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Previous 30 Newer Entries Showing entries 121 to 150 of 840 Next 30 Older Entries

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The Data Day, Two days: January 25/28 2013
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Informatica’s revenue is in. Hortonworks joins OpenStack. And more.

For 451 clients: Jitterbit gives integration stack makeover, continues to mine salesforce.com bit.ly/VJrwPE By Krishna Roy

— Matt Aslett (@maslett) January 28, 2013

For 451 clients: Enterprise cloud provider Skytap offers new service based on Cloudera Hadoop bit.ly/UpnXij By @rachelchalmers

— Matt Aslett (@maslett) January 25, 2013

For 451 clients: Alteryx plots course for 2013 as it seeks to bring business users into

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MySQL Replication with Global Transaction Identifiers – Step-by-Step Install and Addition of Slaves – Part Two
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This post is part two of MySQL Replication with Global Transaction Identifiers – Step-by-Step Install and Addition of Slaves. In this post, I will be showing you how to use the MySQL Utility Script mysqlreplicate to create a new replication slave off a master database.

This is also the fourth in a series that I will be doing on MySQL

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Fatal Half-measures in Incident Response
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CSO Online writes about a rather sad list of security breaches at http://www.csoonline.com/article/721151/fatal-half-measures-in-incident-response, and the half-hearted approach companies take in dealing with the security on their networks and websites.

What I find most embarrassing is that it appears (judging by the actions) that many companies have their lawyers do some kind of borked risk assessment , and decide that they can just leave things as-is and yell foul when there’s a breach. After all, particularly in the US prosecutors are very heavy handed with breaches, even when the company has been totally negligent. That’s weird, because an insurance company wouldn’t pay out for a break-in when you’ve left your front door wide open! The problem is of

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The Data Day, A few days: January 17-22 2013
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DataStax and VoltDB launch their version 3.0s. And more

For 451 Research clients: DataStax adds security and manageability to distributed NoSQL database bit.ly/Vb1IiT

— Matt Aslett (@maslett) January 18, 2013

For 451 clients: LogiXML serves up fresh cut of BI stack with an eye to more embedded analytics deals bit.ly/SppzsH By Krishna Roy

— Matt Aslett (@maslett) January 21, 2013

Inside H-P’s Missed Chance To Avoid a Disastrous Deal – WSJ.com on.wsj.com/Td7wrh via @

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MySQL Replication with Global Transaction Identifiers – Step-by-Step Install and Addition of Slaves – Part One
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One of my favorite features of MySQL (http://mysql.com) is replication. Replication provides you with the ability to have MySQL automatically copy data from one MySQL instance to another. There are many benefits to using replication, but I just like having an extra copy of my data on another server in case the main server crashes. But if the master crashes, I can then use the MySQL mysqlfailover script to automatically failover from the master to the slave. (see my earlier post – Using the MySQL Script mysqlfailover for Automatic Failover

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The Data Day, Two days: January 15/16 2013
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Funding for Ayasdi and Zettaset. NuoDB launches cloud database. And more

For 451 Research clients: NuoDB launches distributed ‘cloud data management system’ bit.ly/UO3ssM

— Matt Aslett (@maslett) January 15, 2013

For 451 clients: Armed with $20m series C, Lattice Engines looks to bring sales intelligence inside bit.ly/11z4VdF By Krishna Roy

— Matt Aslett (@maslett) January 16, 2013

Ayasdi Launches with $10 Million from Khosla Ventures and FLOODGATE. bit.ly/X7oemJ

— Matt Aslett (@maslett)

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Retrieving List of MySQL Users and Grants with Perl
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Before I upgrade MySQL to the latest and greatest version, one of the first things that I do is export the user and grant information. In the past, I would keep all of my user information (user name, password, grants) in a text file, with the SQL for each user/grant ready to be executed on the upgraded server. I did use my own form of “mental encryption” for my passwords, so the passwords weren’t in plain English. But then I would have to decode my passwords each time before I executed the SQL statements.

When I upgrade, I usually like to dump all of the data and import it into the new version, so I have a fresh copy of the database. The MySQL server that I have is for my personal use and the data size is relatively small, so for my case it doesn’t take long to import the data.

