mz_transform/
normalize_ops.rs

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1// Copyright Materialize, Inc. and contributors. All rights reserved.
2//
3// Use of this software is governed by the Business Source License
4// included in the LICENSE file.
5//
6// As of the Change Date specified in that file, in accordance with
7// the Business Source License, use of this software will be governed
8// by the Apache License, Version 2.0.
9
10//! Normalize the structure of various operators.
11
12use mz_expr::MirRelationExpr;
13use mz_expr::visit::Visit;
14
15use crate::TransformCtx;
16
17/// Normalize the structure of various operators.
18#[derive(Debug)]
19pub struct NormalizeOps;
20
21impl crate::Transform for NormalizeOps {
22    fn name(&self) -> &'static str {
23        "NormalizeOps"
24    }
25
26    #[mz_ore::instrument(
27        target = "optimizer",
28        level = "debug",
29        fields(path.segment = "normalize_ops")
30    )]
31    fn actually_perform_transform(
32        &self,
33        relation: &mut MirRelationExpr,
34        _ctx: &mut TransformCtx,
35    ) -> Result<(), crate::TransformError> {
36        // Canonicalize and fuse various operators as a bottom-up transforms.
37        relation.try_visit_mut_post::<_, crate::TransformError>(
38            &mut |expr: &mut MirRelationExpr| {
39                // (a) Might enable fusion in the next step.
40                crate::canonicalization::FlatMapToMap::action(expr);
41                crate::canonicalization::TopKElision::action(expr);
42                // (b) Fuse various like-kinded operators. Might enable further canonicalization.
43                crate::fusion::Fusion::action(expr);
44                // (c) Fuse join trees (might lift in-between Filters).
45                crate::fusion::join::Join::action(expr)?;
46                // (d) Extract column references in Map as Project.
47                crate::canonicalization::ProjectionExtraction::action(expr);
48                // Done!
49                Ok(())
50            },
51        )?;
52        mz_repr::explain::trace_plan(&*relation);
53        Ok(())
54    }
55}
mz_transform/normalize_ops.rs

mz_transform/
normalize_ops.rs
