I recently published a blog post over on Medium
about the differences in 2 versions of the MySQL
COUNT() aggregate function: COUNT(*)
and COUNT(column_name or expression). I wanted to
share the post here with any readers who may be interested so
continue reading for more on this post…
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[Read more]Over the decades we have been reading the MySQL error log from the server system file, if there are any issues in MySQL or any unknown restart happened , generally we look at the mysql error log.
By default MySQL error log can be found in the default path
/var/log/mysqld.log , or it can be explicitly configured
using the variable log_error.
Few drawbacks using MySQL error log as FILE
To overcome the above issues , from MySQL …
[Read more]For MySQL, MyISAM and InnoDB storage engines are very popular. Currently, we are mostly using InnoDB engines for high reliability and high performance. Apart from those engines, we also have some other alternative engines and they have some nice features in them. In this blog, I am going to explain some of those engines, which I have listed below.
FEDERATED Storage Engine Overview:
Have you ever wondered what it takes to complete Percona Server for MySQL (PS), Percona XtraDB Cluster (PXC), and Percona XtraBackup (PXB) releases?
Let’s step back just a minute and talk about what Percona stands for. We believe we “stand on the shoulders of giants.” This means we respect our upstream sources and work to add value to the base products. Over time, new functionality is added. Much of this value-add was implemented on the 5.7 series and pulled forward to the 8.0 series. Each time we receive an upstream release, we must reapply these features to the release we receive. This process is what we call the Merge Process. …
[Read more]In the last post I covered some of the many reasons to migrate data from a spreadsheet to a database and now it is time to show how to do just that. Moving data from a spreadsheet into MySQL can actually be pretty simple in many cases. Now I will not mislead you by telling you that all cases are easy but there is an easy way to make this migration. And I highly recommend the following process when possible as it can save lots of time. More painful migrations will be covered in the future but this post is my favorite 'fast and easy' process.
This is a guide to taking data from a spreadsheet and easily moving that data into a MySQL database instance. The trick is the Import Wizard in MySQL Workbench that does a lot of the detail work for you. In a future post we will go into what you have to do when you are not …
[Read more]Transportable tablespaces were introduced in MySQL 5.6. Using this feature, we can directly copy a tablespace to another server and populate the table with data. This is a very useful feature for large tables. The transportable tablespace mechanism is faster than any other method for exporting and importing tables because the files containing the data just need to be copied to the target location using traditional Linux commands (cp, scp, rsync). Our post MySQL 5.6 Transportable Tablespaces best practices covers the best practices about transportable tablespaces. The feature also supports encrypted tablespaces, and in this article, I am going to explain how to use this feature with them.
Requirements
Below I am sharing my current setup and the requirements.
CodeIgniter’s Query Builder ORM has class methods for nearly any kind of database access/operation you can think of. In this post, I’ll cover some of the available methods for retrieving aggregate-level query results. The examples in this post map out Query Builder method chaining to produce results you would get from a raw MySQL query. Continue reading to see more…
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[Read more]Cross posting link Golang is a wonderful language. It's simple, and most of the time not confusing or surprising. This makes it easy to jump into library code and start reading and quickly understand what's going on. On the other hand, coming from other languages, there are a few features that would make our lives easier. We are building Vitess using mostly golang, and most of us are happy with this choice.
Starting a long time ago, we wanted to reproduce workload in a non-production environment, and there were different attempts to achieve that goal (Query Playback is just one of them). But there is another point of view, where you need to write your own workload to do so.
Both Have Pros and Cons
Reproduce Workload:
Pros:
Cons:
Custom Scripts:
Pros:
Due to CVE-2020-29488, Percona XtraBackup is modifying how xbstream handles absolute paths to prevent malicious file injections. Like the tar archiving utility, the new behavior removes the leading ‘/’ character and references to the parent directory.
Fixes are available in Percona XtraBackup versions:
>= 2.4.22
>= 8.0.23-16.0
For example, ../../../d1/../d2/h.txt will be saved
in the stream with the relative path ./d2/h.txt.
The updated function provides a warning when creating a stream with a file with an absolute path:
$ xbstream -c /tmp/data
xbstream: Removing leading '/' from member names
The function also will not extract …
[Read more]
