The MariaDB CONNECT storage engine now offers access to JSON file and allows you to see a external JSON file as a MariaDB table. JSON (JavaScript Object Notation) is a lightweight data-interchange format widely used on the Internet. JSON like XML represents data hierarchically. The mapping from hierarchical data to tabular data needs to be specified.
[...]
MySQL is fairly relaxed about prefixing column names with a table name or alias in a query involving multiple tables. As long as the column name you use only exists in one of the tables in your query, MySQL does not require you to prefix it, regardless of SQL mode.
My policy has always been to prefix all column names with the table name/alias in a multiple table query. This is not simply a syle choice. If I reference a column name without prefixing it the query may work today, but it is not future-proof. If the schema changes in the future and I add a column with the same name to one of the other tables involved in that query, then the query will fail with ERROR 1052:
ERROR 1052 (23000): Column 'used_to_be_unique' in field
list is ambiguous
Therefore I recommend always prefixing all column names in a multi table query to protect your queries against future additive schema changes.
Here's some code …
[Read more]In the MySQL team, we have always had a requirement to support upgrades from one major version. For example:
Downgrades are also supported for one major version. For example, if a user upgrades to 5.6 but discovers that it is not working as expected, they have the safety knowing that there is a way to step back to MySQL 5.5. This may come with some limits; for example when new features (such as new row formats or page checksums) are enabled, this may no longer be possible.
Today I wanted to discuss a current non-requirement. We do not support skipping major versions, such as upgrading from MySQL 5.1 to 5.6. Justin however makes the …
[Read more]The Severalnines team is pleased to announce the release of ClusterControl 1.2.9. This release contains key new features along with performance improvements and bug fixes. We have outlined some of the key new features below.
Join us for our Release Webinar on March 24th, which includes a live demo of the new ClusterControl 1.2.9.
Highlights of ClusterControl 1.2.9 include:
I am leaving Oracle. My last day will be tomorrow. Since Oracle blogs are
for Oracle employees only I would not be able to post here. I
will write new posts to my personal just created blog http://troubleshootingfreak.blogspot.com/
This blog will stay, so you should be able to access older entries. Therefore I would not migrate them. Just don't expect somebody will manage comments. If you have questions about old entries in this blog use this page.
Last years I worked on JSON UDF project. I will stop working on it after I leave to avoid conflict of interest with Oracle, but project will live. I don't know if it will be passive or Oracle will find new developer for it, but versions 0.3.3 and …
[Read more]
Tomorrow will be my last day at Oracle. Next day I would not have
access to my working blog at https://blogs.oracle.com/svetasmirnova/ But
content will stay.
However Oracle blogs require manual managing of comments and I
simply don't expect my colleagues will have time to do it in
timely manner. Therefore if you have questions about my old blog
posts just write them here together with the URL of the post.
We are getting closer to the next major version of MySQL, and yesterday we announced another development milestone release of what will become MySQL Server 5.7. In addition to the announcement blog post itself, more in-depth posts on specific changes and improvements in the 5.7.6 milestone release will appear on the MySQL Server Team blog over the next […]
Introduction
The MySQL Optimizer sometimes needs a temporary data-store during
query processing, for storing intermediate results. Before
MySQL 5.7, this need was serviced exclusively using a combination
of the HEAP/MEMORY storage engine (for smaller
tables) and the MyISAM storage engine (for larger
tables). You can find more information on when disk based
temporary tables (MyISAM or InnoDB) are used instead of MEMORY
tables here.
The …
The MySQL Performance Schema exposes so much data that it’s not trivial to learn, configure, and use. With recently released Percona Agent 1.0.11 you can get query metrics – like min, max, and average query execution time – with a few clicks:
Click “Apply” and about two minutes later you’ll have query metrics from Performance Schema, collected and sent every minute.
Percona Cloud Tools (PCT) and Percona Agent handle all the details. You’ll need MySQL (or Percona Server) 5.6 and Percona Agent 1.0.11 or newer. One caveat at the moment: it …
[Read more]NetProspex is a B2B platform that enhances lead generation by separating the information that matters and enabling marketers to better segment and target their audience. Managing the massive amount of incoming data is cumbersome for one DBA.
In the past, NetProspex used tools like Nagios and MySQL Enterprise Monitor (MEM), but both fell short of the company’s monitoring needs. Hiring another DBA was both difficult and expensive, so Josh Prunier, DBA at NetProspex, began evaluating alternative solutions. VividCortex’s MySQL-specific query intelligence was better suited.
VividCortex made an immediate positive impact on Josh’s workload and overall operations by improving insight into query and server behavior and reducing overhead costs. The ability to compare and analyze queries allows Josh to proactively examine queries that are not written efficiently and take actions such as tweaking an index or the query syntax. The deep …
[Read more]
