alamb commented on code in PR #2858: URL: https://github.com/apache/arrow-datafusion/pull/2858#discussion_r929245313
########## datafusion/optimizer/src/rewrite_disjunctive_predicate.rs: ########## @@ -0,0 +1,354 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use crate::{OptimizerConfig, OptimizerRule}; +use datafusion_common::Result; +use datafusion_expr::logical_plan::Filter; +use datafusion_expr::utils::from_plan; +use datafusion_expr::Expr::BinaryExpr; +use datafusion_expr::{Expr, LogicalPlan, Operator}; +use std::sync::Arc; + +#[derive(Clone, PartialEq, Debug)] +enum Predicate { + And { args: Vec<Predicate> }, + Or { args: Vec<Predicate> }, + Other { expr: Box<Expr> }, +} + +fn predicate(expr: &Expr) -> Result<Predicate> { + match expr { + BinaryExpr { left, op, right } => match op { + Operator::And => { + let args = vec![predicate(left)?, predicate(right)?]; + Ok(Predicate::And { args }) + } + Operator::Or => { + let args = vec![predicate(left)?, predicate(right)?]; + Ok(Predicate::Or { args }) + } + _ => Ok(Predicate::Other { + expr: Box::new(BinaryExpr { + left: left.clone(), + op: *op, + right: right.clone(), + }), + }), + }, + _ => Ok(Predicate::Other { + expr: Box::new(expr.clone()), + }), + } +} + +fn normalize_predicate(predicate: Predicate) -> Expr { + match predicate { + Predicate::And { args } => { + assert!(args.len() >= 2); + args.into_iter() + .map(normalize_predicate) + .reduce(Expr::and) + .expect("had more than one arg") + } + Predicate::Or { args } => { + assert!(args.len() >= 2); + assert!(args.len() >= 2); + args.into_iter() + .map(normalize_predicate) + .reduce(Expr::or) + .expect("had more than one arg") + } + Predicate::Other { expr } => *expr, + } +} + +fn rewrite_predicate(predicate: Predicate) -> Predicate { + match predicate { + Predicate::And { args } => { + let mut rewritten_args = Vec::with_capacity(args.len()); + for arg in args.iter() { + rewritten_args.push(rewrite_predicate(arg.clone())); + } + rewritten_args = flatten_and_predicates(rewritten_args); + Predicate::And { + args: rewritten_args, + } + } + Predicate::Or { args } => { + let mut rewritten_args = vec![]; + for arg in args.iter() { + rewritten_args.push(rewrite_predicate(arg.clone())); + } + rewritten_args = flatten_or_predicates(rewritten_args); + delete_duplicate_predicates(&rewritten_args) + } + Predicate::Other { expr } => Predicate::Other { + expr: Box::new(*expr), + }, + } +} + +fn flatten_and_predicates( + and_predicates: impl IntoIterator<Item = Predicate>, +) -> Vec<Predicate> { + let mut flattened_predicates = vec![]; + for predicate in and_predicates { + match predicate { + Predicate::And { args } => { + flattened_predicates + .extend_from_slice(flatten_and_predicates(args).as_slice()); + } + _ => { + flattened_predicates.push(predicate); + } + } + } + flattened_predicates +} + +fn flatten_or_predicates( + or_predicates: impl IntoIterator<Item = Predicate>, +) -> Vec<Predicate> { + let mut flattened_predicates = vec![]; + for predicate in or_predicates { + match predicate { + Predicate::Or { args } => { + flattened_predicates + .extend_from_slice(flatten_or_predicates(args).as_slice()); + } + _ => { + flattened_predicates.push(predicate); + } + } + } + flattened_predicates +} + +fn delete_duplicate_predicates(or_predicates: &[Predicate]) -> Predicate { + let mut shortest_exprs: Vec<Predicate> = vec![]; + let mut