We use a custom [PEG](src/frontend/sql/grammar.pest) for the `pest` parser generator to compile an SQL query and a `vshard` cluster schema into the planner's intermediate representation (IR).
We use a custom [PEG](sbroad-core/src/frontend/sql/query.pest) for the `pest` parser generator to compile an SQL query and a `vshard` cluster schema into the planner's intermediate representation (IR).
The SQL query passes three main steps:
- the parse tree (PT) iterator, which is produced by the `pest` parser generated for our grammar.
