… MySQL Server so it uses too small amount of memory it will likey perform suboptimally. If you however configure it so it consumes too much memory…, sorts, or need temporary tables as much as read_buffer_size, sort_buffer_size, read_rnd_buffer_size, tmp_table_size of memory might…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
…cases you can use result overload to make MySQL to consume so much memory so it will swap badly until … tables ? This can be offset by keeping myisam_sort_buffer_size low, but then performance would suffer. …is some global quotas so it can’t consume too much memory and also you can’t get all of …
Post: Wanted: Better memory profiling for MySQL
May 18, 2008 By 4 Comments
… find MySQL using too much memory. I would look at memory consumed by Innodb (it is often higher than innodb_buffer_pool_size) substract memory used… global resource management for MySQL, ie so I could restrict global temporary space for temporary tables or sort memory. Though I’m not…
Post: How much memory can MySQL use in the worst case?
February 12, 2009 By 17 Comments
… + (read_buffer_size + sort_buffer_size)*max_connections”. …stack, etc)? Those take memory too. The query cache …, 0 rows affected (2.34 sec) mysql> select get_lock(@a, 1); +—————–+ | get_lock(@…much, in my opinion. I think it’s far better to use a monitoring tool to watch the actual memory…
Post: MySQL EXPLAIN limits and errors.
July 24, 2006 By 6 Comments
…time In MySQL 5.0 with addition of greedy join the problem on looking at too many table…at which stage MySQL actually perform the sort or creates temporary table and so how much rows will be…memory temporary table. The other thing – since MySQL 4.1 sorting can be done with storing row data in the sort…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
…indexes. In fact even MySQL optimizer currently does not take it into account. For In memory workload index accesses …tables being small it would not slow things down too much. On other hand join of few large tables, …(the work is on a way) – MySQL can’t do hash join or sort merge join – it only can …
Post: What to tune in MySQL Server after installation
September 29, 2006 By 116 Comments
…for people to work as MySQL DBAs or be involved with MySQL Performance in some way…memory available. innodb_additional_mem_pool_size This one does not really affect performance too much, at least on OS with decent memory…reason to increase sort_buffer_size even if you have 64GB of memory to waste. …
Post: Should MySQL and Web Server share the same box ?
October 16, 2006 By 9 Comments
… decide ether to grow system in MySQL+Apache pairs or split MySQL And Web Server and place them … to web boxes memory failure, more likely you’ll have web server crashes and this sort of things. … being commodity these days you should not worry too much about it, unless you have each page generated …
Post: The two even more fundamental performance metrics
May 5, 2011 By 6 Comments
…in MySQL servers I work with when they’re running a simple read-mostly workload with most data in memory… like each other, but the completions will be sort of an echo of the arrivals, lagged by … and queueing happens. You can certainly obsess over this too much if you want to. On the other hand, …
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
…shared memory or other means. It’s cheap to create a connection to MySQL,…multicore servers. Mark Callaghan has done much more investigation of the pool of… I’m thinking of the lack of sort-merge joins or intra-query parallelism,… be a great OLTP web database too. MySQL replication is one of the core, …
