Log Buffer #172: A Carnival of the Vanities for DBAs
Dec 11, 2009 / By David Edwards
On the MySQL Performance Blog, Peter Zaitsev and his readers discuss the question, how many partitions can you have? In Peter’s opinion, “ . . . be careful with number of partitions you use. Creating unused partitions for future use may cost you.”
Also, Peter’s colleague Aleksandr Kuzminsky announces the release of xtrabackup-1.0, an “open source online (non-blockable) backup solution for InnoDB and XtraDB engines.”
Nick will also be tackling next’s week’s Log Buffer.
Harrison Fisk’s MySQL Thoughts this week included this item about an Ext4 with MySQL binary logs oddity. “ . . . we were able to pin it down to ext4 and how it delays data writes for a very long time (30 minutes).”
As long as we’re in
/var, here’s Eric Bergen, attempting to unwind the tangled web of pid file creation, which he started doing having discovered a pid file creation race condition in mysqld_safe.
Dave Page, PostgreSQL hacker and core team member, brings word that PostgreSQL at FOSDEM 2010 – the call for talks has been issued. Dave also has a post clarifying the PostgreSQL release support policy.
Linchi Shea exposes the performance impact of UNION ALL views, ANSI_PADDING, and bad query plans. Writes Linchi, “Whether or not you specify it explicitly, ANSI_PADDING setting is there when you create a table, and can have an impact on the performance of some queries. If you are not careful, it can even hurt performance big time!” Examples and script follow.
In a post is called, For want of a nail, Michael Zilberstein writes, “I’ll describe here how small bug can ‘kill’ [a] strong server. The story begins when for some unknown reason [the] ‘rows’ column in [the] sys.partitions DMV begins to show 4.6 billion rows . . . ”
Adam also provides a roundup of T-SQL Tuesday #001 (Date/Time Tricks).
Let’s start the Oracle news with some reviews of the UKOUG Conference, which closed last weekend. Here are adhd ocd dba’s notes from UKOUG, and Marco Gralike’s UKOUG 2009 wrap-up: “The wifi was a minor bummer, but the rest was up on high standard as always. Good quality presentations as should be expected.”
Martin Widlake introduces, “ . . . a tuning method with partition exclusion where you infer a relationship between the value you want to limit a query on and the partition key. It takes a while to explain the theory so I am going to give it a name, in the vain hope it catches on . . . I’m going to call it Correlated Partition Exclusion.”
The Oracle Performance and Backup Blog offers the first part of a series on Oracle RAC One Node, which is, “about a installation and configuration of Oracle RAC 11gR2 in One Node configuration on VMWare.”
To close things, here is Drupal guy Dries Buytaert on NoSQL and SQL. Dries writes, “Have a look at this video of Brian Aker’s great 10 minute lightning talk about NoSQL. NoSQL is a database movement which promotes non-relational data stores that do not need a fixed schema. . . . NoSQL is an ‘and’ and not a ‘versus’. Plus, I expect the gap to close as there are a couple of interesting projects under way that bring some of the NoSQL advantages to the SQL world. One of them is Brian Aker’s own Drizzle project . . . [Have] a look Brian’s NoSQL presentation. It’s funny!”
That is all. As always, I invite you to comment with your favourite DB blogs from the week gone by. Please return next week for Nick Westerlund’s LB#173. Till then!
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