DEEP DISTINCT

[agershun]

I think we can add option flag should AlaSQL make
a) slow deep distrinct operation for nested JSON objects
b) fast distinct operations which will check only first level objects

We can use flag:

SET DEEPDISTINCT ON

to turn it on.

For example:

    var data = [{a:{b:1}},{a:{b:1}}];
    alasql('SET DEEPDISTINCT ON');
    var res = alasql('SELECT DISTINCT * FROM ?',[data]);
    // returns [{a:{b:1}];
    alasql('SET DEEPDISTINCT OFF');
    var res = alasql('SELECT DISTINCT * FROM ?',[data]);
    // returns [{a:{b:1}},{a:{b:1}}] - because objects {b:!} are different

[agershun]

Another crazy idea: add special keyword, like:

    SELECT DEEP DISTINCT * FROM @[{a:{b:1}}, {a:{b:1}}];
    ASSERT @[{a:{b:1}}];
    SELECT DISTINCT * FROM @[{a:{b:1}}, {a:{b:1}}];
    ASSERT @[{a:{b:1}}, {a:{b:1}}];

The same for: DEEP UNION, DEEP INTERSECT, and DEEP EXCEPT...