* Dean Rasheed (dean.a.rash...@gmail.com) wrote: > On 30 January 2015 at 03:40, Stephen Frost <sfr...@snowman.net> wrote: > > * Robert Haas (robertmh...@gmail.com) wrote: > >> On Thu, Jan 29, 2015 at 9:04 PM, Stephen Frost <sfr...@snowman.net> wrote: > >> > A policy grants the ability to SELECT, INSERT, UPDATE, or DELETE rows > >> > which match the relevant policy expression. Existing table rows are > >> > checked against the expression specified via USING, while new rows > >> > that would be created via INSERT or UPDATE are checked against the > >> > expression specified via WITH CHECK. When a USING expression returns > >> > false for a given row, that row is not visible to the user. When a WITH > >> > CHECK expression returns false for a row which is to be added, an error > >> > occurs. > >> > >> Yeah, that's not bad. I think it's an improvement, in fact. > > Yes I like that too. My main concern was that we should be describing > policies in terms of permitting access to the table, not limiting > access, because of the default-deny policy, and this new text clears > that up.
Great, thanks, pushed. > One additional quibble -- it's misleading to say "expression returns > false" here (and later in the check_expression parameter description) > because if the expression returns null, that's also a failure. So it > ought to be "false or null", but perhaps it could just be described in > terms of rows matching the expression, with a separate note to say > that a row only matches a policy expression if that expression returns > true, not false or null. Good point, I've made a few minor changes to address that also, please let me know if you see any issus. Thanks! Stephen
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