Since MySQL Shell 8.1, it’s even easier to create a logical backup of your MySQL instance and store it directly in Object Storage, an internet-scale, high-performance storage platform in Oracle Cloud Infrastructure (OCI).

MySQL Shell now offers the option of dumping to Object Storage Bucket using PAR (Pre-Authenticated Request).

Bucket Creation

The first step is to create an Object Storage Bucket in the OCI Console:

Let’s call it lefred-mysql-backups:

When created, we can click on the three-dots and create a new PAR:

To copy a MySQL server to another server or to the cloud, there are several ways.

We can distinguish between two different types of copy:

• physical copy
• logical copy

The physical copy is often the fastest. However, it requires some tools to ensure that you have a consistent online backup. For example, you can use MySQL Enterprise Backup (MEB).

Alternatively, it’s possible to use the CLONE plug-in to provision a new instance with existing data from a source server. This is my preferred approach.

Finally, the last physical solution is the use of a file system snapshot, but this requires the right infrastructure and even more care to have a consistent …

Sometimes it’s convenient to retrieve the user creation statement and to copy it to another server.

However, with the new authentication method used as default since MySQL 8.0, caching_sha2_password, this can become a nightmare as the output is binary and some bytes can be hidden or decoded differently depending of the terminal and font used.

Let’s have a look:

If we cut the create user statement and paste it into another server what will happen ?

We can see that we get the following error:

ERROR: 1827 (HY000): The password hash doesn't have the expected format.

How could we deal with that ?

The solution to be able to cut & paste the authentication string without having any issue, is to change it as a binary representation (hexadecimal) like this:

And then replace the value in the user create statement:

But there is an easier way. …

MySQL Shell is an advanced client and code editor for MySQL. In addition to the provided SQL functionality, similar to MySQL, MySQL Shell provides scripting capabilities for JavaScript and Python and includes APIs for working with MySQL. The X DevAPI enables you to work with both relational and document data, and MySQL Shell 8.0 is highly recommended for use with MySQL Server 8.0 and 5.7.

MySQL Shell includes utilities for working with MySQL. To access the utilities from within MySQL Shell, use the util global object, which is available in JavaScript and Python modes, but not SQL mode. These are the utilities to take a backup; let’s see some basic commands.

• util.dumpTables – Dump one or more tables from single database
• util.dumpSchemas – Dump one or more databases
• util.dumpInstance – Dump full instance
• util.loadDump – Restore dump

1. Single table …

Some times it’s important to know the size of a transaction, especially when you plan to migrate to a HA solution where by default transactions have a limited size to guarantee an optimal behavior of the cluster.

Today we will see the different possibilities to have an idea of the size of transactions.

First we need to split the transaction in two types:

• those generating data (writes, like insert, delete and update, DML)
• those only ready data (select, DQL)

To implement High Availability, only the first category is important.

Size of DML

To know the size of a DML transaction, the only possibility we have is to parse the binary log (or query the binlog event).

We need to check the binlog event from the binlog file and then calculate its size. To illustrate this, let’s try to find the transaction identified by a specific GTID: …

In this new article about how to find the info when using MySQL Database Service on Oracle Cloud Infrastructure, we will learn about the query accelerator: HeatWave.

With HeatWave, you can boost the performance of your MySQL queries, providing your applications with faster, more reliable, and cost-effective access to data.

HeatWave is a high-performance in-memory query accelerator for MySQL Database Service on Oracle Cloud Infrastructure. It is designed to accelerate analytics workloads (OLAP) and increase the performance of your MySQL databases by orders of magnitude. This is achieved through the use of in-memory processing, advanced algorithms, and machine learning techniques to optimize query performance. If identified by the optimizer, OLTP requests can also be accelerated using HeatWave.

Today we will try to answer the following questions:

1. Can I use HeatWave ?
2. Is HeatWave enabled ?
…

This is an update for MySQL 8 Stored PSM to add the ONLY_FULL_GROUP_BY mode to the global SQL_MODE variable when it’s not set during a session. Here’s the code:

/* Drop procedure conditionally on whether it exists already. */
DROP PROCEDURE IF EXISTS set_full_group_by;

/* Reset delimter to allow semicolons to terminate statements. */
DELIMITER $$

/* Create a procedure to verify and set connection parameter. */
CREATE PROCEDURE set_full_group_by()
  LANGUAGE SQL
  NOT DETERMINISTIC
  SQL SECURITY DEFINER
  COMMENT 'Set connection parameter when not set.'
BEGIN

  /* Check whether full group by is set in the connection and
     if unset, set it in the scope of the connection. */
  IF EXISTS
    (SELECT TRUE
     WHERE NOT REGEXP_LIKE(@@SESSION.SQL_MODE,'ONLY_FULL_GROUP_BY'))
  THEN
    SET @@GLOBAL.SQL_MODE := CONCAT(@@SESSION.sql_mode,',ONLY_FULL_GROUP_BY');
  END IF;
END;
$$

/* Reset the default delimiter. */
DELIMITER ;

You can call the …

Recently, I wrote three articles on how to analyze queries and generate a slow query log for MySQL Database Service on OCI:

• https://lefred.be/content/analyzing-queries-in-mysql-database-service/
• https://lefred.be/content/analyzing-queries-in-mysql-database-service-slow-query-log-part-1/
• https://lefred.be/content/analyzing-queries-in-mysql-database-service-slow-query-log-part-2/

In these post, we were generating a slow query log in text or JSON directly in Object Storage.

Today, we will see how we can generate …

You know how much I praise and like MySQL Shell but if like me, for you too, old habits die hard, I advise you to create these different aliases in your ~/.bashrc (or ~/.bash_aliases) file to force yourself to use MySQL Shell even for a small statement check:

alias mysql="mysqlsh --sql mysql://localhost"
alias mysqlx="mysqlsh --js mysqlx://localhost"

Of course you can specify the user you want, by default it uses the same user as the system one.

For example, if this is your test machine and you want to always use the root account (even if not recommended), you can specify it like this by modifying the URI:

alias mysql="mysqlsh --sql mysql://root@localhost"

Example:

So now when using mysql MySQL Shell is launched and it connects directly to localhost in SQL mode using the classic protocol.

With …

Full table scans can be problematic for performance. Certainly if the scanned tables are large. The worst case is when full table scans are involved in joins and particularly when the scanned table is not the first one (this was dramatic before MySQL 8.0 as Block Nested Loop was used) !

A full table scans means that MySQL was not able to use an index (no index or no filters using it).

Effects

When Full Table Scans happen (depending of the size of course), a lot of data gets pulled into the Buffer Pool and maybe other important data from the working set is pulled out. Most of the time that new data in the Buffer Pool might even not be required by the application, what a waste of resources !

You then understand that another side effect of Full Table Scans is the increase of I/O operations.

The most noticeable symptoms of Full Table Scans are:

• increase of CPU usage
• increase of …