[pdal] questions about iterator and buffer semantics

[Chris Foster]

On 29 June 2013 16:16, Chris Foster <chris.foster at roames.com.au> wrote:
> I've submitted a pull request which fixes the problem
> (https://github.com/PDAL/PDAL/pull/146)

On further testing, I've found that disabling the dimension caching between
calls to read() does have a measurable performance impact in some cases.  When
reading an uncompressed las file in small chunks (buffer size of 1000) the
patch above causes a 50% performance degradation or so.

This is a bit surprising as it indicates the cost of dimension lookup in the
schema is rather large, unless there's something else I'm missing.  I'll have
to do some additional performance testing to try to get to the bottom of this.

~Chris