Log Buffer #162: A Carnival of the Vanities for DBAs
Sep 18, 2009 / By David Edwards
Welcome to the 162nd edition of Log Buffer, the weekly review of database blogs.
The big news this week came was Oracle’s unveiling the OLTP Oracle Database Machine & Exadata v2, as reported by Alex Gorbachev.
Kevin Closson covered it, of course: Oracle Drops Exadata In Favor of Sun FlashFire Based OLTP Database Machine?, and he and his readers kick it around in a diverting way.
The dbaStreet blog offered their very thorough HOWTO, 11gR2 rac installation on 64 bit Linux step by step.
If that’s not enough “R” for you, there’s another item in the “Q” — Cary himself on the importance of diagnosing before resolving.
The Rusano blog shared their thoughts on SQL Server’s boolean operator short-circuit. “Many developers that come from an imperative language background like C are relying on boolean short-circuit to occur when SQL queries are executed. . . . I’ve stayed close enough to Microsoft CSS front lines for 6 months to see actual cases pouring in from developers bitten by the short-circuit assumption.”
The MySQL Performance Blog announced a new statistical bauble: statistics of InnoDB tables and indexes available in xtrabackup.
Shlomi Noach shared some of his thoughts on ranking without self join in SQL, which he introduces thus: “The common way of solving the classic SQL problem of ranking, involves a self join. I wish to present a different solution, which only iterates the table once, and provides the same output.”
Roland Bouman responded with another ranking trick: “Shlomi’s trick reminds me somewhat of the trick I came across little over a year ago to caclulate percentiles. At that time, several people pointed out to me too that using user-defined variables in this way can be unreliable.”
Those MySQL@Facebook people say, “Most of the tests in the MySQL regression test suite are hardwired to use MyISAM or InnoDB. This has made it difficult for new storage engines to run these tests. PBXT has spent too much time modifying these tests and maintaining a huge patch for that modification. Guess what? Now we all need the storage-engine independent test suite.” (Google cache.)
That’s all for now. Please share your favourite DB blogs from this week in the comments. See you in a week!