[COMMITTERS] pgsql: Make TRUNCATE ... RESTART IDENTITY restart sequences transaction

Make TRUNCATE ... RESTART IDENTITY restart sequences transactionally. In the previous coding, we simply issued ALTER SEQUENCE RESTART commands, which do not roll back on error. This meant that an error between truncating and committing left the sequences out of sync with the table contents, with

[COMMITTERS] pgsql: Document the dummy_seclabel contrib module.

Document the dummy_seclabel contrib module. KaiGai Kohei, with editing and markup fixes by me. Branch -- master Details --- http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=45768d10e3abd513b4c959efeb5907798f2fac3f Modified Files -- doc/src/sgml/contrib.sgml

[COMMITTERS] pgsql: Further fallout from the MergeAppend patch.

Further fallout from the MergeAppend patch. Fix things so that top-N sorting can be used in child Sort nodes of a MergeAppend node, when there is a LIMIT and no intervening joins or grouping. Actually doing this on the executor side isn't too bad, but it's a bit messier to get the planner to cost