Обсуждение: pgsql: Improve GRANT documentation to point out that UPDATE and DELETE

Log Message:
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Improve GRANT documentation to point out that UPDATE and DELETE typically
require SELECT privilege as well, since you normally need to read existing
column values within such commands.  This behavior is according to spec,
but we'd never documented it before.  Per gripe from Volkan Yazici.

Tags:
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REL8_1_STABLE

Modified Files:
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    pgsql/doc/src/sgml/ref:
        grant.sgml (r1.50.2.1 -> r1.50.2.2)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/grant.sgml?r1=1.50.2.1&r2=1.50.2.2)