shortest_exprs_len = 0; + // choose the shortest AND predicate + for or_predicate in or_predicates.iter() { + match or_predicate { + Predicate::And { args } => { + let args_num = args.len(); + if shortest_exprs.is_empty() || args_num < shortest_exprs_len { + shortest_exprs = (*args).clone(); + shortest_exprs_len = args_num; + } + } + _ => { + // if there is no AND predicate, it must be the shortest expression. + shortest_exprs = vec![or_predicate.clone()]; + break; + } + } + } + + // dedup shortest_exprs + shortest_exprs.dedup(); + + // Check each element in shortest_exprs to see if it's in all the OR arguments. + let mut exist_exprs: Vec<Predicate> = vec![]; + for expr in shortest_exprs.iter() { + let found = or_predicates.iter().all(|or_predicate| match or_predicate { + Predicate::And { args } => args.contains(expr), + _ => or_predicate == expr, + }); + if found { + exist_exprs.push((*expr).clone()); + } + } + if exist_exprs.is_empty() { + return Predicate::Or { + args: or_predicates.to_vec(), + }; + } + + // Rebuild the OR predicate. + // (A AND B) OR A will be optimized to A. + let mut new_or_predicates = vec![]; + for or_predicate in or_predicates.iter() { + match or_predicate { + Predicate::And { args } => { + let mut new_args = (*args).clone(); + new_args.retain(|expr| !exist_exprs.contains(expr)); + if !new_args.is_empty() { + if new_args.len() == 1 { + new_or_predicates.push(new_args[0].clone()); + } else { + new_or_predicates.push(Predicate::And { args: new_args }); + } + } else { + new_or_predicates.clear(); + break; + } + } + _ => { + if exist_exprs.contains(or_predicate) { + new_or_predicates.clear(); + break; + } + } + } + } + if !new_or_predicates.is_empty() { + if new_or_predicates.len() == 1 { + exist_exprs.push(new_or_predicates[0].clone()); + } else { + exist_exprs.push(Predicate::Or { + args: flatten_or_predicates(new_or_predicates), + }); + } + } + + if exist_exprs.len() == 1 { + exist_exprs[0].clone() + } else { + Predicate::And { + args: flatten_and_predicates(exist_exprs), + } + } +} + +#[derive(Default)] +pub struct RewriteDisjunctivePredicate; + +impl RewriteDisjunctivePredicate { + pub fn new() -> Self { + Self::default() + } + fn rewrite_disjunctive_predicate( + &self, + plan: &LogicalPlan, + _optimizer_config: &OptimizerConfig, + ) -> Result<LogicalPlan> { + match plan { + LogicalPlan::Filter(filter) => { + let predicate = predicate(&filter.predicate)?; + let rewritten_predicate = rewrite_predicate(predicate); + let rewritten_expr = normalize_predicate(rewritten_predicate); + Ok(LogicalPlan::Filter(Filter { + predicate: rewritten_expr, + input: Arc::new(self.rewrite_disjunctive_predicate( + &filter.input, + _optimizer_config, + )?), + })) + } + _ => { + let expr = plan.expressions(); Review Comment: 👍 very nice ########## datafusion/optimizer/src/rewrite_disjunctive_predicate.rs: ########## @@ -0,0 +1,429 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use crate::{OptimizerConfig, OptimizerRule}; +use datafusion_common::Result; +use datafusion_expr::logical_plan::Filter; +use datafusion_expr::utils::from_plan; +use datafusion_expr::Expr::BinaryExpr; +use datafusion_expr::{Expr, LogicalPlan, Operator}; +use std::sync::Arc; + +#[derive(Clone, PartialEq, Debug)] +enum Predicate { + And { args: Vec<Predicate> }, + Or { args: Vec<Predicate> }, + Other { expr: Box<Expr> }, +} + +fn predicate(expr: &Expr) -> Result<Predicate> { + match