Skip useless calculation of join RTE column names during EXPLAIN. There's no need for set_simple_column_names() to compute unique column names for join RTEs, because a finished plan tree will not contain any join alias Vars that we could need names for. Its other, internal callers will not pass it any join RTEs anyway, so the upshot is we can just skip join RTEs here.
Aside from getting rid of a klugy against-its-documentation use of set_relation_column_names, this can speed up EXPLAIN substantially when considering many-join queries, because the upper join RTEs tend to have a lot of columns. Sami Imseih, with cosmetic changes by me Discussion: https://postgr.es/m/caa5rz0th3q-0p1pri58z9grg8r8azmeba8o1rtkwhlmjg_c...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/7a80e381d16c642d00ec6146ccdf1262a159c69e Modified Files -------------- src/backend/utils/adt/ruleutils.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)