Log Buffer #174: A Carnival of the Vanities for DBAs
Jan 8, 2010 / By David Edwards
Happy New Year to all our readers! Welcome to 2010 and the 174th edition of Log Buffer, the weekly review of database blogs.
The MySQL ‘sphere since the holidays has been thick with posts on the matter of Oracle’s purchase of Sun, and thereby of MySQL. And in particular, there’s been a lot of talk about MySQL founder Monty Widenius’s response. I call all of this the . . .
On the 28th of December, Monty framed the issue thus: Help keep the Internet free.
On Poo-tee-weet, Lukas Kahwe Smith is heard to say, Come on Monty . . . “What on earth is Monty . . . thinking? How can you spin around 180 and expect to come of believable? How can suddenly the GPL be the wrong choice? How can suddenly OSS depend on proprietary sales?”
On the WireLust blog, Terrence Curran writes, Monty Widenius is trying to regain control of MySQL and why this is bad for OSS.
On someGreatTechName, Piotr Jasiulewicz shows how to get data without reading it – the power of covering indexes in MySQL.
Peter Zaitsev of the MySQL Performance Blog lays out the principles of upgrading MySQL, “ . . . a very interesting task as you can approach it with so much different ‘depth’. For some this is 15 minutes job for others it is many month projects. Why is that?”
Aaron also has a quick poll: what is your favorite Management Studio tip or trick?
Simon Sabin wonders aloud, Should PASS hold the conference on the East coast?
Simon also has his latest TSQL challenge – remove duplicates from a string.
Let’s begin with nothing. Tanel Poder wishes to remind us that NULL is not zero!, with, “an example [of] how misunderstanding NULLs may cause your application to return different results than what was intended.”
Martin Widlake has been busy decoding high_value and low_value for us. He writes, “The table DBA_TAB_COLUMNS holds the LOW_VALUE and HIGH_VALUE for columns. This information is potentially very useful to us . . . What is not so helpful is that Oracle stores, and displays, the information in an internal raw format. Which is utterly unhelpful to us of course.”
Jonathan Lewis clarifies copy stats. “ . . . someone was having trouble,” he writes, “copying stats from one index to another using the import_index_stats and export_index_stats procedures from package dbms_stats modifying the contents of their ‘stat table’ between the export and import. . . . Part of the problem with this approach is that you’re not really supposed to do what they were trying to do . . . ”
Guy Harrison, meanwhile, elucidates 11gR2′s IGNORE_ROW_ON_DUPKEY_INDEX hint, “ . . . [one] of the strangest new features in 11GR2 . . . Why is this so strange? Mainly because unlike almost all other hints, this hint has a semantic effect: it changes the actual behavior – not just the optimization – of the SQL.”
Walking in the footsteps on Vasco da Gama, Luis Moreno Campos proclaims himself the first Portuguese Oracle nerd to unpack an Oracle-Sun Exadata v2. Congratulations, Luis! I think.
And we close this edition of Log Buffer with Jonathan Lewis, who on first principles, “ . . . just had to start the new year with a little humour,” courtesy of Og, Sumerian DBA.
That’s all for now. If I’ve missed you favourite DB blog from the last week, please leave a comment. See you again for LB #175.