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Search Results for: primary key in all indexes

10x Insertion Performance Increase for MongoDB with Fractal Tree Indexes

The challenge of handling massive data processing workloads has spawned many new innovations and techniques in the database world, from indexing innovations like our Fractal Tree® technology to a myriad of “NoSQL” solutions (here is …

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Find unused indexes

I wrote one week ago about how to find duplicate indexes. This time we’ll learn how to find unused indexes to continue improving our schema and the overall performance. There are different possibilites and we’ll …

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Find and remove duplicate indexes

Having duplicate keys in our schemas can hurt the performance of our database: They make the optimizer phase slower because MySQL needs to examine more query plans. The storage engine needs to maintain, calculate and …

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Hijacking Innodb Foreign Keys

I guess I’m first to post in 2012 so Happy New Year all blog readers ! Now back to HardCore MySQL business – foreign Keys. MySQL supported Foreign Keys for Innodb for many years, yet …

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On “Replace Into”, “Insert Ignore”, and Secondary Keys

In posts on June 30 and July 6, I explained how implementing the commands “replace into” and “insert ignore” with TokuDB’s fractal trees data structures can be two orders of magnitude faster than implementing them …

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EXPLAIN EXTENDED can tell you all kinds of interesting things

While many people are familiar with the MySQL EXPLAIN command, fewer people are familiar with “extended explain” which was added in MySQL 4.1 EXPLAIN EXTENDED can show you what the MySQL optimizer does to your …

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How (not) to find unused indexes

I’ve seen a few people link to an INFORMATION_SCHEMA query to be able to find any indexes that have low cardinality, in an effort to find out what indexes should be removed.  This method is …

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Multi Column indexes vs Index Merge

The mistake I commonly see among MySQL users is how indexes are created. Quite commonly people just index individual columns as they are referenced in where clause thinking this is the optimal indexing strategy. For …

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Statistics of InnoDB tables and indexes available in xtrabackup

If you ever wondered how big is that or another index in InnoDB … you had to calculate it yourself by multiplying size of row (which I should add is harder in the case of …

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MySQL 5.1 Grammar Changes to Support Clustering Indexes

This post is for storage engine developers that may be interested in implementing multiple clustering keys. After blogging about TokuDB’s multiple clustering indexes feature, Baron Schwartz suggested we contribute the patch to allow other storage …

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