[CALCITE-3514] LatticeTest fails when JdbcSchema re-computes JdbcTables

[DonnyZone]

As illustrated in CALCITE-3514, we need to implement JdbcTable's equals() and hashCode() methods.

[amaliujia]

even though this is trying to fix CALCITE-3514, because this is a general purpose equals implementation, it should checks equality of all fields of this class. Same for hashcode.

[julianhyde]

I disagree. Two tables are identical if they have the same name, schema etc. No need to check columns.

The "equals" contract does not say you have to check every field.

[amaliujia]

O I see. So if schema name is the same then it guarantees that two tables will be the same (e.g. no need to check the schema), in that case it would make sense.

I mentioned every field in checking just because I made no assumption beyond this function. Indeed "equals" not require what is checked.

[DonnyZone]

I add a variable in JdbcSchema to trigger the issue.