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Search Results for: row length

Looking deeper into InnoDB’s problem with many row versions

A few days ago I wrote about MySQL performance implications of InnoDB isolation modes and I touched briefly upon the bizarre performance regression I found with InnoDB handling a large amount of versions for a single …


Big trouble with zero-length character columns in TokuDB

What good is a zero-length character column in a MySQL table? A zero-length character column has type of ‘char(0)’. If it is nullable, then it can at least store one bit. If it is not …


Why is the ibdata1 file continuously growing in MySQL?

We receive this question about the ibdata1 file in MySQL very often in Percona Support. The panic starts when the monitoring server sends an alert about the storage of the MySQL server – saying that …


Dynamic row format for MEMORY tables

The latest Percona Server release has one new feature: now MEMORY tables can have BLOB and TEXT columns, and VARCHAR columns will not waste space due to implicit extension to CHAR.


Innodb row size limitation

I recently worked on a customer case where at seemingly random times, inserts would fail with Innodb error 139. This is a rather simple problem, but due to it’s nature, it may only affect you …


Getting MySQL to use full key length

There is one bug, or “missing feature” in MySQL Optimizer which may give you hard time causing performance problems which may be hard to track down, it is using only part of the index when …


Indexing Big Data – NSF Workshop on Research Directions in the Principles of Parallel Computation

I attended the NSF Workshop on Research Directions in the Principles of Parallel Computation in Pittsburgh on 6/27/12. The workshop brought together researchers from academia and industry to explore visions for the future of parallel computing. …


Loading Tables with TokuDB 4.0

Often, the first step in evaluating and deploying a database is to load an existing dataset into the database. In the latest version, TokuDB makes use of multi-core parallelism to speed up loading (and new …


How number of columns affects performance ?

It is pretty understood the tables which have long rows tend to be slower than tables with short rows. I was interested to check if the row length is the only thing what matters or …


Efficient Boolean value storage for Innodb Tables

Sometimes you have the task of storing multiple of boolean values (yes/now or something similar) in the table and if you get many columns and many rows you may want to store them as efficient …