- LazyFrame.fetch(n_rows: int = 500, type_coercion: bool = True, predicate_pushdown: bool = True, projection_pushdown: bool = True, simplify_expression: bool = True, string_cache: bool = False, no_optimization: bool = False, slice_pushdown: bool = True, common_subplan_elimination: bool = True) DataFrame #
Collect a small number of rows for debugging purposes.
Fetch is like a
collect()operation, but it overwrites the number of rows read by every scan operation. This is a utility that helps debug a query on a smaller number of rows.
Note that the fetch does not guarantee the final number of rows in the DataFrame. Filter, join operations and a lower number of rows available in the scanned file influence the final number of rows.
Collect n_rows from the data sources.
Run type coercion optimization.
Run predicate pushdown optimization.
Run projection pushdown optimization.
Run simplify expressions optimization.
This argument is deprecated. Please set the string cache globally. The argument will be ignored
Turn off optimizations.
Slice pushdown optimization
Will try to cache branching subplans that occur on self-joins or unions.