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Displaying posts with tag: mariadb (reset)

MariaDB 10.1.1: Compound statements
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Every now and then there is a need to execute certain SQL statements conditionally. Easy, if you do it from your PHP (or Java or whatever) application. But if all you have is pure SQL? There are two techniques that MariaDB and MySQL use in the mysql_fix_privilege_tables.sql script (applied by mysql_upgrade tool).

  • Create a stored procedure with IF statements inside, call it once and drop it. This requires the user to have the CREATE ROUTINE privilege and mysql.proc table must exist and be usable (which is not necessarily true — we’re doing it from mysql_upgrade, right?).
  • Use dynamic SQL, like
    SET @str = IF (@have_csv = 'YES',
                   'CREATE TABLE IF NOT EXISTS general_log (
                      event_time TIMESTAMP(6) NOT NULL,
                      user_host MEDIUMTEXT NOT NULL,

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    MariaDB 10.1.1: no more .frm’s for performance_schema tables
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    Yes! In MariaDB 10.1.1 tables in PERFORMANCE_SCHEMA do not use .frm files. These files are not created, not read — in fact, PERFORMANCE_SCHEMA tables never touch the disk at all.

    This became possible due to a lesser-known feature of MariaDB — new table discovery (“old table discovery” was implemented in MySQL for NDB Cluster in 2004), implemented in MariaDB 10.0.2. Instead of reading and parsing .frm files, MariaDB simply asks PERFORMANCE_SCHEMA table, what structure it has, and because these tables always have a fixed structure, the table directly returns it to MariaDB with no need for any external data dictionary.

    It also means, you never need to upgrade PERFORMANCE_SCHEMA tables, they

      [Read more...]
    MariaDB 10.1 Brings Compound Statements
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    A very old post of mine in 2009, MySQL’s stored procedure language could be so much more Useful suggested that it would be nice if MySQL could be adapted to use compound statements directly from the command line in a similar way to the language used for stored procedures. I’ve just seen that this seems to be possible now in MariaDB 10.1. See the release notes.

    I now need to look at this. So thanks, it looks like this feature request is now available.

    Integrating ClusterControl with FreeIPA and Windows Active Directory for Authentication
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    October 17, 2014 By Severalnines

    Integrating ClusterControl with a corporate LDAP directory is a common task for many IT organizations. In an earlier blog, we showed you how to integrate ClusterControl with OpenLDAP. In this post, we will show you how to integrate with FreeIPA and Windows Active Directory. 

     

    How ClusterControl Performs LDAP Authentication

     

    ClusterControl supports up to LDAPv3 protocol based on RFC2307. More details on this

      [Read more...]
    Ignoring the lost+found Directory in your Datadir
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    I still get asked about the lost+found directory enough, and so I wanted to provide a current update.

    The lost+found directory is a filesystem directory created at the root level of a mapped drive. Thus this is common to see if you create your mysql datadir at the root level of a mapped drive.

    In the past, you could ignore it, if it wasn’t too problematic for you, or you could move your datadir down a level, and then it wouldn’t be created in the datadir anymore.

    However, there is now the –ignore-db-dir option. It is actually not too new (it’s been in MariaDB since 5.3.9 and 5.5.28, and in MySQL as of 5.6.3), but I don’t think many are too familiar with it.

    But when you do run into this problem, some/many would prefer to add a single line to the config file rather than move the datadir.

    To do this, just

      [Read more...]
    How To Perform Basic Queries of MySQL / MariaDB on Fedora 20 For Newbies !!
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    Following Article Describes How To Perform Most Basic MYSQL / MariaDB Queries on Fedora 20? or How to Run MySQL on Fedora 20 ? Which is Latest Version of Linux Based Operating System Project. Last Operation of This Assignment also describes How to change MySQL 'Root' User password on Linux.
    It is also a part of 3rd Year, 5th sem Computer Engineering Academic Curriculum of Pune University. As PL 1 Subject. Group A, Assignment 1. It's Problem Statement And Solution is Given Below. You may also Checkout Database Management System complete syllabus & Tutorial of 5th sem subject called Database Management systems application.

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    MariaDB 10.1: Better query optimization for ORDER BY … LIMIT
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    For some reason, we’ve been getting a lot of issues with ORDER BY optimization recently. The fixes have passed Elena Stepanova’s scrutiny and I’ve pushed them to MariaDB 10.1. Now, MariaDB’s ORDER BY ... LIMIT optimizer:

    • Doesn’t make stupid choices when several multi-part keys and potential range accesses are present (MDEV-6402)
    • Always uses “range” and (not full “index” scan) when it switches to an index to satisfy ORDER BY … LIMIT (MDEV-6657)
    • Tries hard to be smart and use cost/number of records estimates from other parts of the optimizer (MDEV-6384, MDEV-465, MySQL
      [Read more...]
    MariaDB 5.5.40 Overview and Highlights
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    MariaDB 5.5.40 was recently released (it is the latest MariaDB 5.5), and is available for download here:

    https://downloads.mariadb.org/mariadb/5.5.40/

    This is a maintenance release, and so there are not too many big changes of note, just a number of normal bug fixes. However, there are a few items worth mentioning:

      [Read more...]
    A discovery - Index Condition Pushdown can cause a slowdown after all
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    MariaDB 5.5 and then MySQL 5.6 got Index Condition Pushdown (ICP) optimization (initially coded by yours truly). The idea of ICP is simple: after reading the index record, check the part of WHERE condition that can be computed using index columns, and only then read the table record. That way, we avoid reading table rows that don’t satisfy index condition:

    It seems apparent that ICP can never make things slower. The WHERE clause has to be checked anyway, and not reading certain records can only make things faster.

    That was what I thought, too, until recently Joffrey Michaie observed the contrary “in the wild”: we’ve got a real-world case where

      [Read more...]
    Database Automation - Private DBaaS for MySQL, MariaDB and MongoDB with ClusterControl
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    October 9, 2014 By Severalnines

    Installing, configuring, deploying databases and performing repetitive administrative tasks are all part of a DBA’s or sysadmin’s job. This can get pretty repetitive and overwhelming if you are part of a centralized IT team, running multiple databases for your organization’s different departments, or a managed hosting provider responsible for setting up and operating databases for external clients. One way to get out of this ‘manual, repetitive task’ business is through a Database as a Service (DBaaS).

    DBaaS is a way of delivering database functionality as a service to one or more consumers. A DBaaS platform would provide automated procedures for database deployment, monitoring,

      [Read more...]
    Showing entries 1 to 10 of 845 10 Older Entries

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