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varokism: décembre 2011

http://varokism.blogspot.com/2011_12_01_archive.html

Mercredi 21 décembre 2011. Fine tuning read rnd buffer size and read buffer size. Those variables are easy to tune. The evidence popup here between 128 and 256K for in memory workload. In myisam.cc my default record cache size is set to global system variables.read buff size;. To show IO size :. Strace -p id mysqld -e read -e write. In InnoDB the difference come with prefetch trigger when no fragmentation. It is the case when rows are inserted in increasing primary key order. So conservative read...As we...

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varokism: Howto - Move a table to different schema with no outage

http://varokism.blogspot.com/2015/04/howto-move-table-to-different-schema.html

Jeudi 16 avril 2015. Howto - Move a table to different schema with no outage. I remember a time when it was debate if views can be useful for a web oriented workload? This post is about one good use case:. The story is that some tables have been creating into a schema and used by the application into same connection. Later on some more schema have been added to separate data for multiple application domain but still using original table, kind of cross domain universal table. CREATE DATABASE schema1;.

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varokism: MariaDB Storage Engine for CCM forum

http://varokism.blogspot.com/2013/07/mariadb-storage-engine-for-ccm-forum.html

Vendredi 5 juillet 2013. MariaDB Storage Engine for CCM forum. CCM Benchmark is one of the leading forum provider on the web, ROI is a major concern for them and historically MyISAM was used on the forum replication cluster. Reason is that MyISAM gave better ROI/performance on data that is hardly electable to cache mechanism. Like many other big web players at an other scale, Damien need to scale on disk not because it's good, but because you can catch more with less hardware. Doing this you need to ...

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varokism: janvier 2011

http://varokism.blogspot.com/2011_01_01_archive.html

Lundi 17 janvier 2011. Muzing on NoSQL, damned! Can't get rid of InifiniDB. NoSQL have been frequently used for building analytic solutions. The big picture is using some scalable client code with m. Ap reduce to distribute full data scan. This approach have nothing new to the RDBMS world and can be considered an extension of the. Kimball ROLAP normalization, just allowing more CPU power on a single query. NoSQL or sharding take advantages on. Per column data type. Optimization and deserialization cost.

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varokism: MariaDB world record price per row 0.0000005$ on a single DELL R710

http://varokism.blogspot.com/2013/12/mariadb-world-record-price-per-row.html

Mercredi 11 décembre 2013. MariaDB world record price per row 0.0000005$ on a single DELL R710. Don't look at an industry benchmark here, it's a real client story. 200 Billion records in a month and it should be transactional but not durable. For regular workload we use LOAD DATA INFILE into partitioned InnoDB, but here we have estimated 15TB of RAID storage. This is a lot of disks and it can't no more stay inside a single server internal storage. First let's check the compression with the dataset. Affic...

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varokism: novembre 2011

http://varokism.blogspot.com/2011_11_01_archive.html

Vendredi 18 novembre 2011. Alter table engine TokuDB. At the le MUG. Some questions raised on TokuDB, i hope this post will answer more in deph details. InnoDB like any other general purpose RDBMS can be really bad for online back-office with big tables, despite following some usual practice and OLTP normalize schema. Having indexes in memory. Touching a minimum set of rows for secondary index scan. Scanning some range in primary key order. This happen frequently when. Iostat –xm 2. Every primary key are...

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varokism: février 2013

http://varokism.blogspot.com/2013_02_01_archive.html

Vendredi 15 février 2013. Dropping MySQL partitions for MariaDB Dynamic column. In the same time of passionate debat of the best distribution MySQL vs MariaDB on a 120K Euro server( here. I wanted to share the story of drop of InnoDB insert performance for one of our client having a tables between 10 to 100 Billions rows. In most case this size of table is just a no go in relationnel database. So why it used to work so far? C1 int, c2 tinyint, c3 mediumint, c4 binary(1), c5 float . C2 avg cardinality 1000.

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varokism: Social Networking Using OQGraph

http://varokism.blogspot.com/2015/04/social-networking-using-oqgraph.html

Vendredi 17 avril 2015. Social Networking Using OQGraph. I was given the chance to experiment typical social networking query on an existing 60 Millions edges dataset. And 16 more connections in common. Such algorithms and others are simply hardcoded into the OQGraph. With the upgrade of OQGraph V3 into MariaDB 10 we can proceed directly on top of the exiting tables holding the edges kine of featured VIRTUAL VIEW. CREATE OR REPLACE TABLE `relations` (. Id1` int(10) unsigned NOT NULL,. KEY `id1` (`id1`),.