Log Buffer #163: A Carnival of the Vanities for DBAs
Sep 25, 2009 / By David Edwards
Welcome, readers, to the 163rd edition of Log Buffer, the weekly review of database blogs, your sieve
First, the ghastly news—Tom Kyte said “I’m not a DBA anymore.” Say it ain’t so, Tom! “After nine years and nine months of running the database that hosts asktom, I’ve retired . . . not from answering questions, but rather from being the DBA and semi-SA for the machine that was asktom.oracle.com.” Okay, so he said it ain’t so.
Meanwhile, Tom’s Oak Table colleague, Jonathan Lewis, played no head games on us, but he has been at the hash partitions. He writes, “I made a throwaway comment in a recent posting about using powers of two for the number of partitions when using hash partitioning. . . . Here’s a simple demonstration of hash partitioning in action demonstrating why Oracle adopted this ‘power of 2′ rule.”
Hemant’s Oracle DBA Blog featured an item on SQLs in functions: each execution is independent. “Functions (Stored PLSQL code that return a single value at each call) are good for calculations, validation against business rules etc. But when you use them for lookups, you must watch out for underlying data being changed!”
A new blog appeared in the firmament, namely James Morle’s. For his very first post, he avers, Forget I/O Bound, You’re Latency Bound, Bub. “Latency . . . is a silent killer. Silent, in that it often goes undetected, and the effects of it can kill performance (and still remain undetected). I’m not going to go into all the analogies about latency here, but let’s try and put a simple definition out for it . . . ”
Quiz time! On So Many Oracle Manuals, So Little Time, Iggy Fernandez asked, Which Query is Better? You many turn over your papers. “In general, there are lots of ways of expressing a particular query requirement in SQL with implications for query performance. For example, which departments have employees with salaries greater than a certain cutoff? Here are two ways to express this query requirement in SQL.”
And now for some Larry Ellison.
Wait, what’s he doing in the MySQL section?!? Oh, right. That. Maybe that makes you a little uncomfortable? Well, get used to it. Ellison: Oracle won’t spin off MySQL, according to Lance Whitney.
If playing with Larry is not your thing, maybe you’d prefer to be having fun with Tokyo Tyrant. Patrick Galbraith writes, “Tokyo Tyrant is a database server, written by Mikio Hirabayashi, for Tokyo Cabinet.” He installs it, and puts it through its paces, and later tries out the Tyrant’s memcached functions for MySQL.
That does sound like fun. No? How about fun with mysqlslap benchmarking on Everything MySQL? It begins, “Mysqlslap is a good benchmarking tool but can be much more versatile in my opinion. So, recently, I was benchmarking a problem that was, not hard to solve, but somewhat tricky to benchmark. Using mysqlslap was the fastest way to get the answers I wanted with the least amount of BS, or so I thought!”
Over on SQLBlog, Linchi Shea exposed the Transact-SQL prime directive: “‘There can be no interference with the flow of set-based data in Transact-SQL.’ – the Prime Directive for the design of Transact-SQL. . . . No, this is not from Microsoft, and of course, I made it up.” Linchi defends his invention, but he also wants to hear yours.
Aaron Alton, the HOBT, says lousy HA is not necessarily better than no HA. Ha! “In fact, it can be worse,” writes Aaron. “And no, I’m not just being a retentive purist. Hear me out.” Will do—it’s a point well made.
SQLCAT’s Technical Notes shared some thoughts on availability in Resolving PAGELATCH Contention on Highly Concurrent INSERT Workloads, focusing on diagnosing and circumventing the problem with table partitioning.
Paul Nielsen had his head in the cloud—he’s been looking at SQL Azure – hands on. “Last week,” Paul writes, “I took the SQL Azure CTP for a test-drive. It took me about 2 hours to fix all the incompatibilities with my code, and move my test database to SQL Azure. And Wow it’s very, very fast. Did I mention that it’s fast? I really like SQL Azure.”
The cloud, and the crowd—popular words these days, but not everyone likes them. Josh Berkus, for example, insists: “Never Say Crowdsourcing”. I admit this is a little—or maybe more than a little—off-topic, but this is a provocative article worth reading. Josh begins, “One of the words I’m hearing more frequently used by people who should know better lately is ‘crowdsourcing’. This word is, to put it mildly, evil. Like racist slurs or terms for degrading sexual acts, it’s not a word you should be using.” So, tell us what your really think, Josh.
That’s all for now. Please let’s hear your favourite DB blogs in the comments. See you in a week’s time.