But there were times when I

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MySQL Replication – Multi-Threaded Slaves (Parallel Event Execution)
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If you aren’t familiar with MySQL replication, “Replication enables data from one MySQL database server (the master) to be replicated to one or more MySQL database servers (the slaves). Replication is asynchronous by default – slaves need not to connected permanently to receive updates from the master. This means that updates can occur over long-distance connections and even over temporary or intermittent connections such as a dial-up service. Depending on the configuration, you can replicate all databases, selected databases, or even selected tables within a database.” (From: http://dev.mysql.com/doc/refman/5.5/en/replication.html).

I use MySQL replication on my home office server. I don’t really have much data to store, but it

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MySQL@FOSDEM 2013: Call for papers closes in a few days!
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This is just a reminder: Call for papers for MySQL & Friends devroom at FOSDEM 2013 is open until December 21st, which is this Friday. Please hurry up and submit your proposal. Possible topics include everything related to MySQL.

New optimization in MariaDB 10.0: EXISTS-to-IN subquery rewrite
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MariaDB 10.0 has got another new feature: Sanja Byelkin has pushed EXISTS-to-IN rewrite feature. It is an optimization targeted at EXISTS subqueries. The idea behind it is simple. EXISTS subqueries often have form:

EXISTS (SELECT …  FROM … WHERE outer_col=inner_col AND inner_where)

where outer_col=inner_col is the only place where the subquery has references to outside. In this case, the subquery can be converted into an uncorrelated IN:

outer_col IN (SELECT inner_col FROM … WHERE inner_where)

The conversion opens new opportunities for the optimizer. Correlated EXISTS subquery has only one execution strategy. Uncorrelated IN subquery has two:

  • re-run the subquery every time the subquery is evaluated (the same as in EXISTS)
  • Materialize the
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    Using the MySQL Script mysqlfailover for Automatic Failover with MySQL 5.6 GTID Replication
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    This post is the second in a series that I will be doing on MySQL Workbench Utilities – Administer MySQL with Python Scripts. You may want to read the first half of this post to understand how MySQL Workbench Utilities work and how you access the scripts. These scripts were written by Chuck Bell (a MySQL (http://mysql.com) employee)

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    On Big Data, Analytics and Hadoop. Interview with Daniel Abadi.
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    “Some people even think that “Hadoop” and “Big Data” are synonymous (though this is an over-characterization). Unfortunately, Hadoop was designed based on a paper by Google in 2004 which was focused on use cases involving unstructured data (e.g. extracting words and phrases from Webpages in order to create Google’s Web index). Since it was not [...]
    MariaDB Foundation
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    You may have already seen the announcement MariaDB Foundation to Safeguard Leading Open Source Database. We at Open Query wholeheartedly support this (r)evolution of the MySQL ecosystem, which appears to be increasingly necessary as Oracle Corp is seriously dropping the ball with security updates and actually just general development and innovation. Oracle has actually done some very good work, I happily acknowledge that – but security issues are critical, having crashing bugs and incorrect query results in a .28 of a GA release is uncool, and not incorporating awesome development efforts by the community is just astonishing.

    MariaDB is where the

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    MariaDB security updates
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    Important Security Fix for a Buffer Overflow Bug: MariaDB 5.5.28a, 5.3.11, 5.2.13 and 5.1.66 include a fix for CVE-2012-5579, a vulnerability that allowed an authenticated user to crash MariaDB server or to execute arbitrary code with the privileges of the mysqld process. This is a serious security issue. We recommend upgrading from older versions as soon as possible.

    MariaDB 5.5.28a, 5.3.11, 5.2.13 and 5.1.66 (GA) binaries, packages, and source tarballs are now available for download from http://downloads.mariadb.org. So you can upgrade within your own major series.

    Note that while this fix has just been published, some other vulnerabilities have been noted over the weekend also. Below a summary of these other CVEs as documented by Red Hat Security Response Team, with annotations by Sergei Gulubchik who is the Security Coordinator for

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    MariaDB C client libraries and the end of dual-licensing
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    Finally there is an LGPL C client library for MariaDB, and thus also for MySQL. Monty Program and SkySQL have been working on this for some time. Admittedly there was already the BSD licensed Drizzle client library which was also able to talk to a MySQL/MariaDB server, however its API is different. The C client library for MariaDB has exactly the same API existing applications are used to, so you can just re-link and keep going! There is also a new LGPL Java client library for MariaDB.

