This week we start talking about common schema by Shlomi Noach. Ear Candy is some caveats about GTIDs and replication, and At the Movies is using jQuery, AJAX and PHP to insert data into MySQL.

News
In the news, the OurSQL podcast will change to a monthly format after episode 200. We love doing the podcast, but it is very time consuming and production is expensive. We will still bring quality episodes, they will just be spaced further apart.

Common Schema
Common Schema Google Code page

Installation section of the common schema documentation.

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Introduction

Eventual consistency [1] is a consistency model, which is used in many large distributed databases. Such databases require that all changes to a replicated piece of data eventually reach all affected replicas. Furthermore, the conflict resolution is not handled in these databases, and the responsibility is pushed up to the application authors in the event of conflicting updates. Eventual consistency is a specific form of weak consistency: the storage system guarantees that if no new updates are made to the object, eventually all accesses will return the last updated value [1]. If no failures occur, the maximum size of the inconsistency window can be determined based on the factors such as communication delays, the load on the system, and the number of replicas involved in the replication scheme. We earlier in …

MySQL Enterprise Backup(MEB) has been widely used as the most efficient tool to take backups of huge databases. The storage of backups can be done on-premises – viz, local hard disk, external hard disk drives, network mounted disk. MEB can also stream backups to tape by supporting different Media Management Software like Symantec NetBackup, EMC2 and Oracle Secure Backup. Streaming of backups can also be done using 'ssh' to another machine.

As data keeps growing, instead of expanding the storage, database users are choosing to rely on the growing trend which is the Cloud Storage.

A few facts about Cloud Storage:

1. Offers off-premises storage with AAA(Anytime, Anywhere Access)
2. Sharing of data to make a collaborative effort.
3. Highly fault tolerant, durable and scalable and secure.
4. Cost-effective

To the benefit of our MySQL database users, Mysql …

Most MySQL-ers quickly learn to move logs out of the data directory. Hopefully the logs are being written to a different disk, on a different controller than where the data is being kept. The horror of finding you database server dead to the world because the single partition used for everything was filled up by the error log should be a thing of the past. MySQL 5.7 will give DBAs better control of log files,

As of 5.7.2, we have gained the ability to control the verbosity of error messages with log_error_verbosity. This system variable controls verbosity in writing error, warning, and note messages to the error log. A value of 1 provides errors only, 2 adds warnings, and 3 adds notes. The default value is 3. And with that with level 3, aborted connections and access-denied errors for new connection attempts are written to the error log.

The good ol’ log_warnings is being deprecated in favor of the added …

We are pleased to announce that MySQL Enterprise Monitor 3.0.12 is now available for download on the My Oracle Support (MOS) web site. It will also be available via the Oracle Software Delivery Cloud in about 1 week. This is a maintenance release that includes a few new features and fixes a number of bugs. You can find more information on the contents of this release in the change log.

You will find binaries for the new release on My Oracle Support. Choose the "Patches & Updates" tab, and then choose the "Product or Family (Advanced Search)" side tab in the "Patch Search" portlet.

You will also find the binaries on the Oracle Software Delivery Cloud in approximately 1 week. Choose "MySQL Database" as the Product Pack …

I think that getting 128-bit types into MySQL would be good. There are a few use cases for this and right now we have to work around them. That should not be necessary.  While not essential they would make things easier. The headline is easy to understand, but is this really needed? First we need … Continue reading Time to get some 128-bit types into MySQL?

Section 6: "Profile a real case" 6.1 INTRODUCTION

Profiling & Debugging is an argument that would require an entire book, the aim of this(and the others) posts of this series is to give you the basic knowledge on how to work with these tools and techniques withing Eclipse. For instance if you want to learn to profile with OProfile you should study on the abundant and separate resources, you may start from: http://OProfile.sourceforge.net

6.2 ABOUT NAMING THE PROJECT

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Last week, yours truly has pushed a new feature into MariaDB 10.1 tree: ANALYZE statement.

The idea of this feature is to make it easy to compare query plan with query execution. ANALYZE statement will run the statement, and produce EXPLAIN-like output, where optimizer’s estimates are followed by numbers that were observed when running the query. The output looks like this:

Here,

• Next to rows there is r_rows column which shows how many records were read from the table.
• Next to filtered there is r_filtered column which shows which fraction of records was left after the part of the WHERE condition attached to the table was checked.

I think this should explain the feature. If you want more details, please refer to the KB article …

On July 16 I’ll be presenting my next webinar focusing on common mistakes committed by MySQL users.

How to Avoid Even More of the Common (but Deadly) MySQL Development Mistakes

“Why can’t I just save my data to a file?”

Using an SQL database seems so complex to get right, and for good reason. The variety of data-driven applications is practically limitless, and as project requirements change, we find ourselves taking shortcuts and adopting bad habits. But there are proven methods to understanding how to develop and manage data in a scalable and reliable way. This talk shows you some of these methods, including:

• How to optimize a database application with partitioning and sharding.
• How to avoid the secret security …

I had been involved with subquery optimizations fairly closely, but last week I was surprised to find out that MySQL 5.6 does not support derived table merging. This feature was among the subquery features in the abandoned MySQL 6.0. In MariaDB, it was finished and released as part of MariaDB 5.3/5.5. As for MySQL, neither MySQL 5.6, nor MySQL 5.7 has this feature.

So what is this “derived merge”? It’s simple to understand. When one writes complex queries, it is common to use FROM-clause subqueries as a way to structure the query:

select
  sum(o_totalprice)
from
  (select * from orders where o_orderpriority=’1-URGENT’) as high_prio_orders
where
  o_orderdate between ‘1995-01-01′ and ‘1995-01-07′

MySQL …