Thread: pgsql: Doc: extend warnings about collation-mismatch hazards in postgre

Doc: extend warnings about collation-mismatch hazards in postgres_fdw.

Be a little more vocal about the risks of remote collations not
matching local ones.  Actually fixing these risks seems hard,
and I've given up on the idea that it might be back-patchable.
So the best we can do for the back branches is add documentation.

Per discussion of bug #16583 from Jiří Fejfar.

Discussion: https://postgr.es/m/2438715.1632510693@sss.pgh.pa.us

Branch
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REL_11_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/b274c982db67e6b9b43066b2a63d5c0a3dc2c5b5

Modified Files
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doc/src/sgml/postgres-fdw.sgml | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)