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Displaying posts with tag: MySQL 5.7 (reset)
Easy Execution of Dynamic Queries with the sys Schema


When you write stored procedures in MySQL, you sometimes need to generate queries on the fly, for example as you process the result of another query. This is supported using prepared statements. This blog explores how you can take advantage of the sys schema to simplify the use of dynamic queries.

Executing a query using the sys.execute_prepared_stmt() procedure.

The sys schema includes several stored procedures and functions as well as views to make the database administrator’s life easier. One of these is the

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The Format for Timestamps in MySQL Logs


MySQL changed the timestamp format in the log files in MySQL 5.7. Since then, I have a few times seen questions about the new format, and how to change the time zone that is used. Latest in a comment to my blog about log_slow_extra in 8.0.14, where the question was what T and Z in the timestamp (for example 2019-01-31T07:24:06.100447Z) means. In this blog, I will discuss the timestamp format and show you how you can change the time zone used.

Examples of the timestamps from the MySQL error log when restarting MySQL (click to enlarge).
The MySQL 5.7 Change

In MySQL 5.7 it was decided to make two …

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Monitoring your 5.7 InnoDB cluster status

Recently we had a customer who came to us for help with monitoring their InnoDB cluster setup. They run a 5.7 InnoDB cluster and suffered from a network outage that split up their cluster leaving it with no writeable primaries. As part of their incident followup, they asked us for methods to monitor this cluster.

I had tested before with InnoDB clusters (in both 8.0 and 5.7 variants) and I was confident that we could parse the cluster node “role” (read-write aka primary vs. read-only aka secondary) from the performance_schema tables. As it turned out, this feature is not in 5.7 but only 8.0. However, the docs on this are wrong for 5.7 as these docs suggest that the performance_schema.group_replication_members table would show PRIMARY and SECONDARY role of each cluster node. I have submitted a …

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ProxySQL Series: MySQL InnoDB Cluster balancing ( using config file )

Introduction –

                     At Mydbops we are exploring the latest MySQL technologies . Recently i was worked for one of our client the project. The requirement is setting up a three node InnoDB cluster with 3 node ProxySQL cluster . During my ProxySQL configuration, i discovered that the ProxySQL group replication host groups are not loading from ProxySQL config file . Then i reached the ProxySQL official website and found that they are already have the bug for this issue and provided the fix as well ( BUG #1050 ). The fixed version is ProxySQL 1.4.9 .

                   I just had the interest to write the blog about this behaviour, as …

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Delayed Replication with Amazon RDS

Delayed replication” is one of the important features which were being supported in MySQL from 5.6 for a very long time. This induces an intentional lag in the slave, making it lag by the defined time interval.

For a long time this was not available with the RDS version of MySQL provided by AWS, Recently from the version 5.6.40, 5.722 and later versions this feature is available with all the regions.

I will give a small intro on Amazon RDS, Which is DBAAS provided by Amazon, where you will be given an end-point for all your DB operations and major of admin task of server and DB is taken care by Amazon, To know more you can view our presentation here

In this blog, I will demonstrate, how to have a delayed slave with Amazon RDS for MySQL

Note: If you are …

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GH-OST for MySQL Schema Change.

Schema change is one of the crucial tasks in MySQL with huge tables. Schema change can cause locks.

What is gh-ost?

                         gh-ost is a triggerless online schema change for MySQL by Github Engineering .It produces light workload on the master during the schema changes . We need online schema change to alter a table without downtime (locking) in schema change is the most widely used tool for making changes in the is just an alternative to pt-online schema change.

Why we have to use gh-ost?

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Replication Monitoring with the Performance Schema


The traditional way to monitor replication in MySQL is the SHOW SLAVE STATUS command. However as it will be shown, it has its limitations and in MySQL 5.7 and 8.0 the MySQL developers have started to implement the information as Performance Schema tables. This has several advantages including better monitoring of the replication delay in MySQL 8.0. This blog discusses why SHOW SLAVE STATUS should be replaced with the Performance Schema tables.

The Setup

The replication setup that will be used for the examples in this blog can be seen in the following figure.

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Shutdown and Restart Statements


There are various ways to shutdown MySQL. The traditional cross platform method is to use the shutdown command in the mysqladmin client. One drawback is that it requires shell access; another is that it cannot start MySQL again automatically. There are platform specific options that can perform a restart such as using systemctl on Linux or install MySQL as a service on Microsoft Windows. What I will look at here though is the built in support for stopping and restarting MySQL using SQL statements.

Photo by …

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Replicating data from MySQL to Oracle

In our work, We used to get a lot of requirements for replicating data from one data source to another.Previously I wrote replication from MySQL to Red-shift.

In this blog I am going to explain about replicating the data from MySQL to Oracle using Tungsten replicator.

1.0. Tungsten Replicator :

It is an open source replication engine supports data extract from MySQL, MySQL Variants such as RDS, Percona Server, MariaDB and Oracle and allows the data extracted to be applied on other data sources such as Vertica, Cassandra, Redshift etc.

Tungsten Replicator includes support for parallel replication, and advanced topologies such as fan-in and multi-master, and can be used efficiently in cross-site deployments.

1.1.0. Architecture :

There are three major …

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MySQL 5.7.* and mysqli

After installing MySQL 5.7.22 and PHP 7.1.17 on Fedora 27, you need to install the mysqli library. You need to verify if the mysqli library is installed. You can do that with the following mysqli_check.php program:

Check mysqli Install<?php if (!function_exists('mysqli_init') && !extension_loaded('mysqli')) {
    print 'mysqli not installed.'; }
  else {
    print 'mysqli installed.'; }

You test preceding PHP program with the following URL in a browser:


If the mysqli program isn’t installed, you can install it as follows by opening the yum interactive shell:

[root@localhost html]# yum shell
Last metadata expiration check: 1:26:46 ago on Wed 22 Aug 2018 08:05:50 PM MDT.
> remove php-mysql
No match for argument: php-mysql
Error: No packages marked for removal.
> install php-mysqlnd
> …
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