[AST Builder] Implement Index by Expression in Select
seonghun-dev opened this issue · comments
Description
Implements ast builders for index_by Expression
They take a similar form to index hints in traditional SQL,
but while in SQL these index hints can be ignored at the option of the optimizer,
in GlueSQL Query Builder they are generated rather than ignored
because they are part of the actual query generation.
What is Index hint in SQL
MySQL
Oracle
- Write a hint comment on the first line of the SELECT clause to give it the proper index
SELECT /*+ INDEX(a EMP_IDX02) */ a.empno , a.ename , a.hiredate FROM emp aFSM Chart
Current FSM Chart (Exclude Detail)
New FSM Chart (Exclude Detail)
In index Node FSM
The interior of the node in the index consists of another FSM.
Prevent chaining from becoming too long.
Task
Index Hint Works With Update Expression, But in this Issue will be limit to Select Expression
- Add Index Node to Select FSM
- Add Use Index Node
- Add Primary Key Node
- Add Non clustered Node
The following tests should be passed:
Index By
#[test]
fn test_index() {
let sql = "
SELECT * FROM Player
WHERE name IN (
SELECT * FROM Player WHERE id = 1
)";
let index_node = use_index().primary_key("id");
let query_node = table("Player")
.select()
.index_by(index_node)
.filter("id".eq(1));
let query_builder = table("Player")
.select()
.filter("name".in_list(subquery))
.build();
let actual = plan(&storage, query_builder);
let expected = {
let subquery = Query {
body: SetExpr::Select(Box::new(Select {
projection: vec![SelectItem::Wildcard],
from: TableWithJoins {
relation: TableFactor::Table {
name: "Player".to_owned(),
alias: None,
index: Some(IndexItem::PrimaryKey(expr("1"))),
},
joins: Vec::new(),
},
selection: None,
group_by: Vec::new(),
having: None,
})),
limit: None,
offset: None,
order_by: Vec::new(),
};
};
}
which storage types do actually support the index?
which storage types do actually support the index?
Currently the only storage which supports non clustered index is SledStorage.