expr { + BinaryExpr { left, op, right } => match op { + Operator::And => { + let args = vec![predicate(left)?, predicate(right)?]; + Ok(Predicate::And { args }) + } + Operator::Or => { + let args = vec![predicate(left)?, predicate(right)?]; + Ok(Predicate::Or { args }) + } + _ => Ok(Predicate::Other { + expr: Box::new(BinaryExpr { + left: left.clone(), + op: *op, + right: right.clone(), + }), + }), + }, + _ => Ok(Predicate::Other { + expr: Box::new(expr.clone()), + }), + } +} + +fn normalize_predicate(predicate: &Predicate) -> Expr { + match predicate { + Predicate::And { args } => { + assert!(args.len() >= 2); + let left = normalize_predicate(&args[0]); + let right = normalize_predicate(&args[1]); + let mut and_expr = BinaryExpr { + left: Box::new(left), + op: Operator::And, + right: Box::new(right), + }; + for arg in args.iter().skip(2) { + and_expr = BinaryExpr { + left: Box::new(and_expr), + op: Operator::And, + right: Box::new(normalize_predicate(arg)), + }; + } + and_expr + } + Predicate::Or { args } => { + assert!(args.len() >= 2); + let left = normalize_predicate(&args[0]); + let right = normalize_predicate(&args[1]); + let mut or_expr = BinaryExpr { + left: Box::new(left), + op: Operator::Or, + right: Box::new(right), + }; + for arg in args.iter().skip(2) { + or_expr = BinaryExpr { + left: Box::new(or_expr), + op: Operator::Or, + right: Box::new(normalize_predicate(arg)), + }; + } + or_expr + } + Predicate::Other { expr } => *expr.clone(), + } +} + +fn rewrite_predicate(predicate: &Predicate) -> Predicate { + match predicate { + Predicate::And { args } => { + let mut rewritten_args = Vec::with_capacity(args.len()); + for arg in args.iter() { + rewritten_args.push(rewrite_predicate(arg)); + } + rewritten_args = flatten_and_predicates(&rewritten_args); + Predicate::And { + args: rewritten_args, + } + } + Predicate::Or { args } => { + let mut rewritten_args = vec![]; + for arg in args.iter() { + rewritten_args.push(rewrite_predicate(arg)); + } + rewritten_args = flatten_or_predicates(&rewritten_args); + delete_duplicate_predicates(&rewritten_args) + } + Predicate::Other { expr } => Predicate::Other { + expr: Box::new(*expr.clone()), + }, + } +} + +fn flatten_and_predicates(and_predicates: &[Predicate]) -> Vec<Predicate> { + let mut flattened_predicates = vec![]; + for predicate in and_predicates { + match predicate { + Predicate::And { args } => { + flattened_predicates + .extend_from_slice(flatten_and_predicates(args).as_slice()); + } + _ => { + flattened_predicates.push(predicate.clone()); + } + } + } + flattened_predicates +} + +fn flatten_or_predicates(or_predicates: &[Predicate]) -> Vec<Predicate> { + let mut flattened_predicates = vec![]; + for predicate in or_predicates { + match predicate { + Predicate::Or { args } => { + flattened_predicates + .extend_from_slice(flatten_or_predicates(args).as_slice()); + } + _ => { + flattened_predicates.push(predicate.clone()); + } + } + } + flattened_predicates +} + +fn delete_duplicate_predicates(or_predicates: &[Predicate]) -> Predicate { + let mut shortest_exprs: Vec<Predicate> = vec![]; + let mut shortest_exprs_len = 0; + // choose the shortest AND predicate Review Comment: > We don't need to check all elements, only the shortest could be the common expression. I don't understand why only the shortest could be the common expression. I am probably missing something. For