… temporary table to store an interim result set, and then use that to ultimately produce the result you want, that’s another technique… up matching rows in `title` by a secondary index. But the result was that it created a temporary table to count the movies… scanning more rows. But by avoiding the temporary table, and making lookups to the `kind_types` table by primary key, the result was…
Comment: Derived Tables and Views Performance
May 21, 2013 By 16 Comments
…-mysql-and-php-prodcuts-and-cart.html create dynamic main menu and sub menu using php and mysql row = mysql_fetch_assoc($result)) { if ($row['Count'] > 0) { echo “” . $row['label'] . “”; display_menu($row['id'], $level + 1); echo “”; } elseif ($row['Count']==0) { echo “” . $row['label'] . …
Post: Replication in MySQL 5.6: GTIDs benefits and limitations - Part 2
May 30, 2013 By 6 Comments
…and therefore s3 and s4 are also lagging behind). s2> select count(*) from t; +———-+ | count(*) | +———-+ | 2 | +———-+ # s1 is behind s1> select count(*) from t; +———-+ | count…and use mysqlbinlog with the good old –start-position option! Even with GTIDs, you cannot totally…
Post: Choosing a MySQL HA Solution - Post-Webinar Q&A
June 7, 2013 By Leave a Comment
…if you’re trying to limit the amount of data …and its binary logs are fully intact, and then the binary log filters are executed on the intermediate server, thus resulting…give it a shot. I set up a 3 node cluster in AWS, got the volume mounted, and… –skip-grant-tables and insert a few rows into an …
Post: Implementing SchemaSpy in your MySQL environment
June 4, 2013 By 2 Comments
… HTML links and entity-relationship diagrams. It’s also designed to help resolve the obtuse errors that a database sometimes gives related… sometimes you need to give it a little help in the form of metadata files. Installation of SchemaSpy and Dependencies Download the… children, parents, count of columns, row counts, and comments — a great way for a high level overview of the table sizes and an easy way…
Post: MySQL and the SSB - Part 2 - MyISAM vs InnoDB low concurrency
May 22, 2013 By Leave a Comment
… seems that InnoDB performs better when a larger number of rows must be joined together (Q4.1, Q4.2) but worse… are limitations which MyISAM imposes that are difficult to work with. MyISAM does not maintain checksum consistency during regular operations and is not ACID compliant. MyISAM and InnoDB may perform differently under concurrency, which…
Post: Replication in MySQL 5.6: GTIDs benefits and limitations - Part 1
May 21, 2013 By 8 Comments
… specific replication topology. However you should keep in mind some limitations of the current implementation. This post is the first one… one by one. Second try: GTIDs enabled, mixing regular replication and GTID replication This time, we will enable GTID replication on…
Post: Percona Server 5.1.69-14.7 now available: A drop in replacement for MySQL
June 10, 2013 By 3 Comments
…_STATISTICS, TABLE_STATISTICS, THREAD_STATISTICS, and USER_STATISTICS) led to the maximum counter values being limited to 32-bit signed integers. Fixed…_CHANGED_PAGES query started returning data to indicate an incomplete result set. Bug fixed #1185040. Fixed the upstream bug #69379 which…
Comment: ZFS on Linux and MySQL
June 8, 2013 By 17 Comments
… not easy going from Linux to illumos ZFS by giving up 10% total ram for metadata caching, but it is just the… is the only stable illumos distro designed for server usage, and it can be bought with an optional tech support agreement. OpenIndiana is desktop oriented, and not quite stable, IMHO, and its lead developer just quit, so I consider…
Post: Multicast replication in Percona XtraDB Cluster (PXC) and Galera
June 5, 2013 By
…, maybe not as much as you think. While the theoretical limit of 1Gbps is actually 120MBps, I start to get nervous… blocking the master from taking writes if bandwidth is constrained and the slaves lag for a bit, not so in Galera…, we need to shut it down, configure our mcast address and re-bootstrap it: [root@node3 mysql]# service mysql stop [root…
