…) ON DUPLICATE KEY UPDATE k=VALUES(k)+k; COMMIT; So this workload produces SEQUENTIAL inserts into Primary…? Obviously we can say that InnoDB is faster, but you should look into the steady … MyISAM Specific options key_buffer_size = 8M read_buffer_size = 1M read_rnd_buffer_size = 4M bulk_insert_buffer…
Post: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 3 Comments
… been committed at the current point in time, and thus should not be visible in the consistent read. For the REPEATABLE_READ isolation… factors, can be from few times to orders of magnitudes faster than a list scan. You may be curious if MySQL… following kinds of transactions: MySQL transactions started with START TRANSACTION READ ONLY MySQL transactions created by a non-locking SELECT statement…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
… with an empty transaction list when creating read views. However, the more general descriptors optimization… features even higher QPI speed (and thus, faster inter-process/node communication). Results: First of …:100M:autoextend innodb_flush_log_at_trx_commit = 2 innodb_flush_method = O_DIRECT innodb…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
… isolation level READ COMMITTED, then InnoDB normally does not lock the ‘gaps’, and it does not lock rows whose latest committed version does… with all pages in buffer pool it well may be faster to do 1 write than flush 10 non sequential pages… you have a battery-backed disk controller cache, then the commit returns in less than 100 microseconds. And if you do…
Post: New SpecJAppServer results at MySQL and Sun.
November 12, 2008 By Leave a Comment
… settings: transaction-isolation = READ-COMMITTED – this is indeed good setting for many workloads so unless you have repeatable reads requirement consider using this… have smaller sort buffer because allocating it will likely be faster. query_cache_size = 0M – query cache disabled. Not a big…
Post: Innodb performance gotcha w Larger queries.
August 28, 2009 By 7 Comments
… row statements. So with single statement MyISAM was about 10% faster, which is quite expected but with 1000 rows in the…
Post: Innodb Performance Optimization Basics
November 1, 2007 By 75 Comments
… are tiny but often faster than bigger ones. RAID10 works well for data storage and for read-mostly cases when you still… case increase it a bit. innodb_flush_log_at_trx_commit=2 If you’re not concern about ACID and can… application can run in READ-COMMITED isolation mode – if it does – set it to be default as transaction-isolation=READ-COMMITTED. This option has…
Post: MySQL 5.6: Improvements in the Nutshell
January 27, 2013 By 16 Comments
…Cache – Improved Adaptive Flushing – Page Cleaner/Separate Flush Thread – Group Commit for Binary Log – Fight Cache Coherence and False Sharing …Optimizer and Execution – Index Condition pushdown (ICP) – Multi-Range-Read (MRR) – Faster ORDER BY nidxcol LIMIT N – Persistent Statistics for Innodb – …
Post: MySQL Users Conference - Innodb
May 9, 2007 By 6 Comments
… it currently does which can be multiple orders of magnitude faster for large tables. There is fair number of questions about… to build them physically sorted so they should be much faster for IO Bound Index scans and large range scans. We… which limit concurrency in many cases can be removed for READ-COMMITED isolation mode which will start offering more performance benefits in…
Post: Percona XtraDB Cluster Feature 2: Multi-Master replication
January 19, 2012 By 22 Comments
… of writes. That is the write is either committed on all nodes or not committed at all. Let me draw some diagram… locally on the node, and only on COMMIT there is special handling. When you issue COMMIT, your transaction has to pass certification… master may apply event faster than a slave. And if you do read from the slave, you may read data, that has not…
