Module optimizer 

Query optimization passes.

Inspired by Python sqlglot’s optimizer module. Currently implements:

• Constant folding (e.g., 1 + 2 → 3)
• Boolean simplification (e.g., TRUE AND x → x)
• Dead predicate elimination (e.g., WHERE TRUE)
• Subquery unnesting / decorrelation (EXISTS, IN → JOINs)
• Predicate pushdown (WHERE → derived tables / JOIN ON)
• Column qualification (qualify_columns — resolve *, add table qualifiers)
• Type annotation (annotate_types — infer SQL types for all AST nodes)

Future optimizations:

• Join reordering
• Column pruning

Modules

annotate_types

Type annotation pass for SQL expressions.

pushdown_predicates

qualify_columns

Qualify columns optimizer pass.

scope_analysis

Scope analysis for SQL queries.

unnest_subqueries

Functions

optimize

Optimize a SQL statement by applying transformation passes.