cockroachdb

cardinality returns the number of elements in the array. In Postgres, it's recursive, and counts each element in every dimension. Since CockroachDB only supports 1-dimensional arrays right now, the function is similar to array_len

See https://www.postgresql.org/docs/13/functions-array.html

Instructions:

• Add a built-in in https://github.com/cockroachdb/cockroach/blob/master/pkg/sql/sem

It would be great to implement test case reduction strategies in SQLancer itself. The advantage of doing this in SQLancer, rather than an external tool like C-Reduce, is that we have all the information on whether a specific bug is still triggered (e.g., that two queries should yield the same result) and that the reduction can likely go further than when having an external interestingness test (e.