… join rows with table t2. This step is called the build step. After the hash table has been created, rows from table t2 are…, on the hash table we created earlier. This step is known as probe step. This join algorithm works best for highly selective queries…_buffer_size=4M & mrr_buffer_size=4M Created_tmp_disk_tables 0 0 0 0 0 0 Created_tmp_tables 1 1 1 1 1 1 Handler…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… disabled during these benchmark runs and that the disks are 4 5.4K disks in Software RAID5. Also note that the following… 5.5 w/ mrr_buffer_size=4M Created_tmp_disk_tables 1 1 1 1 1 Created_tmp_tables 1 1 1 1 1 Handler_mrr_init… that though both MariaDB and MySQL 5.6 are reporting high numbers for Innodb_rows_read, which is completely in line…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…Created_tmp_tables and Created_disk_tmp_tables, I’ll paste in mysql> show global variables like ‘%table_size%’; +———————+———–+ | Variable_name | Value | +———————+———–+ | max_heap_table_size | 268435456 | | tmp_table… reverse proxies, and high availability …
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 11 Comments
… DIMM {OUT OF SPEC} Other … # Disk Schedulers And Queue Size ############################# sda | [deadline] …_table_size = 64M thread_cache_size = 32 query_cache_size = 0 tmp_table…table but you did not set alignment options in xfs when creating… very similar, due to high concurrency response time in…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
…with MySQL still running. This will also automatically create a backup of the un-patched version … [qc_miss, full_scan, full_join, tmp_table, tmp_table_on_disk, filesort, filesort_on_disk] It allows you to filter … (1/log_slow_rate_limit) session. With high traffic coming to your database, the slow …
Comment: Database problems in MySQL/PHP Applications
November 6, 2006 By 12 Comments
… to # connect), the slave will create a master.info file, and any …disks #tmpdir = /tmp/ #log-update = /path-to-dedicated-directory/hostname tmpdir =/mysql_tmp/:/tmp/ # Uncomment the following if you are using BDB tables… RAM but beware of setting memory usage too high innodb_buffer_pool_size = 8000M …
Comment: Innodb Performance Optimization Basics
November 1, 2007 By 70 Comments
… is that if you set your buffers and settings too high and restart your mysql server, mysql wont instantly complain. What… of things like sort_merge_pass, full joins and tmp tables on disk so you could actually better find the queries causing slowdowns… intermediate developers/admins. Out of 801,000 tmp tables created, only 3,762 of those were on disk. It still bugs me that I…
