The article covers the basic syntax of a MySQL SELECT statement and provides examples that show how to use a MySQL SELECT statement to retrieve data from tables. The primary task in database management is writing and executing queries – commands for retrieving and manipulating data in databases. Users describe the tasks via these queries, […]
The post MySQL SELECT Statement Basics appeared first on Devart Blog.
Where I work, we are using MySQL a lot. The databases are being organized in replication hierarchies, and each hierarchy is a tree topology with a single primary and a number of intermediate replicas.
Replication is a tree managed by Orchestrator
We are using MySQL orchestrator to manage the replication topology.
MySQL Orchestrator shows a typical replication hierarchy. Each color indicates a different data center/availability zone. Replication is a tree, from the primary to per-AZ intermediate replicas for fan-out to leaf replicas. Clients connect to the primary for writing, and to the leaf replicas for reading. Special instances exist as clone sources and backup instances.
The diagram above is the view presented by …
[Read more]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 …
[Read more]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
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.
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 […]
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]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.
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 …
