dasini.net – Diary of a MySQL expert

As the administrator of a cluster, among other tasks, you should be able to restore failed nodes and grow (or shrink) your cluster by adding (or removing) new nodes.
In MySQL, as a backup tool (and if your amount of data is not too big), you can use mysqldump a client utility that performs logical backups.
The results are SQL statements that reproduce the original schema objects and data.
For substantial amounts of data however, a physical backup solution such as MySQL Enterprise Backup is faster, particularly for the restore operation.
But this is the topic of my next blog post 🙂

Since 8.0.16, MySQL Server supports a –validate-config option that enables the startup configuration to be checked for problems without running the server in normal operational mode.
–validate-config can be used any time, but is particularly useful after an upgrade, to check whether any options previously used with the older server are considered by the upgraded server to be deprecated or obsolete.

Presentation of some of the new features of MySQL 8.0.16 released on April 25, 2019

Q: Validate an instance for MySQL InnoDB Cluster usage?

A: Use check_instance_configuration()

MySQL (really) supports CHECK CONSTRAINT since version 8.0.16.
In this article I will show you 2 things:
– An elegant way to simulate check constraint in MySQL 5.7 & 8.0.
– How easy & convenient it is to use CHECK constraints in 8.0.16.

In MySQL 8.0.16 the optimizer has improved again!
Comparisons of columns of numeric types with constant values are checked and folded or removed for invalid or out-of-rage values.
The goal is to speed up query execution.

MySQL InnoDB Cluster – HowTo #1 – Monitor your cluster

Q: How do I monitor the status & the configuration of my cluster?

A: Use status() or status({extended:true}) or status({queryMembers:true})?

MySQL 8.0 provides another way to handle JSON documents, actually in a “Not only SQL” (NoSQL) approach…
In other words, if you need/want to manage JSON documents (collections) in a non-relational manner, with CRUD (acronym for Create/Read/Update/Delete) operations then you can use MySQL 8.0!
Did you know that?

MySQL Enterprise Data Masking and De-Identification hides sensitive information by replacing real values with substitutes in order to protect sensitive data while they are still look real and consistent.

Since MySQL 5.7 one can put indexes on expressions, aka functional indexes, using generated columns. Basically you first need to use the generated column to define the functional expression, then indexed this column.

Quite useful when dealing with JSON functions, you can find an example here and the documentation there.

Starting with MySQL 8.0.13 we have now an easiest way to create functional indexes (or functional key parts as mentioned in the documentation) \o/

Let’s see how with a quick practical example.