Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

if none columns in window expr are needed, remove the window exprs #2634

Merged
merged 2 commits into from
May 29, 2022
Merged

if none columns in window expr are needed, remove the window exprs #2634

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
34eb9c1
if none columns in window expr are needed, remove the window exprs
HuSen8891 May 28, 2022
597994e
add test case for windo expr eliminate
HuSen8891 May 29, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 12 additions & 0 deletions datafusion/core/src/optimizer/projection_push_down.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -277,6 +277,18 @@ fn optimize_plan(
})?;
}

// none columns in window expr are needed, remove the window expr
if new_window_expr.is_empty() {
return LogicalPlanBuilder::from(optimize_plan(
_optimizer,
input,
required_columns,
true,
_execution_props,
)?)
.build();
};

// for all the retained window expr, find their sort expressions if any, and retain these
exprlist_to_columns(
&find_sort_exprs(&new_window_expr),
Expand Down
135 changes: 135 additions & 0 deletions datafusion/core/tests/sql/window.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -298,3 +298,138 @@ async fn window_partition_by_order_by() -> Result<()> {
assert_batches_eq!(expected, &results);
Ok(())
}

#[tokio::test]
async fn window_expr_eliminate() -> Result<()> {
let ctx = SessionContext::new();

// window expr is not referenced anywhere, eliminate it.
let sql = "WITH _sample_data AS (
SELECT 1 as a, 'aa' AS b
UNION ALL
SELECT 3 as a, 'aa' AS b
UNION ALL
SELECT 5 as a, 'bb' AS b
UNION ALL
SELECT 7 as a, 'bb' AS b
), _data2 AS (
SELECT
row_number() OVER (PARTITION BY s.b ORDER BY s.a) AS seq,
s.a,
s.b
FROM _sample_data s
)
SELECT d.b, MAX(d.a) AS max_a
FROM _data2 d
GROUP BY d.b
ORDER BY d.b;";

let msg = format!("Creating logical plan for '{}'", sql);
let plan = ctx
.create_logical_plan(&("explain ".to_owned() + sql))
.expect(&msg);
let state = ctx.state.read().clone();
let plan = state.optimize(&plan)?;
let expected = vec![
"Explain [plan_type:Utf8, plan:Utf8]",
" Sort: #d.b ASC NULLS LAST [b:Utf8, max_a:Int64;N]",
" Projection: #d.b, #MAX(d.a) AS max_a [b:Utf8, max_a:Int64;N]",
" Aggregate: groupBy=[[#d.b]], aggr=[[MAX(#d.a)]] [b:Utf8, MAX(d.a):Int64;N]",
" Projection: #_data2.a, #_data2.b, alias=d [a:Int64, b:Utf8]",
" Projection: #s.a, #s.b, alias=_data2 [a:Int64, b:Utf8]",
" Projection: #a, #b, alias=s [a:Int64, b:Utf8]",
" Union [a:Int64, b:Utf8]",
" Projection: Int64(1) AS a, Utf8(\"aa\") AS b [a:Int64, b:Utf8]",
" EmptyRelation []",
" Projection: Int64(3) AS a, Utf8(\"aa\") AS b [a:Int64, b:Utf8]",
" EmptyRelation []",
" Projection: Int64(5) AS a, Utf8(\"bb\") AS b [a:Int64, b:Utf8]",
" EmptyRelation []",
" Projection: Int64(7) AS a, Utf8(\"bb\") AS b [a:Int64, b:Utf8]",
" EmptyRelation []",
];
let formatted = plan.display_indent_schema().to_string();
let actual: Vec<&str> = formatted.trim().lines().collect();
assert_eq!(
expected, actual,
"\n\nexpected:\n\n{:#?}\nactual:\n\n{:#?}\n\n",
expected, actual
);

let results = execute_to_batches(&ctx, sql).await;
let expected = vec![
"+----+-------+",
"| b | max_a |",
"+----+-------+",
"| aa | 3 |",
"| bb | 7 |",
"+----+-------+",
];

assert_batches_eq!(expected, &results);

// window expr is referenced by the output, keep it
let sql = "WITH _sample_data AS (
SELECT 1 as a, 'aa' AS b
UNION ALL
SELECT 3 as a, 'aa' AS b
UNION ALL
SELECT 5 as a, 'bb' AS b
UNION ALL
SELECT 7 as a, 'bb' AS b
), _data2 AS (
SELECT
row_number() OVER (PARTITION BY s.b ORDER BY s.a) AS seq,
s.a,
s.b
FROM _sample_data s
)
SELECT d.b, MAX(d.a) AS max_a, max(d.seq)
FROM _data2 d
GROUP BY d.b
ORDER BY d.b;";

let plan = ctx
.create_logical_plan(&("explain ".to_owned() + sql))
.expect(&msg);
let plan = state.optimize(&plan)?;
let expected = vec![
"Explain [plan_type:Utf8, plan:Utf8]",
" Sort: #d.b ASC NULLS LAST [b:Utf8, max_a:Int64;N, MAX(d.seq):UInt64;N]",
" Projection: #d.b, #MAX(d.a) AS max_a, #MAX(d.seq) [b:Utf8, max_a:Int64;N, MAX(d.seq):UInt64;N]",
" Aggregate: groupBy=[[#d.b]], aggr=[[MAX(#d.a), MAX(#d.seq)]] [b:Utf8, MAX(d.a):Int64;N, MAX(d.seq):UInt64;N]",
" Projection: #_data2.seq, #_data2.a, #_data2.b, alias=d [seq:UInt64;N, a:Int64, b:Utf8]",
" Projection: #ROW_NUMBER() PARTITION BY [#s.b] ORDER BY [#s.a ASC NULLS LAST] AS seq, #s.a, #s.b, alias=_data2 [seq:UInt64;N, a:Int64, b:Utf8]",
" WindowAggr: windowExpr=[[ROW_NUMBER() PARTITION BY [#s.b] ORDER BY [#s.a ASC NULLS LAST]]] [ROW_NUMBER() PARTITION BY [#s.b] ORDER BY [#s.a ASC NULLS LAST]:UInt64;N, a:Int64, b:Utf8]",
" Projection: #a, #b, alias=s [a:Int64, b:Utf8]",
" Union [a:Int64, b:Utf8]",
" Projection: Int64(1) AS a, Utf8(\"aa\") AS b [a:Int64, b:Utf8]",
" EmptyRelation []",
" Projection: Int64(3) AS a, Utf8(\"aa\") AS b [a:Int64, b:Utf8]",
" EmptyRelation []",
" Projection: Int64(5) AS a, Utf8(\"bb\") AS b [a:Int64, b:Utf8]",
" EmptyRelation []",
" Projection: Int64(7) AS a, Utf8(\"bb\") AS b [a:Int64, b:Utf8]",
" EmptyRelation []",
];
let formatted = plan.display_indent_schema().to_string();
let actual: Vec<&str> = formatted.trim().lines().collect();
assert_eq!(
expected, actual,
"\n\nexpected:\n\n{:#?}\nactual:\n\n{:#?}\n\n",
expected, actual
);

let results = execute_to_batches(&ctx, sql).await;
let expected = vec![
"+----+-------+------------+",
"| b | max_a | MAX(d.seq) |",
"+----+-------+------------+",
"| aa | 3 | 2 |",
"| bb | 7 | 2 |",
"+----+-------+------------+",
];

assert_batches_eq!(expected, &results);
Ok(())
}