… created table with simple structure: mysql> show create table dt2 \G *************************** 1. row *************************** Table: dt2 Create Table: CREATE TABLE `dt2` ( `grp…. Different table structures (ie longer rows) also may affect results, not to mention tables with fragmented rows …
Post: Read Buffers, mmap, malloc and MySQL Performance
September 12, 2007 By 8 Comments
…profile (often together with strace) are great tools for MySQL Performance analyses. Too many people end tuning on… which can get expensive if virtual memory gets fragmented. A while ago I measured over 10 times…allocation – if you have small table or LIMIT 10 in full table scan query you well may not…
Post: Feature preview: Compact backups in Percona XtraBackup
January 29, 2013 By 11 Comments
… depends on how many indexes you have. For example for table order_line from tpcc benchmark, 100W. Original size: 3140M, Size… are created by sorting, that in general gives much less fragmented indexes, so it may result in an additional space saving… a full backup, and it will result in rebuilt de-fragmented indexes. I encourage you to try this feature and report…
Post: Make your file system error resilient
August 24, 2011 By 8 Comments
… block: 0 Block size: 4096 Fragment size: 4096 Reserved GDT blocks: 316 Blocks per group: 32768 Fragments per group: 32768 Inodes per… is probably not needed for partition you store MySQL data on, as chances are MySQL server is only one doing writes on… as needed, same as you would every so often check MySQL tables for corruption. To change those options you can run tune2fs…
Post: MySQL Users Conference - Innodb
May 9, 2007 By 6 Comments
… compressed tables, such as what is the average size pages were compressed to for data and for various indexes. How many “fragmented… happening to the same table. This was born same as bunch of others due to statement level MySQL Replication which among other… patch out where already which may come in MySQL 5.2 or even MySQL 5.1. I surely would like to see…
Post: MySQL 5.6: Improvements in the Nutshell
January 27, 2013 By 16 Comments
… January I have created the outline of improvements available in MySQL 5.6 which I thought was worth sharing to give… issues – Reduced Innodb Memory Fragmentation – Reduced Locking for Partitioned tables – Reduced Contention for LOCK_open – Support for multiple table_open_cache instances – Large…
Post: MySQL Binaries Percona build10
December 11, 2008 By 12 Comments
We made new binaries for MySQL 5.0.67 build 10 which include next fixes: We … | ON | | slow_query_log_file | /var/lib/mysql/slow_query.log | for compatibility with MySQL 5.1 and | userstat_running | OFF | to… check fragmentation of the last InnoDB scan | 1.0 | Percona | GPL | The names are Innodb_scan_* | | userstatsv2.patch | SHOW USER/TABLE/INDEX…
Post: Write contentions on the query cache
September 5, 2012 By 5 Comments
…I wanted to know more about how MySQL executes this query. So I … | 0.000004 | | checking permissions | 0.000004 | | Opening tables | 0.000021 | | System lock | 0.000009 | | init | …unit. But this could increase the fragmentation of the cache and degrade performance…
Post: Percona Server and XtraBackup weekly news, April 4th
April 4, 2011 By 1 Comment
… plans in light of developments in the market such as MySQL 5.5, MariaDB, Drizzle, etc. The short answer is that we’re very happy with Oracle’s GPL’ed MySQL releases as a baseline for Percona Server, we think that… creation” for ALTER TABLE and OPTIMIZE TABLE, which can make these blocking operations much faster and result in less fragmented indexes. He also…
Post: MySQL Architecture meeting at Google
April 24, 2008 By 2 Comments
… which are planned for MySQL 6.0 and beyond – abilities to intercept query execution or offloading query fragments and operations (sorting limit… lot have changed since that inside the MySQL and with forthcoming releases of MySQL 5.1 and 6.0 we’ll see… handicaps real flexibility power of storage engines to use different tables while being able to conveniently access data between them.