example, in the following predicate, the common sub expression`(p_partkey = l_partkey OR p_partkey > 5)` is not the shortest ``` ( (p_partkey = l_partkey OR p_partkey > 5) and p_brand = 'Brand#12' ) or ( (p_partkey = l_partkey OR p_partkey > 5) and p_size between 1 and 10 ) or ( (p_partkey = l_partkey OR p_partkey > 5) and p_size between 1 and 15 )"; ``` and yet it could be factored out ``` (p_partkey = l_partkey OR p_partkey > 5) and ( p_brand = 'Brand#12' ) or ( p_size between 1 and 10 ) or ( p_size between 1 and 15 )"; ``` 🤔 ########## datafusion/optimizer/src/rewrite_disjunctive_predicate.rs: ########## @@ -0,0 +1,354 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use crate::{OptimizerConfig, OptimizerRule}; +use datafusion_common::Result; +use datafusion_expr::logical_plan::Filter; +use datafusion_expr::utils::from_plan; +use datafusion_expr::Expr::BinaryExpr; +use datafusion_expr::{Expr, LogicalPlan, Operator}; +use std::sync::Arc; + +#[derive(Clone, PartialEq, Debug)] +enum Predicate { + And { args: Vec<Predicate> }, + Or { args: Vec<Predicate> }, + Other { expr: Box<Expr> }, +} + +fn predicate(expr: &Expr) -> Result<Predicate> { + match expr { + BinaryExpr { left, op, right } => match op { + Operator::And => { + let args = vec![predicate(left)?, predicate(right)?]; + Ok(Predicate::And { args }) + } + Operator::Or => { + let args = vec![predicate(left)?, predicate(right)?]; + Ok(Predicate::Or { args }) + } + _ => Ok(Predicate::Other { + expr: Box::new(BinaryExpr { + left: left.clone(), + op: *op, + right: right.clone(), + }), + }), + }, + _ => Ok(Predicate::Other { + expr: Box::new(expr.clone()), + }), + } +} + +fn normalize_predicate(predicate: Predicate) -> Expr { + match predicate { + Predicate::And { args } => { + assert!(args.len() >= 2); + args.into_iter() + .map(normalize_predicate) + .reduce(Expr::and) + .expect("had more than one arg") + } + Predicate::Or { args } => { + assert!(args.len() >= 2); + assert!(args.len() >= 2); + args.into_iter() + .map(normalize_predicate) + .reduce(Expr::or) + .expect("had more than one arg") + } + Predicate::Other { expr } => *expr, + } +} + +fn rewrite_predicate(predicate: Predicate) -> Predicate { + match predicate { + Predicate::And { args } => { + let mut rewritten_args = Vec::with_capacity(args.len()); + for arg in args.iter() { + rewritten_args.push(rewrite_predicate(arg.clone())); + } + rewritten_args = flatten_and_predicates(rewritten_args); + Predicate::And { + args: rewritten_args, + } + } + Predicate::Or { args } => { + let mut rewritten_args = vec![]; + for arg in args.iter() { + rewritten_args.push(rewrite_predicate(arg.clone())); + } + rewritten_args = flatten_or_predicates(rewritten_args); + delete_duplicate_predicates(&rewritten_args) + } + Predicate::Other { expr } => Predicate::Other { + expr: Box::new(*expr), + }, + } +} + +fn flatten_and_predicates( + and_predicates: impl IntoIterator<Item = Predicate>, +) -> Vec<Predicate> { + let mut flattened_predicates = vec![]; + for predicate in and_predicates { + match predicate { + Predicate::And { args } => { + flattened_predicates + .extend_from_slice(flatten_and_predicates(args).as_slice()); + } + _ => { + flattened_predicates.push(predicate); + } + } + } + flattened_predicates +} + +fn flatten_or_predicates( + or_predicates: impl IntoIterator<Item = Predicate>, +) -> Vec<Predicate> { + let mut flattened_predicates = vec![]; + for predicate in or_predicates { + match predicate { + Predicate::Or { args } => { + flattened_predicates + .extend_from_slice(flatten_or_predicates(args).as_slice()); + } + _ => { + flattened_predicates.push(predicate); + } + } + } + flattened_predicates +} + +fn delete_duplicate_predicates(or_predicates: &[Predicate]) -> Predicate { + let mut shortest_exprs: Vec<Predicate> = vec![]; + let mut shortest_exprs_len = 0; + // choose the shortest AND predicate + for or_predicate in or_predicates.iter() { + match or_predicate { + Predicate::And { args } => { + let args_num = args.len(); + if shortest_exprs.is_empty() || args_num < shortest_exprs_len { + shortest_exprs = (*args).clone(); + shortest_exprs_len = args_num; + } + } + _ => { + // if there is no AND predicate, it must be the shortest expression. + shortest_exprs = vec![or_predicate.clone()]; + break; + } + } + } + + // dedup shortest_exprs + shortest_exprs.dedup(); + + // Check each element in shortest_exprs to see if it's in all the OR arguments. + let mut exist_exprs: Vec<Predicate> = vec![]; + for expr in shortest_exprs.iter() { + let found = or_predicates.iter().all(|or_predicate| match or_predicate { + Predicate::And { args } => args.contains(expr), + _ => or_predicate == expr, + }); + if found { + exist_exprs.push((*expr).clone()); + } + } + if exist_exprs.is_empty() { + return Predicate::Or { + args: or_predicates.to_vec(), + }; + } + + // Rebuild the OR predicate. + // (A AND B) OR A will be optimized to A. + let mut new_or_predicates = vec![]; + for or_predicate in or_predicates.iter() { + match or_predicate { + Predicate::And { args } => { + let mut new_args = (*args).clone(); + new_args.retain(|expr| !exist_exprs.contains(expr)); + if !new_args.is_empty() { + if new_args.len() == 1 { + new_or_predicates.push(new_args[0].clone()); + } else { + new_or_predicates.push(Predicate::And { args: new_args }); + } + } else { + new_or_predicates.clear(); + break; + } + } + _ => { + if exist_exprs.contains(or_predicate) { + new_or_predicates.clear(); + break; + } + } + } + } + if !new_or_predicates.is_empty() { + if new_or_predicates.len() == 1 { + exist_exprs.push(new_or_predicates[0].clone()); + } else { + exist_exprs.push(Predicate::Or { + args: flatten_or_predicates(new_or_predicates), + }); + } + } + + if exist_exprs.len() == 1 { + exist_exprs[0].clone() + } else { + Predicate::And { + args: flatten_and_predicates(exist_exprs), + } + } +} + +#[derive(Default)] +pub struct RewriteDisjunctivePredicate; + +impl RewriteDisjunctivePredicate { + pub fn new() -> Self { + Self::default() + } + fn rewrite_disjunctive_predicate( + &self, + plan: &LogicalPlan, + _optimizer_config: &OptimizerConfig, + ) -> Result<LogicalPlan> { + match plan { + LogicalPlan::Filter(filter) => { + let predicate = predicate(&filter.predicate)?; + let rewritten_predicate = rewrite_predicate(predicate); + let rewritten_expr = normalize_predicate(rewritten_predicate); + Ok(LogicalPlan::Filter(Filter { + predicate: rewritten_expr, + input: Arc::new(self.rewrite_disjunctive_predicate( + &filter.input, + _optimizer_config, + )?), + })) + } + _ => { + let expr = plan.expressions(); + let inputs = plan.inputs(); + let new_inputs = inputs + .iter() + .map(|input| { + self.rewrite_disjunctive_predicate(input, _optimizer_config) + }) + .collect::<Result<Vec<_>>>()?; + from_plan(plan, &expr, &new_inputs) + } + } + } +} + +impl