June 20, 2013

Post: Implementing SchemaSpy in your MySQL environment

June 4, 2013 By 2 Comments

…Tables – Names, number of children, parents, count of columns, row counts, and comments — a great way for a high level overview of the table…to use the search feature of your browser to zero in on a particular table Constraints – lists the explicit Foreign Key constraints in the database…

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: ,

Post: Is Synchronous Replication right for your app?

May 14, 2013 By 18 Comments

… replication to all …how about maintaining the counter in memcache or redis and only flushing to the database periodically? if( $last_count…count = $last_count where achievement = ‘killed_troll’”; } change your schema In Example 2, above, how above moving the ‘joined’ column to the users_groups table…

Filed Under: MySQL, Percona Software, XtraDB Cluster Tagged With: , , , , , ,

Post: How To Test Your Upgrades - pt-upgrade

December 29, 2011 By 7 Comments

…counts, checksums, column count, query execution time including execution errors and warnings. So how…table from your production databases and tables. Use a separate account for testing – one that has read (i.e. SELECT) to all objects within the database… which tells in general how each fingerprint …

Filed Under: Insight for DBAs

Post: How to find MySQL queries worth optimizing ?

September 11, 2012 By 6 Comments

… be thinking in this case there is no database access happening at all – you would…tables but because the access type to the tables is “const” MySQL does not count it as access to two tables. In case of “real” access to… no” answer but rather helps to understand how much optimization is possible. For …

Filed Under: Insight for DBAs, MySQL

Post: Database access Optimization in Web Applications.

September 12, 2006 By 10 Comments

…to keep page look the same. Your task is simply to have this information delivered from the database most efficient way. Investigate how…database access. This applies to anything else – if you can avoid dynamic page generation at all and have server cache to… tbl to count amount of rows in the table (…

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Post: How fast is FLUSH TABLES WITH READ LOCK?

April 24, 2010 By 30 Comments

…to it, all other processes attempting to modify anything in the system are locked out. In theory, this might not seem so bad because after all…test | Query | 80 | Sending data | select count…to get a list of tables and columns in the current database for tab-completion. Note also that “Flushing tables…

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Post: Using any general purpose computer as a special purpose SIMD computer

May 16, 2011 By 5 Comments

…to show how to count the number of unique words, an how many times those words appear in…database system can not provide native parallelism, then performance will be poor. — SQL TO SEND TO…in set (0.00 sec) How to factor numbers create table…

Filed Under: MySQL

Post: How much memory Innodb locks really take ?

July 13, 2006 By 11 Comments

… row in set (0.27 sec) Table with rather small row size, containing 1638400 rows. Now lets lock all rows in this table and see how long does it take: mysql> begin; Query OK, 0 rows affected (0.00 sec) mysql> select count… on serious systems. Furtermore you would unlikely need or want to lock every row in your table/database which makes it even smaller problem.

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Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

February 26, 2013 By 1 Comment

…to find out how to make InnoDB FTS blazingly-fast, but simply to get a sense of how it works compared to…in our database…table by querying the various I_S.INNODB_FT_* tables. In particular, the INNODB_FT_CONFIG table is supposed to…

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , ,

Post: Why MySQL could be slow with large tables ?

June 9, 2006 By 141 Comments

…understand how much having data in memory …count(pad) | +————+ | 314008 | +————+ 1 row in set (29 min 53.01 sec) Also remember – not all…tables or perform complex queries finding relationships between objects. Normalized structure and a lot of joins is right way to design your database…

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