… you should have seen announcement by MySQL to develop pure PHP driver. If not – Here is FAQ . I’m to meet… to get a table below page output listing all the queries, their exec times and number of rows they are returned. So… for simple applications which may run query several times per page. I however would like to go further and have TTL…
Post: Read/Write Splitting with PHP Webinar Questions Followup
January 23, 2013 By 4 Comments
…gave a presentation on “Read/Write Splitting with PHP” for Percona Webinars. If you missed it, you … statement based, correct? A: Often that’s true, Row-Based Replication (RBR) can be faster than Statement-… using it in production. Even the official manual page for MySQL Proxy 0.8.2 still says: “…
Post: MySQL File System Fragmentation Benchmarks
March 21, 2008 By 28 Comments
….php $i 10000000; mysql -e’drop database test1′; mysql -e’create database test1′; done; tables: 1; total records: 10000000; write rows per….php $i 10000000; mysql -e’drop database test1′; mysql -e’create database test1′; done; tables: 1; total records: 10000000; write rows per… rows in the table which caused too much space allocated as single pages. I expect if we would use larger amount of rows…
Post: When EXPLAIN estimates can go wrong!
October 13, 2011 By 7 Comments
… I think innodb_stats_sample_pages really would have no effect on the “number of rows estimation”, because page sampling is used to… how it calculates the row estimates. This bug was tracked down to http://bugs.mysql.com/bug.php?id=53761 and was… of records on the leftmost and the rightmost page. Then it assumes all pages in between contain the average between the two…
Comment: Blob Storage in Innodb
February 16, 2010 By 13 Comments
… result of docs Bug#29042 (http://bugs.mysql.com/bug.php?id=29042) we did identify that the manual indeed implied… page. If it exceeds half a page, variable-length columns are chosen for external off-page storage until the row fits within half a page. For a column chosen for off-page storage, InnoDB stores…
Comment: Database problems in MySQL/PHP Applications
August 11, 2006 By 13 Comments
…you would have beautiful page > rendering as well as much more queries per page which will make > … optimizer to use the indexes to join rows together, potentially preventing a table scan. The … however start > to crawl. > So developing you PHP applications use test database with reasonable > amount …
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
… 1. row *************************** Name: ontime_fact Engine: InnoDB Version: 10 Row_format: Compact Rows: 6697533 Avg_row_length: …(adjust to your number of nodes) php genconfig 20 > shards.ini Running the…-on-metadata=0 innodb-stats-sample-pages=256 innodb-stats-update-need-lock…
Post: Goal driven performance optimization
December 22, 2008 By Leave a Comment
…_time-utime)/wtime) lost_ratio from performance_log_081221 where page_type=’search’ and wtime>1; +———-+—————–+——————+——————+——————+——————+ | count(*) | avg(wtime) | cpu_ratio… row in set (2.29 sec) Why looking only at such pages is important ? This is because if you look at all pages… this case we could spend a lot of time optimizing PHP code but because it takes only 10% of response time…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
… is completed? HT: A query thread normally posts about 64 page read requests per a readahead. The InnoDB buffer is 256… only recently found and fixed: http://bugs.mysql.com/bug.php?id=29560 Concerning a switch to Oracle’s main database… PRIMARY KEY, then InnoDB should have placed the rows in contiguous blocks of 64 pages == 1 MB. Then a full table scan…
Post: Caching could be the last thing you want to do
July 24, 2010 By 14 Comments
…subset of columns? Or do you extract many rows, only to use a subset? If so, you …about how many queries were required to generate each page? Or more specifically do you know that each one… – a quote from Justin’s slides on instrumentation-for-php. In terms of future-proofing design, many …
