Discussed offline with @RaduBerinde: running each-directive in its own sub-test has two drawbacks:

• it triggers the sub-test machinery inside Go's testing package, which has some time overhead

• it causes extra log lines per directive when running with -v (the default with crdb's CI)

@RaduBerinde reports that at least one sql/opt test duration goes from 1.4s to 2.5s as a result.

Questions:

• what requirement is satisfied by running each directive in its own sub-test? (i.e. what was the motivation for commit 5fd2960?)

• is there a way to satisfy that requirement without a sub-test?