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MySQL Aggregate Query using CodeIgniter’s Query Builder

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…

Image by Clker-Free-Vector-Images from Pixabay

Self-Promotion:

If you enjoy the content written here, by …

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Deep Dive: How to Easily Deploy MySQL Clusters With The Tungsten Cluster AMI

Read this blog to get a more in-depth understanding of what the Tungsten Cluster AMI is, how it works and how to use it in order to easily deploy MySQL database clusters and more.

Tags: MySQLClusteringtungsten clusteringdatabase clustertungsten cluster ami

Code generation in Vitess

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.

HTML5 Push Notification System Using Nodejs MySQL Socket.io

Real-time web/mobile application is becoming popular day by day. Services like Firebase and Pusher provides API’s and Services to develop effective real-time notification system for your mobile and web apps. We are not going to use these Services in this post; instead, we will develop an application that pops up a notification on a particular […]

Is a Session Analyzer a Good Tool to Simulate Real Traffic?

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:

  • Simple to implement
  • Ready to go

Cons:

  • Need to rebuild the environment each time

Custom Scripts:

Pros:

  • Possible to have a more realistic workload
  • You can reuse the environment
  • You can use Sysbench that allows you to change …
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CVE-2020-29488: Changes in How Absolute Paths are Handled in Percona XtraBackup xbstream

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 …

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MySQL Backup setup, automation using Holland, mysqldump on Ubuntu

This post will guide you to set up and automate the MySQL logical backups using mysqldump on Ubuntu Linux. We will set-up MySQL backup using mysqldump and automate it with…

The post MySQL Backup setup, automation using Holland, mysqldump on Ubuntu first appeared on Change Is Inevitable.

Table partitioning in MySQL NDB Cluster and what’s new (Part III)

Whats new in NDB Cluster 7.5 version (Contd.)

In cluster 7.5 the READ_BACKUP and FULLY_REPLICATED table features were added. These features are both designed to improve read performance and scalability, and can be set on a per-table basis. These features are fully implemented inside MySQL Cluster, and tables using these features support all of the normal MySQL Cluster features - secondary unique and ordered indexes, foreign keys, disk resident columns, replication etc. The read performance improvements do not require any special effort to take advantage of – MySQL Cluster automatically chooses the most efficient way to execute reads, whether issued over NdbApi, or via SQL, executed in MySQLD or pushed down for parallel execution in the data nodes.

READ_BACKUP:

Prior to 7.5, all Committed Read operations were routed to a primary replica of the table or index fragment to be read. The …

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Designing a Thread Pipeline for optimal database throughput with high IPC and low CPU cache misses

 There are a couple of questions about the blog post on automatic thread configuration in RonDB. Rather than providing an extensive answer in the comment section I thought it was better to answer the questions in a separate blog. In addition I performed a set of microbenchmarks to verify my expectations.


The first question was the following:


ScyllaDB also does something similar with execution stages for better instruction cache. Is this similar to what you're implementing for instruction cache on separating the threads?


The second question is:


I don't really get the functional separation of threads. To execute a query, your data will now go through a pipeline of …

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MySQL Transaction Scope

The idea of ACID transactions are a basic feature of SQL’s individual Data Manipulation Language (DML) commands, like the INSERT, UPDATE, and DELETE statements. Transactions across two or more tables are a natural extension of ACID compliance features provided by DML commands. However, they require a structured programming approach, like a store procedure or like API implemented in an imperative language.

Surprisingly, transaction management wasn’t covered well in Alan Beaulieu’s Learning SQL because he only provided pseudo code logic. While I thought troubleshoot some broken MySQL SQL/PSM logic would be a good learning experience for students, it wasn’t. So, I wrote this sample code to show how to achieve an all or nothing transaction across four tables.

The code for this example on transaction management lets you perform the important tasks necessary to effect transaction …

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