Emergency

Search Results for: duplicate key update

Why “insert … on duplicate key update” May Be Slow, by Incurring Disk Seeks

In my post on June 18th, I explained why the semantics of normal ad-hoc insertions with a primary key are expensive because they require disk seeks on large data sets. I previously explained why it …

Read More
 

INSERT ON DUPLICATE KEY UPDATE and REPLACE INTO

Jonathan Haddad writes about REPLACE INTO and INSERT ON DUPLICATE KEY UPDATE. Really, Why MySQL has both of these, especially both are non ANSI SQL extensions ? The story here seems to be the following …

Read More
 

INSERT ON DUPLICATE KEY UPDATE and summary counters.

INSERT … ON DUPLICATE KEY UPDATE is very powerful but often forgotten MySQL feature. It was introduced in MySQL 4.1 but I still constantly see people unaware of it. Myself I like this feature big …

Read More
 

TokuDB Fast Update Benchmark

Last month my colleague Rich Prohaska covered the technical details of our “Fast Update” feature which we added to TokuDB in version 6.6.  The message based architecture of Fractal Tree Indexes allows us to defer certain operations …

Read More
 

Fast Updates with TokuDB

With TokuDB v6.6 out now, I’m excited to present one of my favorite enhancements: fast updates with TokuDB. Update intensive applications can have their throughput limited by the random read capacity of the storage system. …

Read More
 

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 …

Read More
 

Updates & Discipline

So far, I’ve analyzed point and range queries. Now it’s time to talk about insertions and deletions. We’ll call the combination updates. Updates come in two flavors, and today we’ll cover both. Depending on the …

Read More
 

Duplicate indexes and redundant indexes

About every second application I look at has some tables which have redundant or duplicate indexes so its the time to speak about these a bit. So what is duplicate index ? This is when …

Read More
 

Percona Server 5.6.25-73.0 is now available

Percona is glad to announce the release of Percona Server 5.6.25-73.0 on July 1, 2015. Download the latest version from the Percona web site or from the Percona Software Repositories. Based on MySQL 5.6.25, including all the bug …

Read More
 

Percona XtraDB Cluster 5.6.24-25.11 is now available

Percona is glad to announce the new release of Percona XtraDB Cluster 5.6 on June 3rd 2015. Binaries are available from downloads area or from our software repositories. Based on Percona Server 5.6.24-72.2 including all …

Read More