As the festive season of holidays draws near, there is a spring in the blogosphere. This Log Buffer edition anticipates that and picks some lively blog posts from Oracle, SQL Server and MySQL.

Oracle:

• Truncate is one of those commands that cannot be undone trivially…In fact, you might well be looking at a database recovery in order to get a truncated table back to a “full” state.
• It should be rare to see many TNS listener processes running on 1 OS. Some listeners are even Global Data Services listener.
• The fact that an extension explicitly created by a user through …

Fri, 2015-12-18 09:01geoff_montee_g

Several months ago, I wrote a blog post about configuring PAM authentication and user mapping in MariaDB. While it is useful to map a system user account to a MariaDB user account, a lot of users actually wanted to be able to map all system users in a particular system group to the same MariaDB user account without mapping the system accounts individually. This was not supported by the PAM user mapping plugin when I wrote the original blog post, but this feature was recently added.

The new group mapping feature of the PAM user mapping plugin allows users to do things like map every system user in the dba system group to the dba MariaDB user account, while still requiring the system …

In the previous post for this ongoing “EXPLAIN FORMAT=JSON is Cool!” series, we discussed covered indexes and how the 

used_columns

  array can help to choose them wisely. There is one more type of multiple-column indexes: composite indexes. Composite indexes are just indexes on multiple columns. Covered indexes are a subgroup of the larger set “composite indexes.” In this post we’ll discuss how “used_key_parts” can help show …

Severalnines ClusterControl Helps Organizations
Deploy, Monitor, Manage and Scale Percona Server for MongoDB

Severalnines, the provider of open source database management tools, and Percona, the company that delivers enterprise-class MySQL® and MongoDB® solutions and services, this week announced they are expanding their partnership to offer ClusterControl for Percona Server for MongoDB, enabling subscribers of Percona Support for MongoDB to access the advanced deployment, monitoring, management, and scaling solutions available from Severalnines. The combination of Percona Server for MongoDB and Severalnines ClusterControl enables organizations to cost-effectively deploy, monitor, manage and scale a NoSQL database infrastructure.

Percona has offered Severalnines ClusterControl for …

In November we held our first MySQL 5.8 planning session in London. On behalf of the MySQL team, I would like to thank you for your feature requests and suggestions. We reviewed over 150 pieces of feedback in total, and are looking forward to prioritizing a number of suggestions:

In MySQL 5.8, we are planning to make two important changes to modernize our code base.…

Percona is glad to announce the release of Percona XtraBackup 2.3.3 on December 17th, 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.

…

Knowing which privileges a given account has is easy – just issue SHOW GRANTS FOR user@host.  But what about when you need visibility into privileges from the other direction – which accounts can access specific data?  If you’re a DBA – or perform DBA duties, regardless of your title – you may have been asked this question.  It’s an important question to ask in an audit or compliance review – but it can be a difficult question to answer.    This post will walk through how to assess this, but if you’re impatient and need answers to this question immediately, jump to the end – there’s a simple shortcut.

Things to consider

There are a few things you’ll want to consider about the implementation of the MySQL privilege system as you try to sort out who has access to certain data.

Access type

MySQL can restrict privileges based on operations – somebody who has …

We work on data recoveries quite often. In many cases, we recover table structures from the .frm files because there was no backup available. There is already a great blog post by my colleague Miguel Ángel Nieto about how we can recover structures from .frm files using MySQL utilities.

This works pretty well and we prefer to run mysqlfrm with the “–server” option to get all possible information from a .frm file. However, this option expects that MySQL is up and running so that mysqlfrm can spawn a new MySQL instance, and run the structure recovery there.

Recently I came across a tool that makes this job easier. The name of tool is …

The guys at Yahoo released their partition management script on github:

At Yahoo, we manage a massive number of MySQL databases spread across multiple data centers. We have thousands of databases and each database has many partitioned tables. In order to efficiently create and maintain partitions we developed a partition manager which automatically manages these for you with minimal pre

Hello! I have posted this entry on the MySQL Server team's blog:

Using the aggregate functions ANY, SOME, EVERY with MySQL  .