Schemaless data support

[panarch]

Convert Row to enum with Vec and Map variants.
Make column_defs in Schema optional.
..
e.g.

CREATE TABLE Foo;
INSERT INTO Foo VALUES ('{ "a": "hello", "b": true }'), ('{ "a": 100 }');
SELECT a FROM Foo;

[coveralls]

Pull Request Test Coverage Report for Build 3775416308

• 974 of 1017 (95.77%) changed or added relevant lines in 39 files are covered.
• 28 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.1%) to 98.522%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
core/src/executor/validate.rs	4	5	80.0%
core/src/plan/validate.rs	3	4	75.0%
core/src/result.rs	0	1	0.0%
core/src/data/row.rs	21	23	91.3%
core/src/executor/evaluate/evaluated.rs	6	8	75.0%
core/src/executor/context/row_context.rs	8	11	72.73%
core/src/executor/insert.rs	112	115	97.39%
core/src/executor/fetch.rs	90	94	95.74%
core/src/executor/evaluate/stateless.rs	27	32	84.38%
core/src/store/data_row.rs	12	18	66.67%

Files with Coverage Reduction	New Missed Lines	%
cli/src/print.rs	1	95.55%
core/src/executor/insert.rs	1	96.3%
core/src/executor/aggregate/mod.rs	26	86.39%

Totals
Change from base Build 3756284685:	-0.1%
Covered Lines:	37455
Relevant Lines:	38017

---

💛 - Coveralls

[devgony]

Looks like we cannot unnest nested Map if identical key has both Map and other type

gluesql> CREATE TABLE Items;
Table created

gluesql> INSERT INTO Items VALUES ('{"a": {"x": 1}}');
1 row inserted

gluesql> INSERT INTO Items VALUES ('{"a": 1}');
1 row inserted

gluesql> SELECT * FROM Items;
| a     |
|-------|
| [MAP] |
| 1     |

gluesql> SELECT a['x'] FROM Items limit 1;
| a['x'] |
|--------|
| 1      |

gluesql> SELECT a['x'] FROM Items;
[error] selector requires MAP or LIST types

We may need some function like get_type(columnName)?

SELECT 
CASE 
  WHEN get_type(a) == 'MAP' THEN a['x']
  ELSE a
END
FROM Items;

[panarch]

That sounds nice to have a new function that can retrieve the type of value.
Then, how about TYPEOF..?

SELECT 
    CASE 
        WHEN TYPEOF(a) = 'MAP' THEN a['x']
        ELSE a
    END
FROM Items;

[devgony]

I like that!
TYPEOF sounds better 👍

[devgony]

Is there a way to filter with Map like this?

gluesql> SELECT * FROM Item WHERE obj = '{"cost": 3000}';
-- currently 0 rows

[panarch]

PartialEq between Value::Map(_)s is implemented so it can be supported. we can consider using CAST for now.

SELECT * FROM Item WHERE obj = CAST('{ "cost": 3000 }' AS MAP);

Not supported yet, we need to add MAP cast to Value::try_cast_from_literal.

[ever0de]

It seems good overall. It was an interesting piece of work! thank you!