…a database and generates a visual representation of it in a browser-displayable format. It lets you click through the hierarchy of database …is the only component of the tool. There are additional tabs: Tables – Names, number of children, parents, count of columns, row counts, and comments — a …
Post: Understanding the maximum number of columns in a MySQL table
April 8, 2013 By 5 Comments
… of polls: “What is the maximum number of columns in MySQL?” and “What is the minimum maximum number of…Back in 1979, Monty developed an in-house database named UNIREG. UNIREG was a text-based…count > 255) { my_message(ER_TOO_MANY_FIELDS, ER(ER_TOO_MANY_FIELDS), MYF(0)); DBUG_RETURN(1); } Which is, of…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…transactions for you. However, each autocommit is retried only the number of times specified by this variable (default is 1 retry). This…and only flushing to the database periodically? if( $last_count % 100 == 0 ) { $db->do( “UPDATE achievements SET count = $last_count where achievement = ‘killed_…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
…by Dimitri Kravchuk, we have received a large number of questions on why the benchmark results in both… as there is a non-trivial amount of updates to the database, all SELECT queries, even those …-threads=<1..1024> –test=oltp.lua –oltp_tables_count=8 –oltp-table-size=1000000 –rand-init=on…
Post: Percona Playback 0.6 for MySQL now available
April 9, 2013 By 1 Comment
… a server or database upgrade, change in my.cnf or schema change can affect the overall performance of your MySQL database server. Percona… to MySQL database servers. This feature introduces new –thread-pool-threads-count option, which can be used to specify the number of threads in…
Post: A rule of thumb for choosing column order in indexes
June 5, 2009 By 15 Comments
I wanted to share a little rule of thumb I sometimes use to decide which columns should come … database server with b-tree indexes. And there are a bunch of subtleties, but I will also ignore those for the sake of…
Post: A common problem when optimizing COUNT()
September 20, 2008 By 19 Comments
…COUNT() has two meanings. 1) count the number of rows 2) count the number of values. Sometimes, but not always, these are the same thing. COUNT(*) always counts the number of…
Post: Database access Optimization in Web Applications.
September 12, 2006 By 10 Comments
…. Just remember avoiding accessing database is the best way you can optimize database access. This applies … bad as running SELECT * FROM tbl to count amount of rows in the table (no joking)….number of columns) – this is not a good practice. However if you can reduce number of queries without a lot of…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… (such as IO read operations, the number of unique pages the query accessed, the length of time query waited for row locks, etc… the longest sum of run time, query ranked #1. The first row in the table above shows the Count of number of times this query… scan every time its run. The “Databases” section of the output also shows the name of the databases where this query was executed. Next…
Post: FaceBook Search, Search for social networks
August 12, 2007 By 4 Comments
… about searching user profiles and similar global objects not full database of posts and comments. At FaceBook scale it is easy to… on how search is implemented is counting number of results matched. FaceBook does not give you exact count unless it is small, showing something… FaceBook search I found number of features missing which would likely be great value for the users. This is of course content search…
