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Displaying posts with tag: Oracle (reset)
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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Improved Logging Messages

Introduction

Logging is a very important diagnostic tool for understanding the behavior of the application as well as troubleshooting any issue with the application. Since MySQL Enterprise Backup (MEB) is a command line application, there is little interaction with the myriad of operations going on behind the scenes. Thus, logging messages are very important for knowing the progress of current operation as well as learning more about errors should they occur. The messages logged by MEB are written to the console and the log file as depicted in the following diagram, which looks similar to the Tee command in UNIX.


By default, MEB creates the log file in the default ‘<backup_dir>/meta’ directory with a name like MEB_<Date.time>_<operation_name>.log. For example – MEB created a log file with the name, …

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Optimistic Incremental Backup

MySQL Enterprise Backup Team is pleased to announce major improvements in incremental backup performance starting with release 4.1.

Introduction

The current incremental backup algorithm scans all the tables to gather changed pages even if very few tables are modified since the previous backup and thus results in a 'full-scan' incremental backup. This may result in increment backups requiring the same amount of time as full backup because it scans all the tables. The new algorithm aims to eliminate this extra time.

The new algorithm scans only those tables that have been modified since the previous backup. This algorithm relies on modification time, which is similar to an earlier improvement made for full backup. That full backup algorithm is known as optimistic full backup, hence new improvement is named …

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Improved Redo Log Copying During Backup

MySQL Enterprise Backup Team is pleased to announce redo log performance improvements during the backup operation starting with release 4.1. 

Introduction 

As explained in Redo Logging in InnoDB, redo logs are written to the redo log files in a circular fashion. Unless the MySQL server is idle, it continues to generate redo logs. MySQL Enterprise Backup (MEB) copies the redo logs from the redo log files to the ibbackup_logfile during a backup operation. MEB copies the redo logs in order to ensure that it does not miss any transaction while the physical backup is being done. MEB continues to copy the redo logs until it reads all the files from the data directory. If the redo log records are written faster than they can be processed by MEB, the backup operation fails with the following error.

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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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Group Replication: Shipped Too Early

This blog post is my overview of Group Replication technology.

With Oracle clearly entering the “open source high availability solutions” arena with the release of their brand new Group Replication solution, I believe it is time to review the quality of the first GA (production ready) release.

TL;DR: Having examined the technology, it is my conclusion that Oracle seems to have released the GA version of Group Replication too early. While the product is definitely “working prototype” quality, the release seems rushed and unfinished. I found a significant number of issues, and I would personally not recommend it for production use.

It is obvious that Oracle is trying hard to ship technology to compete with …

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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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How does a relational database work

Introduction While doing my High-Performance Java Persistence training, I came to realize that it’s worth explaining how a relational database works, as otherwise, it is very difficult to grasp many transaction-related concepts like atomicity, durability, and checkpoints. In this post, I’m going to give a high-level explanation of how a relational database works internally while … Continue reading How does a relational database work →

MySQL Group Replication vs. Multi Source

In my previous post, we saw the usage of MySQL Group Replication (MGR) in single-primary mode. We know that Oracle does not recommends using MGR in multi-primary mode, but there is so much in the documentation and in presentations about MGR behavior in multi-primary, that I feel I should really give it a try, and especially compare this technology with the already existing multiple master solution introduced in 5.7: multi-source replication.

Installation

To this extent, I will set up two clusters using MySQL-Sandbox. The instructions for MGR in …

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Powerful MariaDB exports using MyMDBDump

You can export data from MariaDB using mysqldump and a bunch of other tools, but if you need really flexible output format, this might not be what you need. Instead, give MyMDBDump a try. This tool will export data just like mysqldump, but the output format is a lot more flexible. I urge you to test it and check out the documentation, but some if the features are, in short:

  • Dynamic column support - Dynamic columns can be exported as binary, JSON or even as SQL, where I think the latter is a pretty unique feature.
  • Oracle export format - This exports data as INSERT statements, just like mysqldump, but in an Oracle friendly way.
  • MS SQL / SQL Server format - This exports data as SQL Server friendly INSERTs.
  • Binary data formats - Supporting plain binary, base64, hex and a number of more formats.
  • Transaction support.
  • JSON export support - Including embedding dynamic columns …
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