Where am I?

The latest release of cq is 3.2.2. This XQuery tool now includes support for XQuery profiling, using the new profiling API, so MarkLogic Server 3.2 is required. The profiler has already been extremely useful: so far, we've used it in several projects where we've improved performance by 3-10x. Each project has been finished in a week or less.

It's a rare week when I don't discover some new corner of the language that I didn't know about before. Did you know about per-variable typing?

let $a as xs:integer := 1
return $a + 2

=> 3

Sounds useless, doesn't it? But just like function-parameter typing, it could prevent errors. Think about this:

let $a as element(ArticleTitle) :=
  doc($ID)/MedlineCitation/Article/ArticleTitle
return $a

Now we have a guarantee that there will be exactly one ArticleTitle. Anything else will cause an error:

XDMP-AS: let $a as element(ArticleTitle) :=
  doc($ID)/child::MedlineCitation/child::Article/child::ArticleTitle
  return $a -- Invalid coercion: () as element(ArticleTitle)

Nice, isn't it?

I'm in NYC, teaching a developer course. There's a little bit of snow on the ground, and everyone wants me to drink stout.

Stephen has written a book on XQuery. Unfortunately, I haven't read it yet.

Happy chance puts me in London on the last two nights of East London CAMRA's Pig's Ear festival. I'm here to teach a 5-day session on XQuery and MarkLogic Server, but that doesn't start until Monday. So I have time for another.



I'm using Hilton points to stay at the Waldorf, these first two nights. Then I'll move into a cheaper place for work. To get to the Pig's Ear, I walked up to Bloomsbury Square, then took the 55 bus to Hackney Town Hall. The festival was in a place called Ocean, across Mare St from the Town Hall (and from the Hackney Empire) - in other words, quite far from LondonLand. I suspect that I wasn't the only American tourist in the crowd, but it was probably close.

The Pig's Ear has been on hiatus for a few years, but I've been once before, when it was in Stratford (no Avon please - we're Londoners). The new hall is a bit sterile, compared to Stratford Town Hall, but it does have much more room. Stratford was always standing only, while Ocean seems to have enough seating for a much larger crowd. The festival beers still tend toward "winter warmers" - strong stuff. That isn't my favorite style: these days I prefer milds. I did try "Night on Mare Street", and found it dangerously easy to drink. But I managed to try every mild on the program, too - St Augustine's Tower was nice. I also tried several cloudy halves from the cider and perry counter. That's good stuff, and it's impossible to find in the USA. It's impossible to find through most of the UK, too. No, the processed stuff doesn't count. Sorry.

But you didn't come here to listen to me rant - you came for a pint. Cheers!