Doc: add example of type resolution in nested UNIONs. Section 10.5 didn't say explicitly that multiple UNIONs are resolved pairwise. Since the resolution algorithm is described as taking any number of inputs, readers might well think that a query like "select x union select y union select z" would be resolved by considering x, y, and z in one resolution step. But that's not what happens (and I think that behavior is per SQL spec). Add an example clarifying this point.
Per bug #15129 from Philippe Beaudoin. Discussion: https://postgr.es/m/152196085023.32649.9916472370480121...@wrigleys.postgresql.org Branch ------ REL9_4_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/428d2465c2eea7dbccca42f0e15d5f352606776e Modified Files -------------- doc/src/sgml/typeconv.sgml | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)
