In the last blog I spoke of CPU counters. Now, I'll talk of Memory counters.

MEMORY Counters (CIM_PhysicalMemory class, Win32_PerfFormattedData_PerfOS_Memory class, Memory Performance Information ...): Note: I introduced the notion of samples and how to fetch them using NextValue() so I will occasionally omit $var.NextValue() going forward.

Let me note here that if you thought previously described performance classes were complicated, you are now entering the realm of black magic ;-) There is a good …

So this year the Percona Live conference has a new name — it is the “Data Performance Conference” (presumably for a much broader appeal and the fact that Percona is now in the MongoDB world as well). And the next new thing to note? You have to go through a process of “community voting”, i.e. the speaker has to promote their talks before via their own channels to see how many votes they can get (we tried this before at the MySQL & Friends Devroom at FOSDEM; in this case, please remember you also need to create a new account and actually vote while logged in).

I hope you vote for Sergei, Monty and my proposals!

1. Using and Managing MariaDB – a tutorial, which has …

Performance Schema has been with us for a while now. Over the years, it has gone a long way from being a curiosity disabled by default to becoming a sophisticated diagnostic tool you may want to enable permanently in your production database.
MySQL 5.7 introduced some exciting Performance Schema features and the first one I'm going to look at is the instrumentation for server memory usage. Have I Got Data For You MySQL 5.7.9 (GA) supports the following memory summary tables (per documentation) that let you look at server memory usage from different angles:

• "memory_summary_by_account_by_event_name" summarizes events for a given account.
• "memory_summary_by_host_by_event_name" summarizes events for a given host.
• "memory_summary_by_thread_by_event_name" summarizes events for a given thread and event name.
…

The show goes on. This Log Buffer Edition picks some blogs which are discussing new and old features of Oracle, SQL Server and MySQL.

Oracle:

• Directory Usage Parameters (ldap.ora) list the host names and port number of the primary and alternate LDAP directory servers.
• Data Visualization Cloud Service (DVCS) is a new Oracle Cloud Service. It is a subset offering of the currently supported Business Intelligence Cloud Service (BICS).
• ORA-24247: network access denied by access control list (ACL).
• Latches are low level …

This article is continuing the MySQL 5.7 Performance story, started from 1.6M QPS on MySQL 5.7 details post , then 1M QPS on mixed OLTP_RO with MySQL 5.7 article, and detailed story about why the Point-Selects performance is so critical (and why the 1M result published by MariaDB is not fair)..

The current story will be about Connect/sec (connect/disconnect) performance improvement in MySQL 5.7 - such kind of metric is very critical for any application which cannot use persistent connections all the …

Thanks to everyone who joined us for our recent live webinar on performing live database upgrades for MySQL Replication & Galera, led by Krzysztof Książek. The replay and slides to the webinar are now available to watch and read online via the links below.

During this live webinar, Krzysztof covered one of the most basic, but essential tasks of the DBA: minor and major database upgrades in production environments.

Watch the replay

Become a MySQL DBA: performing live database upgrades - webinar replay from Severalnines AB  

Read the slides

…

For a long time we’ve been dissatisfied with the fact that we had two separate tools to do the same thing: Top Processes and Top Queries rank processes and queries respectively by a metric of your choice. For example you may rank queries by frequency, or rank databases by total execution time. There’s a lot of shared functionality and at the same time there’s so much more we could do with the metrics we’re capturing from your systems.

Today we are releasing a new tool called Profiler to replace Top Queries and Top Processes, so now we have one tool to do the job of two. Simplifying is always a good thing.

If you are wondering what the Profiler can rank, you’ll be glad to see that not only we still rank Users, Databases, Hosts, Queries, Verbs, Tags and Processes, but we also added Tables, Network Sockets, MySQL Commands and MySQL Processlist Queries. And many more are coming soon of …

Support for storing and querying JSON within SQL is progressing for the ANSI/ISO SQL Standard, and for MySQL 5.7. I'll look at what's new, and do some comparisons.

The big picture

The standard document says

The SQL/JSON path language is a query language used by certain SQL operators (JSON_VALUE, JSON_QUERY, JSON_TABLE, and JSON_EXISTS, collectively known as the SQL/JSON query operators) to query JSON text.The SQL/JSON path language is not, strictly speaking, SQL, though it is embedded in these operators within SQL. Lexically and syntactically, the SQL/JSON path language adopts many features of ECMAScript, though it is neither a subset nor a superset of ECMAScript.The semantics of the SQL/JSON path language are primarily SQL semantics.

Here is a chart that shows the JSON-related data types and functions in the standard, and whether a particular DBMS has something with the same name and a similar functionality. …

In my last post playing with MySQL fabric here and here I used MySQL fabric version 1.4.1 and MySQL 5.6, i must say lot's of things have happened over the last 20 months! MySQL have released several new versions of MySQL Fabric and also a new version of the server with MySQL 5.7.

Current GA version of MySQL Fabric is 1.5.6 and there is also a MySQL Fabric 1.6.2 beta, both versions can be downloaded from here.
As I said earlier, lots of new things have happened, looks like focus has been on making it easier to work with MySQL Fabric but also making output from fabric commands much easier to understand. With latest version 1.6.2 (not …

I got some more questions on the new JSON data type and functions during our TechTours. And I like to summarize the answers in this blogpost.
Memory consumption The binary format of the JSON data type should consume more memory. But how much? I did a little test by comparing a freshly loaded 25,000 row dataset stored as JSON and stored as TEXT. Seven top level attributes per JSON document. Average JSON_DEPTH is 5.9 . Let's see:

mysql> DESC data_as_text;
+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id    | int(11) | NO   | PRI | NULL    |       |
| doc   | text    | YES  |     | NULL    |       |
+-------+---------+------+-----+---------+-------+
2 rows in set (0.00 sec)

mysql> SELECT COUNT(*),AVG(JSON_LENGTH(doc)) FROM data_as_text;
+----------+-----------------------+ …