31 lines
753 B
OCaml
31 lines
753 B
OCaml
type logical_plan =
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| Scan of string (* Table name *)
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| Filter of logical_plan * condition
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| Join of logical_plan * Ast.join_type * logical_plan
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and condition =
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| Condition of string
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let rec generate_from_clause tables =
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match tables with
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| [Ast.Table(name)] -> Scan(name)
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| [Ast.Join(left, j_type, right, _)] ->
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Join(
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generate_from_clause [left],
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j_type,
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generate_from_clause [right]
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)
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| _ -> failwith "Unsupported table structure"
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let generate_logical_plan ast =
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match ast with
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| Ast.Query(Select(_, tables)) ->
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let base_plan = generate_from_clause tables in
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base_plan
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(*let evaluate_plan plan =
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match plan with
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| Scan(table) ->
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| _ -> failwith "Unsupported plan"
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*)
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