pgsql: Support boolean columns in functional-dependency statistics.

2017-12-04 Thread Tom Lane
Support boolean columns in functional-dependency statistics. There's no good reason that the multicolumn stats stuff shouldn't work on booleans. But it looked only for "Var = pseudoconstant" clauses, and it will seldom find those for boolean Vars, since earlier phases of planning will fold "boolv

pgsql: Support boolean columns in functional-dependency statistics.

2017-12-04 Thread Tom Lane
Support boolean columns in functional-dependency statistics. There's no good reason that the multicolumn stats stuff shouldn't work on booleans. But it looked only for "Var = pseudoconstant" clauses, and it will seldom find those for boolean Vars, since earlier phases of planning will fold "boolv