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Displaying posts with tag: Technical Track (reset)
Asynchronous Replication from MySQL Cluster

MySQL Cluster is a highly available, distributed, shared-nothing database with very interesting performance characteristics for some workloads. Among other features, it supports automatic sharding and allows us to bypass the SQL layer if we don’t need it, via the NDB API (which in my eyes, makes it one of the few transactional nosql databases out there).

In this post, I’ll describe how we can set up replication from MySQL Cluster into a standalone MySQL server using Innodb as the storage engine.

Introduction

There are a few reasons to set up replication between MySQL Cluster and a non-NDB based MySQL server. These reasons include (but are not limited to): the need …

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Log Buffer #507: A Carnival of the Vanities for DBAs

This Log Buffer edition covers Oracle, SQL Server and MySQL blog posts with a touch of Cloud.

Oracle:

Provisioning EBS on Oracle Cloud: Latest Enhancements

ORA-54002 when trying to create Virtual Column using REGEXP_REPLACE on Oracle 12cR2

Business rules, common sense and query performance

Problem with V$RECOVERY_AREA_USAGE view and FRA space not being reclaimed

Updated …

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Log Buffer #506: A Carnival of the Vanities for DBAs

This Log Buffer Edition covers blog posts from Oracle, SQL Server and MySQL.

Oracle:

12cR2 new features for Developers and DBAs

Adding Attachments to Deliveries in Order Information Portal

Database 12c Release 2 available for download

Let’s Start with Oracle Database 12c Release 2

In an Oracle data Guard Environment Log Network Server (LNS) Process …

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Log Buffer #505: A Carnival of the Vanities for DBAs

This Log Buffer Edition searches through various blogs of Oracle, SQL Server and MySQL and picks a few contemporary ones.

Oracle:

Comma separated search and search with check-boxes in Oracle APEX

Once you have defined your users for your Express Cloud Service, all users with the role of Database Developer or higher can access the database Service Console.

Big Data Lite 4.7.0 is now available on OTN!

Install and configure Oracle HTTP Server Standalone

Can I …

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Log Buffer #504: A Carnival of the Vanities for DBAs

This edition of Log Buffer covers Oracle, Microsoft SQL Server, and MySQL.

Oracle:

Data Pump or Data Pain Part02 – tablespace/user

Monday Spotlight: It’s About Security – Oracle Exadata SL6

0001_specify_date_format_mask.md copy

OGG Custom Adapters: How to include a unique identifier for …

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MySQL may return results in non-deterministic order with ‘order by’

Whenever we want a query’s results sorted, you may think of using the clause “order by.” You are correct: most of the time, MySQL will return the results in expected order with “order by.”

Be careful, though. Sometimes MySQL may return results in the non-deterministic order even with “order by.”

Indeed, if a query is ordered by a non-unique column, it may return results in an unexpected order. I tested the below example on MySQL 5.1.73, 5.5.54 and 5.6.19 and got the same result. However, when I applied the same example on MySQL 5.7.17, it returned the results in an unexpected order differently.

Follow me step-by-step and see how MySQL returns results in a non-deterministic order. Step 1-4 is for MySQL 5.1.73, 5.5.54 and 5.6.19, Step 5 is for MySQL 5.7.17. After the example, I will explain the reason behind this output.

Step 1. Create the table as …

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Customizing pt-stalk to Capture the Diagnostics Data You Really Need

Valeriy Kravchuk’s great recent post on using oprofile to profile MySQL mentioned how pt-stalk, the script from Percona Toolkit to capture diagnostics data based on a detected condition, currently does not support the new operf comand, and relies instead on the deprecated and soon to be removed, opcontrol.

Fortunately, in the Open Source world, we deal with these situations by contributing, and this seemed a simple enough change that I could get a PR ready quickly and reply …

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Log Buffer #503: A Carnival of the Vanities for DBAs

This Log Buffer Edition covers Oracle, SQL Server, and MySQL.

Oracle:

IaaS offers us elastic compute, elastic storage and network services. This allows you to run any workload in the cloud, cheaply and performantly.

Contextual Event API Improvements in ADF 12.2.1.x

Network access to Ubuntu Virtual Box VM from host laptop

Getting the most out of your Oracle database processor license …

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Log Buffer #502: A Carnival of the Vanities for DBAs

This Log Buffer Edition covers Oracle, SQL Server and MySQL.

Oracle:

EBS 12.1 Data Masking Template Certified with EM 13c

Oracle E-Business Suite Adapter and Integration Cloud Service

Oracle VAR_SAMP Function with Examples

Cloud Data Warehousing: Is it for real?

Using APEX_ERROR to manage custom error messages

SQL Server:

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Log Buffer #501: A Carnival of the Vanities for DBAs

This Log Buffer Edition covers Oracle, SQL Server and MySQL blog posts.

Oracle:

Will the FPDS-NG v 1.5 Upgrade In April 1st 2017 impact Contract Lifecycle Management (CLM)?

Real-Time Materialized Views in #Oracle 12c

Simplifying your data validation code with Database 12.2

Oracle VSIZE Function with Examples

Fixing PRVF-0002 : Could not retrieve local nodename

SQL Server:

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