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MVCC applies to isolation levels read-committed and repeatable read (default). You don't need to specify anything for both of these features to work together. Maybe one way to think about it, is t …

So I'm answering this question almost 4 years late: InnoDB file formats were conceived at a time when InnoDB was independent of the MySQL Server (for example: MySQL 5.1 could run two different versions … of InnoDB). …

As others have answered your first question, I will answer the second: Do we need to make any changes in the my.ini file if any variable(s) are configured wrongly and also to improve the performan …

There are a few things I can clarify for you here: Yes, it is a good practice to delay secondary index creation until after you import the data (starting from MySQL 5.5 - not before). Mysqlpump doe …

Useful diagnostics to be able to see these locks: SHOW CREATE TABLE pics SHOW ENGINE INNODB STATUS SELECT * FROM information_schema.innodb_trx Index structure affects locking (hence SHOW CREATE TABLE … SHOW ENGINE INNODB STATUS and innodb_trx will show information about which row locks are conflicting, and which statements. …

InnoDB will not be able to overwrite log file space if it contains changes that have not been modified on disk yet. … So historically, what would happen is that InnoDB would attempt a certain amount of work per second (configured by innodb_io_capacity) and if that was not enough, you would reach full log space. …

I can see from inside InnoDB status, that it doesn't appear to be InnoDB consuming the memory (assuming you collected this from when the problem was occurring): Total memory allocated 26217103360; in … additional pool allocated 0 Dictionary memory allocated 1212141 Buffer pool size 1563519 Total memory: 24.41 GiB (InnoDB needs about 5-10% more than your buffer pool for internal structures) Buffer …

Here are my suspicions: mysqld is restarting for some reason, leaving the buffer pool cold on restart. This can be eliminated by SHOW GLOBAL STATUS (uptime column) and looking at the error log for …

Starting with MySQL 5.5 InnoDB uses a modified LRU algorithm to prevent table-scans from filling the buffer pool. By default only 3/8ths of the buffer pool is available to table-scans. …

I would recommend using InnoDB memcached over Handlersocket. … The advantage of InnoDB memcached is that: It uses a standard memcached protocol, with drivers available for many programming languages. …

If you are concerned with the size, maybe try using InnoDB page compression, or compress the blobs in your application before storing them? You'll probably find the TEXT column compresses very well. …

You can use statement-based replication and add the column to a slave first. Any pending modifications will queue up on the slave, and apply once the alter has complete. When the slave is fully up t …

InnoDB reserves additional memory for buffers and control structures, so that the total allocated space is approximately 10% greater than the specified size. …

You can kind of do this from MySQL 5.6 and onwards using information_schema. I have an example of finding the ideal buffer pool size on my blog here: http://www.tocker.ca/2013/05/31/estimating-mysqls …

The ~/.my.cnf file is usually used for client options (for example changing the default port or host). mysqld will likely start as a different user and will not read your .my.cnf file. It is recomme …