Introduction I read a very interesting article by Krešimir Nesek regarding MySQL result set streaming when it comes to reducing memory usage. Mark Paluch, from Spring Data, asked if we could turn the MySQL result set streaming by default whenever we are using Query#stream or Query#scroll. That being said, the HHH-11260 issue was created, and … Continue reading How does MySQL result set streaming perform vs fetching the whole JDBC ResultSet at once →
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MySQL-Sandbox installs the MySQL server in
isolation, by rejecting existing option files using the option
--no-defaults. This is usually a good thing, because
you don't want the initialization to be influenced by options in
/etc/my.cnf or other options files in default
However, such isolation is also a problem when you need to add
options during the initialization. One example is innodb-page-size, which can be set to many
values, but only if the server was initialized accordingly. Thus,
you can't set
innodb-page-size=64K in your
configuration file because the default value is different. It
would fail, as InnoDB would conflict.
About one month ago, the MySQL team at Oracle released MySQL 8.0, with a large list of changes. One of the most interesting features in the new release is also one that does not show up much, also because the team has gone to great length to keep most of its implementation hidden: the data dictionary.
What makes the data dictionary so interesting, despite its scarce visibility, is the effect that it has on performance. Up to MySQL 5.7, searching the information_schema was an onerous operation, potentially crippling the system. In MySQL 8.0, the same operations are …[Read more]
The freshly released MySQL 8.0 includes a data dictionary, which makes MySQL much more reliable. Thanks to this features, we don't have any '.frm' files, and querying the information_schema is 30x to 100x faster than previous versions.
One drawback of the implementation is that the data dictionary tables are hidden by design.
While the reason is fully understandable (they don't want to commit on an interface that may change in the future) many curious users are disappointed, because openness is the basis of good understanding and feedback.
The problem to access the dictionary tables can be split in three parts:
- Finding the list of tables; …
MySQL is a growing presence at Oracle Open World. While most of the headlines belong to the main products, where Oracle services are aiming at world domination, MySQL shared the spotlight, as it was announced to be part of Oracle database cloud. It seems a logical move for Oracle: after all the effort to make MySQL 5.7 the biggest release ever, it stands to reason that it is offered as a competitive feature in its own database as a service.
With this offer, Oracle is applying enterprise pricing and methodologies to a target of emerging companies. MySQL in the Oracle cloud differs from the competition by a few key points:
- It's only MySQL 5.7. While this is the most advanced MySQL server …
There was a bold announcement during the MySQL Keynote at Oracle Open World. A new product that will mix up with the existing GA server, called MySQL InnoDB Cluster. This is an evolution of MySQL group replication, which has been in the labs for long time, and the MySQL shell, which was introduced as a side feature last April. The boldness I mentioned before is on account of wanting to add to a GA server something that was defined as release candidate despite never having been out of the labs. The product is interesting as it promises to be a quick and painless cluster deployment, with built-in high availability and scalability.
Now that MySQL 8.0 has been revealed, it's time to take a deep look at replication features in the latest releases, and review its overall design.
Server UUID vs Server-ID
At the beginning of replication, there was the
server_id variable that identified uniquely a node
in a replication system. The variable is still here, but in MySQL
5.6 it was joined by another value, which is created during the
server initialisation, regardless of its involvement in a
replication system. The
server_uuid is a string of
hexadecimal characters that is the basis for global transaction
select @@server_id, @@server_uuid;
| @@server_id | @@server_uuid |
Databases power today’s e-commerce. Whether it’s listing items on your site, contacting your distributor for inventory, tracking shipments, payments, or customer data, your database must be up, running, tuned and available for your business to be successful.
There is no time that this is more important than high-volume traffic days. There are specific events that occur throughout the year (such as Black Friday, Cyber Monday, or Singles Day) that you know are going to put extra strain on your database environment. But these are the specific times that your database can’t go down – these are the days that can make or break your year!
So what can you do to guarantee that your database environment is up to the …[Read more]
MySQL 8.0.0 was released today. It has been some time in the making, shrouded in a veil of secrecy for over one year. We knew, from listening to the gossip and looking at the few available previews, some of what was going to bring. So, for the observant users, its main features may not come as a surprise. For the rest of you, here's a quick roundup:
- No MyISAM tables anymore! The grant tables are now InnoDB, meaning that grant operations are now atomic.
- A real data dictionary. This change is less visible than the previous one. The data dictionary tables are hidden and only a subset of the data is available through information_schema views. The reason for the hidden tables is to allow a stable interface through several versions. I am …
The schedule to Percona Live Europe 2016 is being finalized. It should be published soon, and it will include 3 hour and 6 hour tutorials, regular 50-minute talks, and shorter 25-minutes talks. It will not include, however, the lightning talks, a session comprising several 5-minute talks, and they are missing from the initial schedule for two reasons:
- We want to offer a chance to all attendees to propose a lightning talk for some time. We would like to have more quality material to choose from.
- They will not be in the conference venue. Instead, they will be hosted at Booking, during the community dinner.
Unlike in previous editions, though, the lightning talks will …[Read more]
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