…you better store some data in them otherwise there will be a huge waste of space. I used MySQL … the same. As I mentioned Data Dictionary can take considerable amount of memory – In my case after reading …file size workload and even when crash happen (how many unflushed changes we had) Repeating test …
Post: How InnoDB handles REDO logging
February 3, 2011 By 19 Comments
…that is both optimal in terms of the amount of data logged whilst still … The log header stores information about the last checkpoint. The log is stored as …need to be applied. How does this affect response time? In order to keep…recently in his post MySQL 5.5.8 – in search of stability, as seen in…
Post: When should you store serialized objects in the database?
January 21, 2010 By 47 Comments
… Friendfeed posted a blog post explaining how they changed from storing data in MySQL columns to serializing data and just storing it inside TEXT/BLOB columns. It… this pattern tends to force you to read/write larger amounts of data at once. We’ve all been trained to know… clear loss in functionality. You can no longer easily perform aggregation functions on the data (MIN, MAX, AVG). You are storing the data in a…
Post: MySQL File System Fragmentation Benchmarks
March 21, 2008 By 28 Comments
… many files and seeing how this affects sequential read performance…amount of tables and does specified number of inserts going to random tables. I used default MySQL…Concurrent growth of many tables causes data fragmentation and affects table scan … fragmentation less if it stores different tables in…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…, I’ll paste in mysql> show global variables like ‘%table_size%’; +———————+———–+ | Variable_…in our book. Next I look at the data in… that approaches the amount of information a Percona…really know how to write queries and how EXPLAIN works…have a lot of stored procedures, which are…
Post: Evaluating IO subsystem performance for MySQL Needs
March 5, 2008 By 23 Comments
…how one can evaluate IO subsystem (Hard drive RAID or SAN) performance for MySQL… with significant amounts of memory (or reducing amount of usable memory…In any case especially playing with data size a bit you will well learn how… stored in controller cache and flushed to the disk in background – in …
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
…data from 1988 to 2010′; mysql> use ontime1; Database changed mysql…In general, a column store performs about 8x-10x better than a row store for queries which access a significant amount of data…
Post: MySQL Users Conference - Innodb
May 9, 2007 By 6 Comments
… store Compressed and Uncompressed versions of the page in the buffer pool in … data and for various indexes. How many “fragmented” pages do we have in … while limiting amount of pages which do not fit in compressed space….in MySQL 5.2 or even MySQL 5.1. I surely would like to see it sooner at least in…
Post: HandlerSocket on SSD
November 2, 2010 By 9 Comments
… Yoshinori announcement of HandlerSocket, the plugin to MySQL which open NOSQL way to access data stored in InnoDB. The published results are impressive, but… lookups queries to HandlerSocket. To measure how IO access affects throughput, I vary amount of rows accessed in script, on 150 mil rows…
Post: Air traffic queries in InfiniDB: early alpha
November 2, 2009 By 19 Comments
…data InfiniDB supports MySQL‘s LOAD DATA statement and it’s own colxml / cpimport utilities. As LOAD DATA…of data after load, until someone points me how to…that InfiniDB does not store counter of records, however …connect to mysqld anymore. In processes I see that…as it took good amount of time to deal…
