I’m scheduled to deliver several free MySQL webinars via Percona and ODTUG in the upcoming weeks. I hope you can join me:
Further Reading:
[Read more]Are you involved with an open-source project that’s interesting to MySQL users, such as Nginx, PHPMyAdmin, Drupal, Jenkins, PHP, and so on? Percona just published the application form for dot-org groups to have a free expo hall booth in the Percona Live MySQL Conference in April. Please submit your applications now, and tell your friends about this, because a) the schedule for applying is very short, and b) space is limited.
For those of you who don’t know what this is, it’s another of the O’Reilly traditions we’re trying to continue. (We are trying very hard to make this event as close to a clone of O’Reilly’s as we can.) It’s a free table in the expo hall where people who participate in a non-commercial open source project can exhibit. I organized a Maatkit booth a few times in the past, and was always …
[Read more]Schooner has a blog post showing that one node of their product beats 9 nodes of Clustrix’s in throughput. But this reduces everything to a single number, and that’s not everything that matters. If you’ve looked at Vadim’s white paper about Clustrix’s (paid-for) performance evaluation with Percona, you see there is a lot of detail about how consistent the throughput and response time are.
I’d love to see that level of details in any product comparison. A single number often isn’t enough to judge how good the performance is — fast is not the only thing that matters.
I have absolutely no doubts that a single node of Schooner’s product can run like a deer. It isn’t doing any cross-node …
[Read more]http://collaborate12.ioug.org Double Down at COLLABORATE 12- The IOUG Forum with Two Ways to Save- and a Chance to Win! The user-driven Oracle event of the year is fast-approaching, and IOUG wants you to make youreducational experience a sure bet. Between … Continue reading →
The first Central Virginia MySQL Meetup was a nice little howdy-do, and as a test flight, I think it showed that the bird can get off the ground quite nicely. So, with the generous help of our meeting host Meddius, we’re going to do it regularly on the 3rd Wednesday of every month. The next event is already scheduled — I will be talking about high availability options for MySQL.
I’m interested in having outside speakers. Anyone who’d like to come and present something MySQL-relevant, please feel free to email me, or contact me via the Meetup page with the “suggest a Meetup” feature. If you’re traveling from outside the area, the airport is CHO, and it’s about 30 minutes away. Amtrak is also …
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Somebody asked for a simple comparison between a PL/SQL
pass-by-value function and pass-by-reference procedure, where the
procedure uses only an OUT mode parameter to return
the result. This provides examples of both, but please note that
a pass-by-value function can be used in SQL or PL/SQL context
while a pass-by-reference procedure can only be used in another
anonymous of named block PL/SQL program.
The function and procedure let you calculate the value of a number raised to a power of an exponent. The third parameter lets you convert the exponent value to an inverse value, like 2 to 1/2.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
CREATE OR REPLACE FUNCTION find_root_function ( pv_number BINARY_DOUBLE , pv_power BINARY_DOUBLE , pv_inverse BINARY_INTEGER DEFAULT 0 ) RETURN BINARY_DOUBLE IS -- Declare local variable for return value. … |
I recently wrote a post about inner and outer joins, and a couple of people
asked what the difference is between USING and
ON.
In a nutshell, you use ON for most things, but
USING is a handy shorthand for the situation where
the column names are the same.
Consider this example dataset:
mysql> select * from pets; +---------+---------+--------+-----------+ | pets_id | animal | name | owners_id | +---------+---------+--------+-----------+ | 1 | fox | Rusty | 2 | | 2 | cat | Fluffy | 2 | | 3 | cat | Smudge | 3 | | 4 | cat | Toffee | 3 | | 5 | dog | Pig | 3 | | 6 | hamster | Henry | 1 | | 7 | dog | Honey | 1 | …[Read more]
I recently wrote a post about inner and outer joins, and a couple of people
asked what the difference is between USING and
ON.
In a nutshell, you use ON for most things, but
USING is a handy shorthand for the situation where
the column names are the same.
Consider this example dataset:
mysql> select * from pets; +---------+---------+--------+-----------+ | pets_id | animal | name | owners_id | +---------+---------+--------+-----------+ | 1 | fox | Rusty | 2 | | 2 | cat | Fluffy | 2 | | 3 | cat | Smudge | 3 | | 4 | cat | Toffee | 3 | | 5 | dog | Pig | 3 | | 6 | hamster | Henry | 1 | | 7 | dog | Honey | 1 | …[Read more]
Join me Wednesday for a free webinar on using the new Percona Toolkit v2.0.3 to verify replication integrity. If you’re not familiar with this topic, it’s one of those must-do things that no one officially tells you is necessary with MySQL. The new tools in Percona Toolkit 2.0.3 make it much easier and less complicated — and safer — than before. Well worth an hour of your time.
Further Reading:
[Read more]You can pre-order the new edition of High Performance MySQL now on Amazon or via O’Reilly’s website.
Eric Bergen called the second edition “the best MySQL book on the planet“. What will the third edition be called? The best in the solar system? This reminds me of a joke, supposed to be a true story: three pizza restaurants next to each other had signs saying “best pizza in town,” “best pizza in the world,” and “best pizza on this block.”
Further Reading: