Dropping or removing an unused table from a database schema can be challenging. Even after triple checking that all of your apps have migrated away from querying the table, there may still be that one rogue script that accesses it.

Running the dreaded DROP TABLE statement can cause a host of unintentional problems if that table is still being used elsewhere. It completely erases the table definition, partitions, and the data in that table. Before you drop a table, you should double (or triple!) check when a table was last queried.

When was the table you want to drop last accessed?

You can manually check when a table was last accessed, but it's a bit complicated. The following query will show you the last time a table was written to, but not read:

 …

Learn about how we’re making it safer to drop tables and easier to detect if they’re still in use.

Introduction/FAQ

Question: I need to run a production-grade open source MySQL DB.

Answer: Percona to the rescue! Percona XtraDB Cluster (PXC) is an open source enterprise MySQL solution that helps you to ensure data availability for your applications while improving security and simplifying the development of new applications in the most demanding public, private, and hybrid cloud environments

Question: I forgot to mention that I need to run it on Kubernetes.

Answer: Percona to the rescue again! Percona Distribution for MySQL Operator based on Percona XtraDB Cluster contains everything you need to quickly and consistently deploy and scale Percona XtraDB …

Hey hey, OpenLampTech is back this week with another packed issue of the best MySQL, PHP, and LAMP stack content I am sharing from the web. Enjoy!

The Newsletter for PHP and MySQL Developers

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In OpenLampTech issue #36, we are looking at articles covering:

• PHP == vs === comparison operators
• MySQL ALTER TABLE
• Installing WordPress in a subdirectory.
• Why developers prefer Linux
• Getting your website ready to win
• And much much more

Get your brand, product, or service the attention it needs …

MySQL is the most popular open-source database and developers use it for building applications in various domains. Often developers need to apply machine learning to data stored in the database and in order to do so, they need to extract the data out of the database and then use machine learning libraries. MySQL HeatWave is […]

MySQL is the most popular open-source database and developers use it for building applications in various domains. MySQL HeatWave is a fully managed service for the MySQL database from Oracle and has built in support for machine learning (HeatWave ML). The user can use familiar SQL interfaces to invoke all the machine learning capabilities. In this article, we show you how to use HeatWave ML to build a ML model based on Census dataset to predict if an individual makes greater than 50k per year.

When we run a SELECT in a replica server and it returns a different result to the one we would have obtained had we queried the source server instead, due to changes in the dataset that have not yet been replicated or synchronized to the replica, we get what is known as a stale read. My colleague Marcelo has blogged about Stale Reads and How to Fix Them before.

The need to avoid stale reads is a constraint that leads people into migrating to Percona XtraDB Cluster (PXC) / Galera Cluster or, more recently, Group Replication. I am focusing on PXC and Galera in this short blog post, which, similar to Group Replication, implements not exactly a synchronous replication model but what is commonly referred to as a …

In this blog, I explain how to recover from a replication failure caused by a corrupted relay log file.

MySQL replica stores data received from its source binary log in the relay log file. This file could be corrupted due to various reasons, mostly hardware failures. If this happens, replication will stop working, and the error log on the replica will have entries similar to:

2022-05-12T12:32:07.282374Z 2 [ERROR] Error in Log_event::read_log_event(): 'Event too small', data_len: 0, event_type: 0
2022-05-12T12:32:07.282386Z 2 [ERROR] Error reading relay log event for channel '': slave SQL thread aborted because of I/O
...
2022-05-12T12:32:07.282396Z 2 [ERROR] Slave SQL for channel '': Relay log read failure: Could not parse relay log event entry. The possible reasons are: the master's binary log is corrupted (you can check this by running 'mysqlbinlog' on the binary log), the slave's relay log is corrupted (you can check this by running …

Introduction This is the fourth in a series of blogs that detail how to setup and use a LAMP Stack that makes use of MySQL HeatWave in the Oracle Cloud.   Predicates for completing the tasks in this blog You will need to have completed Parts 2 and 3 of this series of blogs. You […]

Introduction This is the third in a series of blogs that detail how to setup and use a LAMP Stack that makes use of MySQL HeatWave in the Oracle Cloud.   Predicates for completing the tasks in this blog You will need to have completed Part 2 of this series of blogs and gathered the […]