I recently learned of some odd behavior using MySQL BETWEEN operator queries, filtering by a DATETIME column. I wrote about this over on Medium so I am sharing the post for any readers here who are interested…
Image by _Alicja_ from Pixabay
Self-Promotion:
If you enjoy the content written here, by all means, share this blog and your favorite post(s) with others who may benefit …
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The students needed yet another example of LEFT
JOIN, RIGHT JOIN, and FULL JOIN
syntax (by combining a left and right join with the UNION set
operator). To that end, I put this set of examples together.
The example also shows how to order the result set from a derived
table with the UNION operator. It uses the
WITH clause to build a Common Table Expression
(CTE), which allows the query to order the UNION set
operator’s product based on the left and right join queries. It
uses a CASE statement to order the result sets. The
left_table is the parent table and the
right_table is the child table in the relationship,
which means the right_table holds a
left_id foreign key column that lets you connect
matching rows in the left_table.
You build the little model with the following …
[Read more]When organizing things helps to simplify life.
In the previous article, we start to explore dynamic privileges and the interaction with static ones. We also saw how to remove SUPER privilege from a DBA account.
What we did was go by subtraction. But in real life, we should act differently. We should ADD only what is really needed for the account to work correctly.
Adding privilege one by one, and for each user is problematic given the level of interaction they may have, and also prone to mistakes.
Instead, we can use ROLES to group, assign, and revoke the correct privileges in a much easier way.
This is becoming even more important in MySQL with the advent of dynamic privileges.
What should we do to correctly use ROLES? Well first of all design. …
[Read more]When trying to make things better, make our life very complicated.
I was working on a Security Threat Tool script, when I had to learn more about the interaction between static and dynamic privileges in MySQL 8.
Dynamic privileges is a “new” thing added in MySQL 8 to easily extend the privileges definition, and at the same time to provide more granularity. For instance the FLUSH operation now has dedicated Privileges and by scope.
Dynamic privileges are assigned at runtime. Most of them are active when the server starts. But they can also change in respect to the components or plugin when activated. (https://dev.mysql.com/doc/mysql-security-excerpt/8.0/en/privileges-provided.html#privileges-provided-dynamic)
Static privileges are the classical privileges available in MySQL …
[Read more]When trying to make things better, make it very complicated.
I was working on a Security Threat Tool script when I had to learn more about the interaction between static and dynamic privileges in MySQL 8.
Dynamic privileges is a “new” thing added in MySQL 8 to easily extend the privileges definition, and at the same time to provide more granularity. For instance, the FLUSH operation now has dedicated Privileges and by scope.
Dynamic privileges are assigned at runtime. Most of them are active when the server starts. But they can also change with respect to the components or plugin when activated. ( …
[Read more]When organizing things helps to simplify life.
In the previous article we start to explore dynamic privileges and the interaction with the static ones. We also saw how to remove SUPER privilege from a DBA account.
What we did was go by subtraction. But in real life, we should act differently. We should ADD only what is really needed for the account to work correctly.
Adding privilege one by one, and for each user is problematic given the level of interaction they may have, and also prone to mistakes.
Instead we can use ROLES to group, assign and revoke the correct privileges in a much easier way.
This is becoming even more important in MySQL with the advent of dynamic privileges.
What should we do to correctly use ROLEs? Well first of all …
[Read more]The practice of running databases in containers continues to grow in popularity. As a Technical Account Manager at Percona, I get asked regularly about our Percona Distribution for MySQL Operator. Additionally, I’m asked what I’m seeing in the industry in terms of adoption. In most cases, the questions stem around new deployments. Our DBaaS tool (currently in Technical Preview) makes launching a new cluster in a Kubernetes deployment trivial.
Once the operator completes and verifies the setup, the UI displays the endpoint and credentials and you are on your way. Voila! You now have a cluster, behind a load balancer, that you can access from within your k8s cluster or …
[Read more]In the previous release of our Percona Distribution for MySQL Operator, we implemented one interesting feature, which can be seen as “self-healing”: https://jira.percona.com/browse/K8SPXC-564.
I do not think it got enough attention, so I want to write more about this.
As it is well known, a 3-node cluster can survive a crash of one node (or pod, in Kubernetes terminology), and this case is very well handled by itself. However, if there is a problem with 2 nodes at the same time, this scenario is problematic for Percona XtraDB Cluster. Let’s see why this is a problem.
First, let’s review if the first node goes offline:
In this case, the cluster can continue work, because Node 1 and Node 2 figure out …
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In this blog, we will discuss about how to setup MySQL NDB
Cluster replication in a more secure way with the help of binary
log and relay log encryption and a secure connection. These
measures protect binary log dat in transit and at rest.
Let’s create two MySQL NDB Clusters with the following
environment, Here, one will be termed as ‘source’ cluster and the
other one will be termed as ‘replica’ cluster.
Step 1: Start both of the Clusters
Let’s start both the source cluster and replica cluster but do
not start the MySQLD servers from both the clusters as we want to
modify their configuration first.
…
In my previous post Back From a Long Sleep, MyDumper Lives!, I told you that Fast Index Creation was in the queue and (after fixing several bugs) it will package in release 0.10.7 next month. But why am I so excited about it? Well, this feature opens new opportunities, what I’m going to call Restore Strategies.
In the Past…
In the past, the only option was to first restore the table definition and then insert the data rows in two simple steps. On tables with millions of rows, we already know why it takes more time as it inserts in the clustered index and in the secondary index, instead of building the secondary indexes after the data has been inserted, as myloader is able to do now.
Nowadays, we have the option to do it, in …
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