… Quadruple Extra Large Instance …buffer pool is sized at 55G and I am using 4 buffer pool instances to reduce the contention caused by buffer…KEY (`transactionid`), KEY `marketsegment` (`price`,`customerid`), KEY `registersegment` (`cashregisterid`,`price`,`customerid`), KEY …growth in data-set on the …
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…small buffer pool and a very large number of rows from table2 that do not fit into the buffer…set to 6M. While the lowest query time for MariaDB 5.5 is when both the Hash Join and the Key…buffer_pool_reads and Innodb_data_read. We can see that with appropriately sized buffers less no. of Innodb_buffer…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…the buffer used for sorting the secondary key tuples. If the buffer size is large …buffer_pool_read_requests 1361851 1264739 1235472 1263290 1235781 Innodb_buffer_pool_reads 120548 102948 76882 102672 76832 Innodb_data…when buffer size is set large enough so that the index tuples fit in the buffer…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…buffers, such as innodb_buffer_size, key_buffer…large blobs ? …data_length+index_length) from information_schema.tables where engine=’memory’; +——————————-+ | sum(data_length+index_length) | +——————————-+ | 126984 | +——————————-+ 1 row in set…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
… with very large data sets are Buffers, Indexes and Joins. Buffers First thing you need to take into account is the fact – situation when data fits… ranges are scanned. There are also clustered keys in Innodb which combine index access with data access, saving you IO for completely…
Post: How much overhead is caused by on disk temporary tables
August 16, 2007 By 26 Comments
… set key buffer to 128M ? mysql> show global status like “key%”; +————————+———+ | Variable_name | Value | +————————+———+ | Key_blocks_not_flushed | 49361 | | Key_blocks_unused | 61201 | | Key_blocks_used | 49361 | | Key… | | Key_writes | 0 | +————————+———+ 7 rows in set (0.00 sec) As you can see we have no writes because data fits in key buffer. Note… performance for large data sets. So I decided to see what happens if I create a larger table – 4M rows. I sized key_buffer to…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 116 Comments
… more sensitive to buffer size compared to MyISAM. MyISAM may work kind of OK with default key_buffer_size even with large data set but it will crawl with default innodb_buffer_pool_size. Also Innodb buffer pool caches both data and…
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
… that both servers are identically tuned, and they have identical data, hardware, and workload. Even that doesn’t help, though. Problem… choose a key_buffer_size that is large enough to hold your working set — the index blocks that are frequently used. How large is that…. Raise the key_buffer_size until, when the buffer is full, Key_reads/Uptime reduces to a number you’re comfortable with. Set key_buffer_size really…
Post: Choosing innodb_buffer_pool_size
November 3, 2007 By 38 Comments
…Buffer Pool. This of course assumes your database is large so you need large buffer pool, if not – setting buffer… include MySQL buffers – query cache, key_buffer, mysql threads, temporary tables, per thread sort buffer which can … well have all data they need to proceed in the innodb buffer pool. I…
Post: Predicting how long data load would take
May 24, 2007 By 12 Comments
…buffer for them. Data Insert Order It is well known it is important to load data in primary key…Different storage engines have different settings which need to be set for optimal load speed. …_sort_buffer_size or key_buffer_size increase. Innodb typically needs large innodb_buffer_pool_size and large …
