On 10/16/18 07:32, Christoph Berg wrote:
>> 2. You seem to be building packages for PG from 11 back to 9.3. For that
>> range of PG versions, it would be possible to add the -Psaxon-examples
...
>> It's actually safe to add -Psaxon-examples when building for any PG
>> version back to 8.4. Before 8.4, those examples can't be included
> I'm not really following how that relates to the range of PG versions?
> Because it's "only" 8.4+ ?
The saxon-examples functions are declared with SQL syntax that didn't
exist pre-8.4, so they would just be rejected as syntax errors in 8.3
or 8.2.
The documentation illustrating how to call them uses named-parameter
notation with => so it works as far back as 9.5, and with a simple
substitution of := for => they can be called the same way as far back
as 9.0. But the illustrations also show FROM clauses with LATERAL or
with a function referring to earlier entries, which is only possible
in 9.3+.
So the saxon-examples PG version range dependency boils down to:
* the functions can be built and installed in any version 8.4 and up
* they are easy to use in 9.5 and up, following exactly the illustrations
in the docs
* they are almost as easy to use in 9.3 and 9.4, changing => to :=
* from 9.2 back to 8.4, they work, but require increasing devilish
cleverness to write SQL queries that use them.
-Chap