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  1. 14 Jun, 2017 1 commit
    • Tom Lane's avatar
      Disallow set-returning functions inside CASE or COALESCE. · 0436f6bd
      Tom Lane authored 
      When we reimplemented SRFs in commit 69f4b9c8, our initial choice was
to allow the behavior to vary from historical practice in cases where a
SRF call appeared within a conditional-execution construct (currently,
only CASE or COALESCE).  But that was controversial to begin with, and
subsequent discussion has resulted in a consensus that it's better to
throw an error instead of executing the query differently from before,
so long as we can provide a reasonably clear error message and a way to
rewrite the query.

Hence, add a parser mechanism to allow detection of such cases during
parse analysis.  The mechanism just requires storing, in the ParseState,
a pointer to the set-returning FuncExpr or OpExpr most recently emitted
by parse analysis.  Then the parsing functions for CASE and COALESCE can
detect the presence of a SRF in their arguments by noting whether this
pointer changes while analyzing their arguments.  Furthermore, if it does,
it provides a suitable error cursor location for the complaint.  (This
means that if there's more than one SRF in the arguments, the error will
point at the last one to be analyzed not the first.  While connoisseurs of
parsing behavior might find that odd, it's unlikely the average user would
ever notice.)

While at it, we can also provide more specific error messages than before
about some pre-existing restrictions, such as no-SRFs-within-aggregates.
Also, reject at parse time cases where a NULLIF or IS DISTINCT FROM
construct would need to return a set.  We've never supported that, but the
restriction is depended on in more subtle ways now, so it seems wise to
detect it at the start.

Also, provide some documentation about how to rewrite a SRF-within-CASE
query using a custom wrapper SRF.

It turns out that the information_schema.user_mapping_options view
contained an instance of exactly the behavior we're now forbidding; but
rewriting it makes it more clear and safer too.

initdb forced because of user_mapping_options change.

Patch by me, with error message suggestions from Alvaro Herrera and
Andres Freund, pursuant to a complaint from Regina Obe.

Discussion: https://postgr.es/m/000001d2d5de$d8d66170$8a832450$@pcorp.us
      0436f6bd
  3. 13 Jun, 2017 19 commits
  5. 12 Jun, 2017 9 commits
  7. 11 Jun, 2017 2 commits
    • Tom Lane's avatar
      Handle unqualified SEQUENCE NAME options properly in parse_utilcmd.c. · 51893985
      Tom Lane authored 
      generateSerialExtraStmts() was sloppy about handling the case where
SEQUENCE NAME is given with a not-schema-qualified name.  It was generating
a CreateSeqStmt with an unqualified sequence name, and an AlterSeqStmt
whose "owned_by" DefElem contained a T_String Value with a null string
pointer in the schema-name position.  The generated nextval() argument was
also underqualified.  This accidentally failed to fail at runtime, but only
so long as the current default creation namespace at runtime is the right
namespace.  That's bogus; the parse-time transformation is supposed to be
inserting the right schema name in all cases, so as to avoid any possible
skew in that selection.  I'm not sure this could fail in pg_dump's usage,
but it's still wrong; we have had real bugs in this area before adopting
the policy that parse_utilcmd.c should generate only fully-qualified
auxiliary commands.  A slightly lesser problem, which is what led me to
notice this in the first place, is that pprint() dumped core on the
AlterSeqStmt because of the bogus T_String.

Noted while poking into the open problem with ALTER SEQUENCE breaking
pg_upgrade.
      51893985
    • Joe Conway's avatar
      Apply RLS policies to partitioned tables. · 4f7a95be
      Joe Conway authored 
      The new partitioned table capability added a new relkind, namely
RELKIND_PARTITIONED_TABLE. Update fireRIRrules() to apply RLS
policies on RELKIND_PARTITIONED_TABLE as it does RELKIND_RELATION.

In addition, add RLS regression test coverage for partitioned tables.

Issue raised by Fakhroutdinov Evgenievich and patch by Mike Palmiotto.
Regression test editorializing by me.

Discussion: https://postgr.es/m/flat/20170601065959.1486.69906@wrigleys.postgresql.org
      4f7a95be
  9. 10 Jun, 2017 2 commits
  11. 09 Jun, 2017 7 commits