and index…
Post: MySQL performance on EC2/EBS versus RDS
August 4, 2011 By 10 Comments
…the inserts go into one partition, whose indexes fit in memory. The more elaborate …think about. The physical and logical database design influences greatly how much memory and disk resources…administration work with RDS; you outsource that to Amazon, and you just do the database administration work….
Post: Statistics of InnoDB tables and indexes available in xtrabackup
September 14, 2009 By 6 Comments
…database is more accurate than with online (although online is also supported, but you may have inexact results). Let’s see how it works. I have one table with size …XtraDB/InnoDB plugin – fast index creation. With this feature, InnoDB creates indexes by sort, so …
Post: How multiple disks can benefit for single client workload ?
April 26, 2008 By 4 Comments
…of one. Let us first look how single query is executed for …containing old row version (and possibly index pages you’re to modify) – even… first thing to consider – single client work load does not necessary means single…come from the striping – consider 100GB database which is stored on single disk….
