[xquery-talk] Everything is a sequence ...so ....

Michael Kay mike at saxonica.com
Sat Jan 25 01:01:35 PST 2014


The eq operator is easier to optimize because the type conversions it does are much simpler (in particular, exploiting indexes is more difficult). However, because 90% of the time people use "=", optimizers are likely to work hard at it even though it's intrinsically more difficult.

But getting into the habit of using "eq" is something I would recommend because of the better diagnostics when you get things wrong.

Michael Kay
Saxonica


On 25 Jan 2014, at 05:43, Ihe Onwuka <ihe.onwuka at gmail.com> wrote:

> ..are there any drawbacks to always using the general comparison form
> 
> thisThing = ('thatThing')
> 
> rather than
> 
> thisThing eq 'thatThing'
> 
> even when you know that you are dealing with a singleton sequence.
> 
> I am guessing this may be an implementation dependent issue.
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