Posts by Sheeri Cabral
Recently I had an interesting issue crop up. Due to an unfortunate migration incident in which involved master/master replication and not checking to see if replication was caught up, we ended up with an infinite replication loop of a number of SQL statements. awk helped immensely in the aftermath cleanup. The basics of the replication infinite loop were…
This is a post about SYSDATE() and NOW() and CURRENT_TIMESTAMP() functions in MySQL. Firstly, note is that of these three, only CURRENT_TIMESTAMP() is part of the SQL Standard. NOW() happens to be an alias for CURRENT_TIMESTAMP() in MySQL. Secondly, note that replication does not work well with non-deterministic functions. You can start to see the problem here….but there’s more….
The unsung heroes of InnoDB are the logfiles. They are what makes InnoDB automatic crash recovery possible. When data is changed, affected data pages are changed in the innodb_buffer_pool. Then, the change is written to the redo log, which in MySQL is the InnoDB logfile (ib_logfile0 and ib_logfile1). The pages are marked as “dirty”, and eventually get flushed and written to disk. On crash recovery, MySQL can read the redo log (InnoDB log files) and apply any changes that were not written to disk. That is the basic functionality of the InnoDB log files. Given this, let’s look at some of the different parameters and their ramifications.
As I putter around the MySQL INFORMATION_SCHEMA, I am finding lots of undocumented behavior for fields that should be straightforward. when I was looking at the VIEW_DEFINITION today, I noticed an odd thing. Even though I had permissions to see the view definition, the INFORMATION_SCHEMA.VIEWS table sometimes came up blank for the VIEW_DEFINITION. I had to figure out why, and now that I know, I’m not sure if it’s a bug or a feature…..can you figure it out?
A while ago, MySQL developed a Community Contribution Agreement for community contributions to the MySQL source code. While browsing the MySQL Forge Wiki I came across a page about how the Community Contribution Agreement has changed
Gavin Newsome, mayor of San Francisco, and Ed Begley, Jr. talk about being green, and commend Oracle and Oracle OpenWorld for being green.
To start off the conference, the first keynote at Oracle OpenWorld took a break from technology and veered into the world of politics. The official conference description says: Washington’s best-loved political couple Mary Matalin and James Carville entertain the crowd with a bitingly humorous look at the world of politics. Indeed, there was humor, and politics. For a light-hearted yet factual look at US politics
Next week, Dan Norris and I will collaborate on a presentation at Oracle Openworld 2008. Our presentation, entitled So, You Want to be an Oracle ACE?, will be on Monday, 9/22, from 11:30 am – 12:30 pm in Moscone South, room 310 — that’s the very first conference slot. We’ve already put together our presentation, with input from many Oracle ACEs and Oracle ACE directors, complete with some great video clips. I’m excited and honored to be presenting with Dan. The official description of our presentation is…
This article is about the WHERE extension to SHOW. I specifically use SHOW STATUS as an example, but WHERE is an extension to many SHOW statements.
Last week I speculated about the impact of Monty leaving Sun. In the end, if he does stay, it’s wonderful for Sun. If he leaves, he will no doubt go on to continue to be wonderful for the database community at large, much like Jim Starkey. But until Monty Says, nothing is official.