polars.LazyFrame.show_graph#

LazyFrame.show_graph(
*,
optimized: bool = True,
show: bool = True,
output_path: str | Path | None = None,
raw_output: bool = False,
figsize: tuple[float, float] = (16.0, 12.0),
type_coercion: bool = True,
_type_check: bool = True,
predicate_pushdown: bool = True,
projection_pushdown: bool = True,
simplify_expression: bool = True,
slice_pushdown: bool = True,
comm_subplan_elim: bool = True,
comm_subexpr_elim: bool = True,
cluster_with_columns: bool = True,
collapse_joins: bool = True,
engine: EngineType = 'auto',
plan_stage: PlanStage = 'ir',
_check_order: bool = True,
optimizations: QueryOptFlags = (),
) → str | None[source]#

Show a plot of the query plan.

Note that Graphviz must be installed to render the visualization (if not already present, you can download it here: https://graphviz.org/download).

Parameters:
optimized

Optimize the query plan.

show

Show the figure.

output_path

Write the figure to disk.

raw_output

Return dot syntax. This cannot be combined with show and/or output_path.

figsize

Passed to matplotlib if show == True.

type_coercion

Do type coercion optimization.

Deprecated since version 1.30.0: Use the optimizations parameters.

predicate_pushdown

Do predicate pushdown optimization.

Deprecated since version 1.30.0: Use the optimizations parameters.

projection_pushdown

Do projection pushdown optimization.

Deprecated since version 1.30.0: Use the optimizations parameters.

simplify_expression

Run simplify expressions optimization.

Deprecated since version 1.30.0: Use the optimizations parameters.

slice_pushdown

Slice pushdown optimization.

Deprecated since version 1.30.0: Use the optimizations parameters.

comm_subplan_elim

Will try to cache branching subplans that occur on self-joins or unions.

Deprecated since version 1.30.0: Use the optimizations parameters.

comm_subexpr_elim

Common subexpressions will be cached and reused.

Deprecated since version 1.30.0: Use the optimizations parameters.

cluster_with_columns

Combine sequential independent calls to with_columns.

Deprecated since version 1.30.0: Use the optimizations parameters.

collapse_joins

Collapse a join and filters into a faster join.

Deprecated since version 1.30.0: Use the optimizations parameters.

engine

Select the engine used to process the query (default "auto"):

  • "auto": use the engine set by Config.set_engine_affinity or the POLARS_ENGINE_AFFINITY environment variable, falling back to "in-memory" if unset (this default may change in a future release).

  • "in-memory": use the in-memory engine, this is the default engine.

  • "streaming": use the streaming engine, which processes queries in batches, reducing memory pressure and often outperforming the in-memory engine. This will soon become the default engine of Polars.

  • "gpu": use the CUDA GPU engine (requires an Nvidia GPU and cudf-polars). Pass a GPUEngine object for fine-grained control (e.g. device selection on multi-GPU systems).

If the selected engine cannot run the query, Polars falls back to the in-memory engine.

Note

GPU mode is considered unstable. Not all queries will run successfully on the GPU, however, they should fall back transparently to the default engine if execution is not supported.

Running with POLARS_VERBOSE=1 will provide information if a query falls back (and why).

Note

The GPU engine does not support streaming, if streaming is enabled then GPU execution is switched off.

plan_stage{‘ir’, ‘physical’}

Select the stage to display. Currently only the streaming engine has a separate physical stage, for the other engines both IR and physical are the same.

optimizations

The set of the optimizations considered during query optimization.

Examples

>>> lf = pl.LazyFrame(
...     {
...         "a": ["a", "b", "a", "b", "b", "c"],
...         "b": [1, 2, 3, 4, 5, 6],
...         "c": [6, 5, 4, 3, 2, 1],
...     }
... )
>>> lf.group_by("a", maintain_order=True).agg(pl.all().sum()).sort(
...     "a"
... ).show_graph()
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