Re: knngist patch support

Robert Haas <robertmhaas@gmail.com> writes:
> On Sat, Feb 13, 2010 at 3:02 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> What would probably be the recommended solution for backwards-compatible
>> source code is to convert the actual calls to new style, and then
>> provide a block of macro definitions along the lines of
>> 
>> #if CATALOG_VERSION_NO < something
>> #define SearchSysCache1(...) SearchSysCache(..., 0, 0, 0)
>> #define SearchSysCache2(...) SearchSysCache(..., 0, 0)
>> etc
>> 
>> So that seems okay so far.

> Where would we put this block of code?

*We* wouldn't.  This is a solution that might be used by pg_foundry
projects for instance.  Some people want to distribute loadable modules
for which the same source code can be compiled against multiple PG
releases.  They'd stick those macro definitions, conditionalized as
above, into their own source file.
        regards, tom lane