We, probably, will be even better off by leaving cost model craft to the system.
I recently had to look into various TPC benchmarks and some of them are very non-trivial to cost-estimate. I found at several queries in TPC-DS that join the same table to itself four (4) times. Even triangles (join with itself three times) are hard, squares like these in TPC-DS are even harder.
I recently had to look into various TPC benchmarks and some of them are very non-trivial to cost-estimate. I found at several queries in TPC-DS that join the same table to itself four (4) times. Even triangles (join with itself three times) are hard, squares like these in TPC-DS are even harder.