citus/src
Philip Dubé 5fccc56d3e Expand the set of aggregates which cannot have LIMIT approximated
Previously we only prevented AVG from being pushed down, but this is incorrect:
- array_agg, while somewhat non sensical to order by, will potentially be missing values
- combinefunc aggregation will raise errors about cstrings not being comparable (while we also can't know if the aggregate is commutative)

This commit limits approximating LIMIT pushdown when ordering by aggregates to:
min, max, sum, count, bit_and, bit_or, every, any
Which means of those we previously supported, we now exclude:
avg, array_agg, jsonb_agg, jsonb_object_agg, json_agg, json_object_agg, hll_add, hll_union, topn_add, topn_union
2020-01-30 17:45:18 +00:00
..
backend Expand the set of aggregates which cannot have LIMIT approximated 2020-01-30 17:45:18 +00:00
include Do not evaluate functions on the coordinator for SELECT queries (#3440) 2020-01-30 08:47:28 +01:00
test/regress Expand the set of aggregates which cannot have LIMIT approximated 2020-01-30 17:45:18 +00:00