[postgis] Progress Report

Paul Ramsey pramsey at refractions.net
Fri Jun 15 22:04:45 PDT 2001

Dave has been a very busy guy this week, so there are some nice fruit
hanging on the vine:

- extent(geometry) is an aggregate function so 'select extent(geom) from
tabl' returns the maximum extent of all features, 'select extent(geom)
from tabl group by category' returns the extent of all the features in
each category. Very nice.
- force_2d and force_3d functions, which are useful when pulling data
out of the db, to force the representation to be a particular way. For
example, since the office OGC spec does not have 3d feature, doing
'select force_2d(geom) from tabl' will give you OGC compliant well-known
text representation
- and most impressively, OGC well-known binary (WKB) can now be returned
(in both little and big endian flavours) via wkb_ndr() and wkb_xdr().
not so useful at the SQL commandline, but via the libpq client library,
it is very slick, since geometries can be retrieved without all this
geom->string->geom->string->geom converting. to demonstrate, dave wrote
a little client program which pulls WKB data out of postgresql using
libpq and binary cursors. we tested it using a linux/x86 client and a
solaris server (note the endian mismatch) and it worked great! (this is
cool becuase ordinarily if you pull binary data from a binary cursor on
endian mismatched machines you'll get nothing but gobbledegook. hooray
for WKB!)

Also, Jeff has the dumper/loader nearly done.
And I, release/documentation guy have gotten about halfway through a
re-write of the documentation (this time, in docbook). On my todo is to
finish the re-write, prepare the 0.2 release (including all Dave's
fruit, Jeff's loader/dumper and new doco), and move the source code to
CVS so others can start contributing. I would anticipate 0.2 by the end
of next week. However, if folks are really eager for the new things I
can push just daves stuff out the door ASAP.

Thanks to the Win32 gurus for untangling the mysteries of cygwin. I am
starting to understand why the postgresql people distribute win32
binaries. Perhaps I could prevail upon a Win32 guru to do Win32 builds
as we do releases so we can distribute binaries too?

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