…deployment has a massive data set size in relation to both the working set and the cache device size, the numbers are encouraging. …= 10240 max_allowed_packet = 16M binlog_cache_size = 16M max_heap_table_size = 64M sort_buffer_size = 4M join_buffer_size = 4M thread_cache_size = 1000 query_cache_size…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
… = 2048 max_allowed_packet = 16M binlog_cache_size = 16M max_heap_table_size = 64M sort_buffer_size = 4M join_buffer_size = 4M thread_cache_size = 1000 query_cache_size… defaults, as I understand from documentation TokuDB comes with good settings out-of-box, but I am ready to tune something…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…max_connectionsblogpercona.commanual max_delayed_threadsblogpercona.commanual max_error_countblogpercona.commanual max_heap_table_sizeblogpercona.commanual max_insert_delayed_threadsblogpercona.commanual max_join_sizeblogpercona.commanual max…
Post: How is join_buffer_size allocated?
July 5, 2010 By 9 Comments
…=0; /* End sequentel */ 14271 size=max(thd->variables.join_buff_size, cache->length); 14272 if (!(cache->buff=(uchar*) my_malloc(size,MYF(0)))) 14273 DBUG…_size is indeed very bad! And this leads me to an interesting possibility to run the server out of memory: set session join_buffer_size = 1 << 30; # 1GB select * from (select 1 union select 1) as x1 join (select 1 union…
Post: A case for MariaDB's Hash Joins
May 31, 2012 By Leave a Comment
… means that your effective join_buffer_size is not bigger than this value. Hence, the reason I have set join_buffer_space_limit=32M… Hash join is not ideal because you have a highly selective where clause that reduces the size of the joining data set. And hash join… it always uses the max values join algorithm. If join_cache_level=4 it always uses BNLH (hash join), if join_cache_level=8 it…
Comment: What to tune in MySQL Server after installation
October 8, 2012 By 118 Comments
…_size = 70 table_cache = 2048 table_open_cache = 512 [Buffers] join_buffer_size = 32M key_buffer_size = 640M myisam_sort_buffer_size = 64M sort_buffer_size = 4M read_rnd_buffer_size = 12M read_buffer_size = 4M… had 152 conections and this value is the max conection; when we have setting this parameters in 1000; so when I run…
Post: Review of MySQL 5.6 Defaults Changes
October 8, 2012 By 10 Comments
… smart. host_cache_size = 128 + 1 for each of the first 500 max_connections + 1 for every 20 max_connections over 500, capped… it could be needed as it is easy enough to set max_connections to over 5000 or use more than 5000 tables… able to deal with simple and complicated queries efficiently automatically. join_buffer_size = 256k The default is now double of what it…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
…. This set logic allows to multiple levels of reduction of the set, all in parallel. All joins, …a redundant node. Work on problems of any size. Set processing is massively parallel . In fact, it…TABLE IF EXISTS `aggregation_tmp#74082863` ; Edit *MIN/MAX are only distributable in INSERT-only workloads…
Post: Innodb row size limitation
April 7, 2011 By 12 Comments
…2. For the default page size of 16kb. this sets an ~8000 bytes limit on row size (8126 as reported … with 50 variable length columns, but if their max length is, say 50 bytes, you still have …added join complexity. However, if you have too much variable length columns and you can’t limit their size, …
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…6.10-linux-glibc2. | | MAX_ALLOWED_PACKET | 1048576 | 4194304 | | JOIN_BUFFER_SIZE | 131072 | 262144 | | TMPDIR |…=on,inde | +—————————————————+——————————————+——————————————+ 56 rows in set (0.05 sec) Lets go …
