Welcome to this week’s OpenLampTech newsletter. I have many great articles curated for you this week. Thank you for reading and please share the publication with others.

The Newsletter for PHP and MySQL Developers

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In OpenLampTech issue #47, we are looking at articles covering:

• MySQL Spatial data types
• Build a blog backend with Laravel
• 10 Linux command-line operators
• MySQL row locking
• And much more

Want to support the OpenLampTech publication? Easy enough.

Head on over to …

Statement Digest in MySQL 

https://dev.mysql.com/doc/refman/8.0/en/performance-schema-statement-digests.html

The parser is also used by the STATEMENT_DIGEST_TEXT() and STATEMENT_DIGEST() functions, which applications can call to compute a normalized statement digest and a digest hash value, respectively, from an SQL statement.

events_statement_summary_by_digest in Performance Schema contains information

…

in this tutorial, We’ll Learn how to fix MySQL ERROR 2002 Can’t connect to local MySQL server through socket ‘/tmp/mysql.sock. Normally, This issue will occur when you connect the MySQL server through the command line, you might encounter a MySQL ERROR 2002 as follows: mysql -uroot -proot ERROR 2002 (HY000): Can’t connect to local MySQL […]

The post ERROR 2002 : Can’t connect to MySQL server through socket appeared first on Phpflow.com.

Let’s continue our journey of deploying the MySQL Database System on OCI with Terraform.
This time we will see how we can use a backup (see [1] and [2]) as a source (initial data) for a new instance.

Within the oci_mysql_mysql_db_system it’s possible to define a source detailing how to provision the initial data of the db system.

Let’s deploy a new MySQL Database Instance using a manual backup we made earlier:

We can also find the backup’s ocid using the oci cli command:

 $ oci mysql backup list …

Today I would share a nice book related to MySQL 8.0 for our Chinese users.

The original title of this book by Scott Yao, is MySQL 8.0 运维与优化

I had the chance to read parts of the book before it was published to have my comment on the back cover.

This book is very detailed with many examples on how to administer a MySQL server.
It covers the new features of MySQL 8.0 and Scott illustrates perfectly how to take advantage of them.

Reading the book, it is obvious that the author is an experienced MySQL DBA and is sharing his experience that many junior DBAs can certainly benefit from.

This is a very technical book, as I like, I really recommend it to all Chinese people and I hope to see it translated into English too.

And finally I would thanks Scott for having sent to me a hard signed copy of the …

Recently I wrote an article on how to define a backup policy for MySQL Database Service in OCI using Terraform. We saw that it was possible to define tags (defined_tags and freeform_tags) in the backup_policy section of a oci_mysql_mysql_db_system resource.

However, it seems that these tags are never used for manual or automated backups in the MySQL Database Service backup process. In the strategy implemented on OCI, the backups inherit the tags from the MySQL DB system itself.

This means that if you want to have some custom tags on your backups, you need to specify them in the MySQL Database resource like this (on line 12):

resource "oci_mysql_mysql_db_system" "MDSinstance" {
    admin_password = var.admin_password
    admin_username = …

A few weeks back, we faced an issue in a replication environment for a Managed Services client:

LAST_ERROR_MESSAGE: Worker 2 failed executing transaction ‘UUID:GTID’ at master binlog.0012345, end_log_pos 98765; Error ‘Operation CREATE USER failed for ‘test_user’@’10.10.10.10” on query. Default database: ‘mysql’. Query: ‘CREATE USER ‘test_user’@’10.10.10.10’ IDENTIFIED WITH ‘mysql_native_password’ AS ‘************”

After some initial investigation, we noticed that the user in the replica didn’t exist! Was MySQL going crazy? But then the customer mentioned they had the following error in the primary before being able to execute the query successfully:

root@localhost [mysql]> CREATE USER 'test_user'@'10.10.10.10' identified WITH 'mysql_native_password' BY …

If you watched Finding Poorly Designed Schemas and How to Fix Them you witnessed Marcos Albe use some very interesting queries. These queries let you find tables without primary keys, tables with non-integer primary keys, tables that do not use InnoDB, tables and indexes with the most latency, indexes that are 50% larger than the table, find duplicate indexes, and find unused indexes. As promised, they are below.

— Find tables without PK
SELECT t.table_schema,t.table_name,t.engine
FROM information_schema.tables t
JOIN information_schema.columns c
ON t.table_schema=c.table_schema
AND t.table_name=c.table_name
WHERE t.table_schema NOT IN (‘mysql’, ‘information_schema’, ‘sys’, ‘performance_schema’)
AND t.table_type = ‘BASE TABLE’
GROUP BY t.table_schema,t.table_name, t.engine
HAVING …

I recently had the chance to read in preview Bill Karwin‘s new book: SQL Antipatterns, Volume 1: Avoiding the Pitfalls of Database Programming.

This book is a rework of Bill’s best seller from 2010. The new book can be considered as the second edition and is updated with Bill’s latest observations about common mistakes.

The author took in consideration the feedback about the first edition.

This new edition is full of information for beginners but also for experts who will appreciate to see how antipatterns are solved and most of the time surely propose different approaches.

Each antipatterns are identified by their names like “jaywalking“, …

The subtitle of this post could have been “Review of an awesome MySQL event”.

I’ve been invited by the MySQL Italian team to deliver a session about MySQL Shell during the MySQL Day in Roma. This was the very first in person event by MySQL Italy since the pandemic.

The amount of attendees was large and we could feel the emotion and the enthusiasm of the audience. Everybody enjoyed to finally be together again and discus about MySQL.

The day started with a MySQL Overview by Andra Cazacu. She was very emotionalized to see how the room was packed.

I was really great to see all those people smiling, I could feel that people were very happy to be present at this event.

The Show Runner

After Andra, it was already the turn of the Italian Star: “il grande Marco Carlessi” !

Marco presented the latest news in MySQL:

• Multi Factor Authentication
• New …