Last year, we asked you a few questions in a blog poll and we received a great amount of feedback. This year, we wanted to follow up on those same survey questions to see what may have changed over the last 12 months. So with that in mind, we’re hoping you can take a minute or so to answer the first survey question in this series: What Keeps You Up At Night? Is it fixing emergencies? Bad queries? Cost concerns? Inquiring minds want to know!

Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.

This poll question will be up for one month and will be maintained over in the sidebar should you wish to come back at a later date and take part. We look forward to seeing your responses!

I think it is often confusing to compare upstream MySQL and Percona Server for MySQL, and some helpful information can be found in the introductory notes. But what does that really mean for an ordinary DBA, especially if none of the known big extra features are important in a particular use case?

In this article, I would like to start a series of short blog posts highlighting small, often less known, but potentially useful features, available in Percona Server for MySQL. Let’s start with a relatively new feature.

Limit the disk space used by binary logs problem

Historically, dealing with binary logs and the disk space used by them was quite challenging. The only thing that let you control this is the …

Author: Robert Agar

The working life of a DBA is often centered on optimizing their systems to provide users with the best performance. There are many aspects of a MySQL implementation that can be tuned to increase its functionality. These improvements will result in a more efficient system and enhanced user experience.

One of the problems facing the DBA responsible for instituting performance tuning is to identify the particular areas to address that will impact the system in a positive manner. Approaching this task in a haphazard fashion is not advisable. Randomly modifying parameters is just as likely to cause further issues than to lead to performance gains. Luckily, there is a solution to this dilemma.

Conducting focused monitoring can be instrumental in enabling the DBA to pinpoint the source of performance degradation. Armed with this knowledge, informed decisions can be made regarding how …

Introduction In this article, we are going to test the MySQL 8 implementation of custom SQL CHECK constraints. Although the CHECK clause is a standard SQL feature, prior to MySQL 8.0.16, the clause was parsed and ignored, so this functionality could only be emulated via BEFORE INSERT and UPDATE triggers. Custom SQL CHECK constraints As I explained in this article, custom SQL CHECK constraints are very useful to ensure non-nullability constraints for JPA entity subclass-specific attributes when using the SINGLE TABLE JPA inheritance strategy. To understand the problem, consider we have the... Read More

The post MySQL 8 support for custom SQL CHECK constraints appeared first on Vlad Mihalcea.

In week 3 of our series, Benefits of SQL Diagnostic Manager for MySQL (formerly Monyog), we discuss how to identify and analyze problematic SQL queries using SQL Diagnostic Manager for MySQL. If you missed it, feel free to read our previous post on Agentless Monitoring and Cloud Readiness.

Find Problematic SQL Queries

MySQL and MariaDB currently lack advanced tools for profiling SQL queries (such as SQL Profiler of Microsoft’ SQL Server). While other monitoring tools for MySQL and MariaDB provide monitoring and advisory information on various system metrics, they do not pinpoint the problematic SQL queries. No amount of hardware upgrades and tuning of the parameters in the database server configuration file ‘my.cnf’ and the database server initialization file …

The CTO has issued the decree: “We are moving to the cloud!”  Great, so now what do we do? When it comes to migrating from on-premise to the cloud, there are many factors to consider and decisions that need to be made.  First (and probably most important) on that list: managed DBaaS or setup and manage our own infrastructure?

Type of Cloud

Managed DBaaS options are great but come with some limitations.  The main two questions that should be considered here are around staff/experience and current architecture/database design.  In cases where there is a very limited database (or operations) team, a DBaaS is a great choice. Much of the operational infrastructure is already in place with general best practices in place.  However, a big tradeoff comes around flexibility. In cases where the current infrastructure is complex (for reasons right or wrong), a DBaaS is definitely the wrong choice as you will be …

It’s bad practice to provide world-writable access to critical files in Linux, though we’ve seen time and time again that this is done to conveniently share files with other users, applications, or services. But with Xtrabackup, preparing backups could go wrong if the backup configuration has world-writable file permissions.

Say you performed a backup on a MySQL instance configured with data-at-rest encryption using the keyring plugin. On the backup directory, the generated backup-my.cnf contains these instructions to load this plugin that will be used by Xtrabackup while preparing the backup:

backup-my.cnf

[mysqld]
innodb_checksum_algorithm=crc32
innodb_log_checksum_algorithm=strict_crc32
innodb_data_file_path=ibdata1:12M:autoextend
innodb_log_files_in_group=2
innodb_log_file_size=1073741824
innodb_fast_checksum=false
innodb_page_size=16384
innodb_log_block_size=512
innodb_undo_directory=./
innodb_undo_tablespaces=0 …

MySQL has introduced the concept of functional index in MySQL 8.0.13. It is one of the much needed feature for query optimisation , we have seen about histogram in my last blog. Let us explore the functional index and its use cases.

For the below explanation, I have used a production scenario which has 16 core cpu, 32GB RAM and with MySQL version 8.0.16(Latest at the time of writing).

MySQL do support indexing on columns or prefixes of column values (length).

Example: 

mysql>show create table app_user\G
*************************** 1. row ***************************
Table: app_user
Create Table: CREATE TABLE `app_user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`ad_id` int(11) DEFAULT NULL,
`source` varchar(32) DEFAULT NULL,
`medium` varchar(32) DEFAULT NULL,
`campaign` varchar(32) DEFAULT NULL,
`timestamp` …

Quickly configure replication using DBdeployer [SandBox]
We might have different scenarios when we need a quick setup of replication either between the same version of MySQL (Like 8.0 --> 8.0) or between the different version of MySQL (Like 5.7 --> 8.0) to perform some testings. 

Here in this blog post, I will explain how we can create our replication lab setup quickly using the virtual machine and DBdeployer tool. 

Let's see, how to create replication between the same version and different version of MySQL using DBdeployer step by step. 

Create CentOS VM Please find my …

What are things you must consider before using Galera Cluster Streaming Replication ? 

In Streaming Replication, the node breaks the transaction into fragments, then certifies and replicates them on the slaves while the transaction is still in progress. Once certified, the fragment can no longer be aborted by conflicting transactions. Additionally, Streaming Replication allows the node to process transaction write-sets greater than 2Gb. So, How do you decide whether go with Galera Cluster Streaming Replication or not ? We caution our customers before choosing Galera Cluster Streaming Replication considering several limitations and costs attached to it (explained below the limitations of Galera Cluster Streaming Replication in this post). Even you have decided to proceed with Galera Cluster Streaming Replication, We recommend you to enable it only for a session-level and then only on specific transactions.

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