Обсуждение: pgsql: Improve CREATE POLICY documentation

Improve CREATE POLICY documentation

Clarify that SELECT policies are now applied when SELECT rights
are required for a given query, even if the query is an UPDATE or
DELETE query.  Pointed out by Noah.

Additionally, note the risk regarding concurrently open transactions
where a relation which controls access to the rows of another relation
are updated and the rows of the primary relation are also being
modified.  Pointed out by Peter Geoghegan.

Back-patch to 9.5.

Branch
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REL9_5_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/46ae55c372761af5e02082ea934bebcba98040a4

Modified Files
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doc/src/sgml/ref/create_policy.sgml |  113 ++++++++++++++++++++++++++---------
1 file changed, 86 insertions(+), 27 deletions(-)