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Generated (Virtual) Columns in MySQL 5.7 (labs)

About 2 weeks ago Oracle published the MySQL 5.7.7-labs-json version which includes a very interesting feature called “Generated columns” (also know as Virtual or Computed columns). MariaDB has a similar feature as well: Virtual (Computed) Columns.

The idea is very simple: if we store a column

`FlightDate` date

in our table we may want to filter or group by year(FlightDate), month(FlightDate) or even dayofweek(FlightDate). The “brute-force” approach: use the above Date and Time MySQL functions in the query; however it will prevent MySQL from using an index (see below). Generated columns will allow you to declare a “Virtual”, non-stored column …

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Feedback directed optimization with GCC and Perf


Gcc 5.0 has added support for FDO which uses perf to generate profile. There is documentation for this in gcc manual, to quote:

-fauto-profile=path
Enable sampling-based feedback-directed optimizations, and the following optimizations which are generally profitable only with profile feedback available: -fbranch-probabilities, -fvpt, -funroll-loops, -fpeel-loops, -ftracer, -ftree-vectorize,
-finline-functions, -fipa-cp, -fipa-cp-clone, -fpredictive-commoning, -funswitch-loops, -fgcse-after-reload, and -ftree-loop-distribute-patterns.
path is the name of a file containing AutoFDO profile information. If omitted, it defaults to fbdata.afdo in the current directory.
Producing an AutoFDO …

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Netbeans 8 – Fedora

Some of my students want to use the Fedora image that I built for my database classes in my Java software development life cycle course. As a result, they wanted a Java development environment installed. I examined JDeveloper 11g (11.1.1.7.0) and 12c (12.1.3) but resolved on the more generic Netbeans 8 (8.0.2) IDE.

JDK 7 with Netbeans 8 Download

You can download the generic Netbeans 8 IDE, the JDK 7 with Netbeans, or the JDK 8 with Netbeans for the Linux installation. After you download the executable program, you should follow these instructions to install the Netbeans 8 IDE on Fedora.

As the …

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Daily Reports Send Top Queries to Your Inbox

We know you are busy, and checking the VividCortex interface is not always on the top of your priority list. That’s why we implemented our proactive reporting feature.

Each day, your team will receive a recap of the top ten queries of each environment from the day prior. You can see at a glance whether systems were running smoothly or if you need to look into performance.

If daily reports are creating too much noise, you can subscribe to weekly reports instead. These will show the top ten queries of each environment from the week prior.

Of course, if you do not wish to receive the reports, simply unsubscribe.

This is the first of many proactive features to bring database monitoring to everyone on your team. Stay tuned for more, and sign up for a free trial if you are interested in a monitoring solution that …

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Catena: A High-Performance Time-Series Storage Engine

There are plenty of storage engines out there, but none of them seem to offer fast and efficient time series storage and indexing. The existing options like RRDtool and Whisper aren’t very fast, and the fast options like LevelDB aren’t specifically made for time series and can lead to harsh operational issues. Instead of hacking on something like LevelDB to suit his needs, Preetam Jinka, one of the team’s brainiacs, decided to write his own storage engine.

Join us Tuesday, June 2nd at 2 PM EST (6 PM GMT), as Preetam Jinka covers the unique characteristics of time series data, time series indexing, and the basics of log-structured merge (LSM) trees and B-trees. After establishing some basic concepts, he will explain how Catena’s design is inspired by many of the existing systems today and why it works much better than its present alternatives.

Designing a storage engine is the easy part. Implementation is …

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MySQL 5.7 — Native Systemd Support

Introduction

Systemd is a management and configuration platform available in all major Linux distributions. It provides infrastructure for service start, stop, restart and several other novel functionalities to manage services. Systemd replaces SysV and upstart initialization systems and is the default init system in most modern Linux distributions including Red Hat Enterprise Linux, Oracle Linux, Debian, Ubuntu, Fedora, SLES and openSUSE.

Preliminary support for systemd was introduced in earlier versions of MySQL. However, it had the following limitations and disadvantages:

  1. Use of ping tricks to check whether mysqld is ready to serve client connections.
  2. Though systemd had superior process control for automatic restarts, mysqld_safe was still used to identify abnormal mysqld termination and do automatic restarts.
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The Perfect Server - Debian 8 Jessie (Apache2, BIND, Dovecot, ISPConfig 3)

This tutorial shows how to prepare a Debian Jessie server (with Apache2, BIND, Dovecot) for the installation of ISPConfig 3 and how to install ISPConfig 3. The webhosting control panel ISPConfig 3 allows you to configure the following services through a web browser: Apache web server, Postfix mail server, Dovecot IMAP/POP3 server, MySQL, BIND nameserver, PureFTPd, SpamAssassin, ClamAV, and many more.

How-to extract from mysqldump | mysql-dump-splitter recipes

This post will answer how to extract database, tables etc from mysqldumpsplitter utility.

The post How-to extract from mysqldump | mysql-dump-splitter recipes first appeared on Change Is Inevitable.

Test your knowledge: Percona XtraDB Cluster (PXC) quiz

I often talk with people who are very interested in the features of Percona XtraDB Cluster (PXC) such as synchronous and parallel replication, multi-node writing and high availability. However some get confused when operating a real PXC cluster because they do not fully realize the implications of these features. So here is a fun way to test your PXC knowledge: try to solve these 12 questions related to PXC! (you will find the answers at the end of the post.)

Workload

1. With Galera 3.x, support for MyISAM is experimental. When can we expect to have full MyISAM support?
a. This will never happen as Galera is designed for transactional storage engines.
b. This is planned for Galera 4.0.

2. Why aren’t all workloads a good fit for PXC?
a. Execution plans can change compared to a regular MySQL server, so performance is sometimes not as good as with a regular MySQL server.
b. Large …

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Monitoring To Success

The mantra of the day is – performance, performance, performance! It is clear that everything needs to be totally available all of the time, function at the fastest speeds and performance as close to perfect as is possible. In all the business discussions swirling around us we hear the words; application performance, website performance, transaction performance, server performance and on and on in regards to virtually everything digital that we live and breath with. Performance is no longer just one of the items we need to be paying attention to, it is THE item we need to be critically aware of every minute of every day! No longer are the words “it’s good enough” acceptable. The impacts to business can be catastrophic if the digital performance of your business is not at the highest levels. So the question we are all challenged with is how can we be sure that the performance levels we need are actually what we are …

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