If a table-full error occurs, it may be that the disk is full or that the table has reached its maximum size. The effective maximum table size for MySQL databases is usually determined by operating system constraints on file sizes, not by MySQL internal limits.

Limits on Table size : The following table lists some examples of operating system file-size limits. This is only a rough guide and is not intended to be definitive.

If you do encounter a full-table error, there are several reasons why it might have occurred:

• The disk might be full.
• The InnoDB storage engine maintains InnoDB tables within a tablespace that can be created from several files. This enables a table to exceed the maximum individual file size , check InnoDB tablespace (ibdata1)
• You are using MyISAM tables on an operating …

One day on production server I encountered this error message, So I found out a solution for it as:

There are multiple reasons, listed below:

1. You’ve run out of memory available to MySQL.This is the most likely problem you’re facing. Each connection in MySQL’s connection pool requires memory to function, and if this resource is exhausted, no further connections can be made. Of course, the memory footprints and maximum packet sizes of various operations can be tuned in your equivalent to my.cnf if you discover this to be an issue.

You can calculate MySQL memory using this tool – http://www.mysqlcalculator.com/

This shows maximum size a MySQL should use in your environment, in my case it’s a dedicated MYSQL …

When a new version of MySQL appears, the first source of information for the brave experimenter is a page in the manual named What is new in MySQL X.X, also known as MySQL in a nutshell. For MySQL 5.7, the in-a-nutshell page lists quite a lot of changes. In that page, the list of removed features is enough to send a chill down the spine of most any DBA. Some of the items in the deprecation section are removals in disguise, as they require immediate, rather than delayed, action to use the new version with existing application (SET …

This is getting more and more common, so I wanted to provide the steps required to get LDAP authentication working with MariaDB PAM plugin.

Unless you’re already familiar with setting up the MariaDB PAM plugin, I’d first recommend getting this to work with a standard Linux user (steps 1-4), then once all is working fine, progress to the LDAP users (steps 5-10). (And if you do not want to test this for the Linux user account, then you may skip steps #2 and #3.)

1. Enable plugin by running the following from the command line client:

   INSTALL SONAME 'auth_pam';

   You should see an entry like this afterward in SHOW PLUGINS:

       | pam | ACTIVE | AUTHENTICATION | auth_pam.so | GPL |

2. Create the mysql user account (note it does not have a password, as it will obtain this from your Linux user, and eventually the LDAP account) and provide it with the GRANTS you want it to …

I’ve had a look at a preview release of MySQL 5.7.8, some time before it became available to the general public (perks and duties of an Oracle ACE) and I found a few interesting things among the release notes and the tarball itself:

• There is a new tool named mysqlpump, which is intended as a replacement for mysqldump, with parallel processing, compression, progress watch, the long awaited ability of excluding databases or tables, and more.
• The json functionality has been fished out from the labs and added to the main distribution.

The MySQL Development team is very happy to announce that MySQL 5.7.8, the second 5.7 Release Candidate (RC2), is now available for download at dev.mysql.com (use the “Development Releases” tab).

We have fixed over 500 bugs in 5.7.8. This is on top of what we delivered in 5.7.7 and on top of bug fixes up-merged from 5.6.…

Percona is glad to announce the release of Percona XtraBackup 2.2.12 on August 3, 2015. Downloads are available from our download site or Percona Software Repositories.

Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. Offered free as an open source solution, Percona XtraBackup drives down backup costs while providing unique features for MySQL backups.

Bugs Fixed:

• Percona XtraBackup would segfault during the prepare …

In my recent benchmarks for MongoDB, we can see that the two engines WiredTiger and TokuMX struggle from periodical drops in throughput, which is clearly related to a checkpoint interval – and therefore I correspond it to a checkpoint activity.

The funny thing is that I thought we solved checkpointing issues in InnoDB once and for good. There are bunch of posts on this issue in InnoDB, dated some 4 years ago.  We did a lot of research back then working on a fix for Percona Server

• https://www.percona.com/blog/2011/04/04/innodb-flushing-theory-and-solutions/
• …

http://dom.as/2015/07/30/on-order-by-optimization/

An insightful exploration by Domas (Facebook) on how some of the MySQL optimiser’s decision logic is sometimes naive, in this case regarding ORDER BY optimisation.

Quite often, “simple” logic can work better than complex logic as chasing all the corner cases can just make things worse – but sometimes, logic can be too simple.

Everything must be made as simple as possible, but no simpler.
— Albert Einstein / Roger Sessions

This Log Buffer Edition throws spotlight on some of the salient blog posts from Oracle, SQL Server and MySQL.

Oracle:

• STANDARD date considerations in Oracle SQL and PL/SQL
• My good friend, Oracle icon Karen Morton passed away.
• Multiple invisible indexes on the same column in #Oracle 12c
• Little things worth knowing: Data Guard Broker Setup changes in 12c …