Throw exception when queries containing non-existence column

Pinot doesn’t give error when users’ queries contain non-existence column in schema, but give empty result. It’s also misleading when users aggregation query is bad but Pinot gives 0.

For certain queries, Pinot should just throw exceptions with messages like Columns [A, B, C] don't exist in schema of table myTable, instead of giving empty results.

[Jackie-Jiang]

Correct. IMO the clean solution should be to enforce the schema on all segments so that they always have the same schema, and prune the bad queries on broker side. When a segment does not have a column in the schema, we can automatically generate the column with default values.

[richardstartin]

The behaviour created by DataSchemaSegmentPruner isn’t generally correct though, if segment 1 of table T has column A and segment 2 has columns A and B, select sum(A),sum(B) from T will ignore segment 1 and produce an incorrect sum over A but a correct sum over B.