I will be demonstrating the features of Flexviews as well as
talking about how you can improve performance by:
By “Good SQL Querying”, I am not referring to “how to make your queries more perfomant.” I am about to go on a mini-rant about how to make readable and self-documenting SQL queries.
One practice that will get me instantly going on a rant is using a comma join. There is NO reason to do the following:
-- uses the sakila sample database SELECT first_name, last_name, address FROM customer,address;
What kind of join did the original author intend? A CROSS JOIN? Or did they really want an INNER JOIN and forget the WHERE clause?
The answer: you do not know for sure; you can only guess. Had the query been
SELECT first_name,last_name,address FROM customer INNER JOIN address;
you would know that the author intended an INNER JOIN; had the query been
SELECT first_name,last_name,address FROM customer CROSS JOIN address;
you would know that the author intended a CROSS JOIN. I …
[Read more]Most days Matt Asay's blind love for OSS makes me laugh. Today is no different. In giving advice to Ballmer, Matt has the following particularly hilarious quotes: "Ballmer lacks the imagination to conceive of a world where Microsoft could open source code and still make a lot of money (He's apparently not heard of "Google"):" Umm, just so we're clear, we're taking about the same Google that makes billions on its proprietary search & AdSense algorithms encoded in proprietary software? Just because Google decides to open source some ancillary pieces of their infrastructure and supports OSS projects that they consume... READ MORE
Week 6 (30th June – 7th July 2008 )
Key Accomplishments Last Week
1. Implemented a feature to rearranger.c to allow it to accept multiple input files (as requested by Brian). There are a few problems with this feature, however, and I plan on rectifying them soon.
2. Learnt some basics of Lua.
3. Learnt a bit about the ddd.
4. Started learning about the internals of mysql and bought a book, “Expert MySQL” by Charles A. Bell. I already have a fair idea about the working of mysqlslap. Once I get a good grasp of the ddd debugger I should be able to understand mysqlslap more thoroughly.
Key Tasks that stalled last Week
None
Key Concerns
The upcoming midterm evaluation gives me a sense of urgency in my work. On looking back, I feel I have given my best but it could definitely have been better. Hope …
[Read more]Week 6 (30th June – 7th July 2008 )
Key Accomplishments Last Week
1. Implemented a feature to rearranger.c to allow it to accept multiple input files (as requested by Brian). There are a few problems with this feature, however, and I plan on rectifying them soon.
2. Learnt some basics of Lua.
3. Learnt a bit about the ddd.
4. Started learning about the internals of mysql and bought a book, “Expert MySQL” by Charles A. Bell. I already have a fair idea about the working of mysqlslap. Once I get a good grasp of the ddd debugger I should be able to understand mysqlslap more thoroughly.
Key Tasks that stalled last Week
None
Key Concerns
The upcoming midterm evaluation gives me a sense of urgency in my work. On looking back, I feel I have given my best but it could definitely have been better. Hope …
[Read more]In our latest database journal piece, we cover some useful Oracle-supplied pl/sql stored procedures to help you instrument and debug your code, dump metadata descriptions of your database objects (a la MySQL dump –no-rows) and much more.
Take a look at DBA Insider - Useful PL/SQL Packages.
?WL4271 Encrypted Online Backup: Preview 3? branch in Launchpad
Now with Windows support. Many thanks to Chuck Bell for helping get the code going on Windows.
We can however, all sit around dumbfounded as to how Windows has so little of a POSIX like layer and yet doesn’t define ENOTSUP.
As a refresher, this tree implements:
(world peace not included)
UPDATE: If you’re wondering why the branch isn’t there, it’s still pushing to launchpad. Yes, that’s over 7 hours to push a branch. ick. Can’t be too …
[Read more]
available now: Flexviews for MySQL 1.0.2-alpha
bug fixes:
ensure_validity() was failing when an incremental refresh mview
did not contain an AVG()
the delta application phase of refresh was not cleaning up the
delta log
removed serialization overhead, improving dml performance. needs
further improvement.
Get it at:
http://sourceforge.net/projects/flexviews/
One of our customers was setting up box for MySQL LVM backups. The box had 2 RAID volumes (internal drives and enclosure) with database being stored on enclosure drives and internal drives used pretty much for OS and logs (database grew too large and so was moved to enclosure completely).
As database was large and active I thought it would make sense to have LVM undo space located on the internal drives so LVM and backup has less backup on the running system.
As the system was configured creating snapshot volume with 100G of undo space failed complaining there is not enough space available on the volume….
The problem was internal and external volumes were configured as different “volume groups”. Volume groups in LVM live completely isolated life and you can’t use space from one volume group for snapshot for another.
What should have done instead is creating single volume group and having RAID volumes as …
[Read more]Today Sun announced release of X4540 Open Storage server (a.k.a Thor). We were fortunate to get early access to Thor to certify Amanda Enterprise and Zmanda Recovery Manager (ZRM) for MySQL. Both solutions are optimized for backing up to disk, are already certified with Solaris 10, and leverage capabilities of ZFS. So it made perfect sense to certify them on Thor, effectively creating a high-performance and yet relatively inexpensive backup appliance.
The unit we were using is powered by 8 CPUs operating at 2300 MHz and provides 48 SATA drives with total capacity close to 50TB in 4U enclosure. That is good packing; a typical EMC unit with so much capacity will take the whole rack.
…[Read more]