    In case you don’t quite realise: this is actually a major thing.

    At MySQL AB, the client library was made GPL and this flowed through to Sun Microsystems and then Oracle Corp. This licensing

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    Simple MySQL: using TRIGGERs to keep datetime columns updated without direct SQL calls
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    If you’ve ever used non-opensource code, or applications that you don’t have complete control over, then you may have run into situations you need to alter data on a per-row basis but been unable to do so for lack of application SQL access. The solution to this type of problem is to use a MySQL TRIGGER, which allows us to execute arbitrary SQL commands when defined events occur. Why is this useful and how does it work? Well…

    For example, I have a freeRADIUS server that uses MySQL as a backend for the user authentication, and one of my server applications (HostBill) provides a freeRADIUS plugin that allows my users to manage their RADIUS accounts; however the default freeRADIUS schema lacks a DATETIME column on the user table. When a user is created (INSERT) or has their password changed (UPDATE)

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    2012 Holiday Gifts for MySQL DBAs
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    Last year a wrote a blog entry on holiday gifts for DBAs that went over quite well with the relatives and loved ones of DBAs. So if you are a MySQL DBA, print out a copy of this, circle the items you like, and get something you like this year. And yes, shopping for you is worse than styling Donald Trump’s hair in a high wind or explaining foreign keys to any cast member of any popular reality or music show. So take some pity on those who are buying you gifts.

    • Cafepress has a series of DBA shirts including ‘Not Normalized’ , ‘Kiss me — I’m the DBA’, and the Key Rule shirt.
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    Looking at MySQL 5.6’s optimizer: EXPLAIN UPDATE
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    MySQL 5.6 adds support for EXPLAIN UPDATE. This is a useful feature, so we want to have it in MariaDB 10.0, too. Besides that, MariaDB 10.0 has SHOW EXPLAIN feature, and we want it work for UPDATE commands, too.

    Now, a bit of code history. Why didn’t MySQL have EXPLAIN UPDATE from the start, like other database systems? To the uninformed, lack of EXPLAIN UPDATE looks like simple lazyness. After all, everyone who has read a database textbook can imagine that the code should have this form:

    run_update_query(UpdateQuery q) {
       QueryPlan qp= optimize_query(q);

    and adding EXPLAIN UPDATE is a matter of adding another function:

    run_explain_update(UpdateQuery q) {
       QueryPlan qp= optimize_query(q);
    print_update_query_plan(QueryPlan qp)
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    Set up and configure PostgreSQL ODBC drivers for the MySQL Workbench Migration Wizard
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    If you plan to use the MySQL Workbench Migration Wizard to migrate databases from PostgreSQL to MySQL you first need to configure an ODBC driver to connect to your PostgreSQL server.

    In this post I’ll cover how to set up and configure psqlODBC, the official ODBC driver for PostgreSQL.

    Installing the psqlODBC Driver

    The procedure is different for every platform so make sure to follow the instructions that correspond to the OS where you have MySQL Workbench installed. The driver needs to be installed in that machine, as explained in the MySQL Workbench documentation.


    If you are running MySQL Workbench on Windows download the MSI package for psqlODBC. Go

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    Extended keys: First in MariaDB 5.5, now in mysql-trunk, too
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    One of the optimizations we have introduced in MariaDB 5.5 is Extended keys. The idea behind it is rather simple. Inside InnoDB, every secondary index has an invisible suffix of primary key columns. That is, when you create an index:

    ALTER TABLE innodb_tbl ADD INDEX (column1, column2);

    you’re actually creating this

    ALTER TABLE innodb_tbl ADD INDEX (column1, column2, primary_key_column1, …, primary_key_columnN);

    The index is extended with primary key columns. SHOW KEYS does not show these extra key parts, but they are there.

    Traditionally, MySQL optimizer was half-aware of these extra columns. It knew that doing an index-only scan on InnoDB’s secondary key would read the primary key columns also, and used this property. On the other hand, the optimizer was not able to use the

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    More on cost-based choice between subquery Materialization and IN->EXISTS
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    In my previous post, I shared my finding that MySQL 5.6.7 does not make a cost-based choice between Materialization and IN-to-EXISTS strategies for subqueries.

    It turns out I was wrong. As Guilhem Bichot has blogged here, he has implemented cost-based choice between Materialization and IN->EXISTS in MySQL 5.6.7. Igor Babaev also wrote about the topic, and covered the reasons I didn’t see the feature - it isn’t mentioned in the documentation, development process at Oracle is quite closed, and the feature didn’t work for a basic example that I have tried.

    Let’s try to focus on the technical part of it. Looking at the source code, I see that

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    Swedish MySQL Users Group Meeting
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    Stockholm will host the Swedish MySQL Users Group on November 21st and the details can be found at http://www.facebook.com/events/468752256510179/

    We will talk about news from MySQL Connect, which was a few weeks ago, especially if 5.6RC course! * We will have a review of partitioning with a developer who has worked with just that. * Our last point is a review of a beloved children – character sets in MySQL. One common source of headaches.

    Two Cons against NoSQL. Part I.
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    Two cons against NoSQL data stores read like this: 1. It’s very hard to move data out from one NoSQL to some other system, even other NoSQL. There is a very hard lock in when it comes to NoSQL. If you ever have to move to another database, you have basically to re-implement a lot [...]
    On Eventual Consistency– Interview with Monty Widenius.
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    “For analytical things, eventual consistency is ok (as long as you can know after you have run them if they were consistent or not). For real world involving money or resources it’s not necessarily the case.” — Michael “Monty” Widenius. In a recent interview, I asked Justin Sheehy, Chief Technology Officer at Basho Technologies, maker [...]
    On Eventual Consistency — An interview with Michael Monty Widenius.
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    “For analytical things, eventual consistency is ok (as long as you can know after you have run them if they were consistent or not). For real world involving money or resources it’s not necessarily the case.” — Michael “Monty” Widenius. In a recent interview, I asked Justin Sheehy, Chief Technology Officer at Basho Technologies, maker [...]
    Slides and Other Files From My Hands-On Labs at MySQL Connect 2012
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    First of all a big thank you to all of you who attended my two Hands-On Labs (HOL) session at this year’s MySQL Connect. I ended up doing two sessions as there was a last minute cancellation, so in addition to the previously announced session about the Performance Schema, I also did an introduction to MySQL.

    The slides and the workbook for the Performance Schema session will become available from the official Oracle OpenWorld/MySQL Connect catalog, but you can also get the files from my blog which for the Performance Schema

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    Austin MySQL Meetup on Monday
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    The Austin MySQL Meetup is this Monday 7PM sharp at the Oracle office at 5300 Riata Park Court Building B. Please RSVP so we can order enough pizza!

    Comparison of subquery optimizations in MySQL 5.6 and MariaDB 5.5
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    MySQL 5.6 is now RC, I suppose this means that all features that were intended to be in release are pushed, so it’s time to take a look and see what’s going to be in MySQL 5.6 GA.

    I decided to look at subquery optimizations and compare them to what we’ve got in MariaDB 5.3/5.5. In case you don’t know, subquery optimizations in MySQL 5.6 and MariaDB come from a common ancestor - MySQL 6.0 alpha, which was released in spring 2009 and then abandoned because there were too many unstable features pushed into it.

    Then, both MariaDB team and Oracle salvaged subquery code out of the 6.0 mess, and worked to get it in shape for release. MariaDB released its results in GA quality in April 2012 as MariaDB 5.3, which was quickly followed by MariaDB 5.5.


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    Scaling MySQL and MariaDB to TBs: Interview with Martín Farach-Colton.
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    “While I believe that one size fits most, claims that RDBMS can no longer keep up with modern workloads come in from all directions. When people talk about performance of databases on large systems, the root cause of their concerns is often the performance of the underlying B-tree index”– Martín Farach-Colton. Scaling MySQL and MariaDB [...]
    October 8th — North Texas MySQL Users Group Meeting
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    Last Month the Verizon folks asked for a presentation on MySQL Replication and so we will have one on Monday October 8th.  MySQL Replication is easy to setup, reliable, and MySQL 5.6 brings some new features such as Global Transaction Identifiers.  So some learn the basics and learn the new features. 

    Starts at 5:00 PM! Please do not be late as the doors lock at 5PM and we will have to send someone to check on you!

    Refreshments will be served!

    Dallas – Irving Connection
    6031 Connection Drive
    Suite 900
    Irving, TX 75039
    Phone +1.972.652.8000

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