OptimizerRule for RewriteDisjunctivePredicate { + fn optimize( + &self, + plan: &LogicalPlan, + optimizer_config: &mut OptimizerConfig, + ) -> Result<LogicalPlan> { + self.rewrite_disjunctive_predicate(plan, optimizer_config) + } + + fn name(&self) -> &str { + "rewrite_disjunctive_predicate" + } +} + +#[cfg(test)] + +mod tests { + use crate::rewrite_disjunctive_predicate::{ + normalize_predicate, predicate, rewrite_predicate, Predicate, + }; + + use datafusion_common::{Result, ScalarValue}; + use datafusion_expr::{and, col, lit, or}; + + #[test] + fn test_rewrite_predicate() -> Result<()> { + let equi_expr = col("t1.a").eq(col("t2.b")); + let gt_expr = col("t1.c").gt(lit(ScalarValue::Int8(Some(1)))); + let lt_expr = col("t1.d").lt(lit(ScalarValue::Int8(Some(2)))); + let expr = or( + and(equi_expr.clone(), gt_expr.clone()), + and(equi_expr.clone(), lt_expr.clone()), + ); + let predicate = predicate(&expr)?; + assert_eq!( + predicate, + Predicate::Or { + args: vec![ + Predicate::And { + args: vec![ + Predicate::Other { + expr: Box::new(equi_expr.clone()) + }, + Predicate::Other { + expr: Box::new(gt_expr.clone()) + } + ] + }, + Predicate::And { + args: vec![ + Predicate::Other { + expr: Box::new(equi_expr.clone()) + }, + Predicate::Other { + expr: Box::new(lt_expr.clone()) + } + ] + } + ] + } + ); + let rewritten_predicate = rewrite_predicate(predicate); + assert_eq!( Review Comment: 👍 ########## datafusion/optimizer/src/rewrite_disjunctive_predicate.rs: ########## @@ -0,0 +1,429 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use crate::{OptimizerConfig, OptimizerRule}; +use datafusion_common::Result; +use datafusion_expr::logical_plan::Filter; +use datafusion_expr::utils::from_plan; +use datafusion_expr::Expr::BinaryExpr; +use datafusion_expr::{Expr, LogicalPlan, Operator}; +use std::sync::Arc; + +#[derive(Clone, PartialEq, Debug)] +enum Predicate { + And { args: Vec<Predicate> }, + Or { args: Vec<Predicate> }, + Other { expr: Box<Expr> }, +} + +fn predicate(expr: &Expr) -> Result<Predicate> { + match expr { + BinaryExpr { left, op, right } => match op { + Operator::And => { + let args = vec![predicate(left)?, predicate(right)?]; + Ok(Predicate::And { args }) + } + Operator::Or => { + let args = vec![predicate(left)?, predicate(right)?]; + Ok(Predicate::Or { args }) + } + _ => Ok(Predicate::Other { + expr: Box::new(BinaryExpr { + left: left.clone(), + op: *op, + right: right.clone(), + }), + }), + }, + _ => Ok(Predicate::Other { + expr: Box::new(expr.clone()), + }), + } +} + +fn normalize_predicate(predicate: &Predicate) -> Expr { + match predicate { + Predicate::And { args } => { + assert!(args.len() >= 2); + let left = normalize_predicate(&args[0]); + let right = normalize_predicate(&args[1]); + let mut and_expr = BinaryExpr { + left: Box::new(left), + op: Operator::And, + right: Box::new(right), + }; + for arg in args.iter().skip(2) { + and_expr = BinaryExpr { + left: Box::new(and_expr), + op: Operator::And, + right: Box::new(normalize_predicate(arg)), + }; + } + and_expr + } + Predicate::Or { args } => { + assert!(args.len() >= 2); + let left = normalize_predicate(&args[0]); + let right = normalize_predicate(&args[1]); + let mut or_expr = BinaryExpr { + left: Box::new(left), + op: Operator::Or, + right: Box::new(right), + }; + for arg in args.iter().skip(2) { + or_expr = BinaryExpr { + left: Box::new(or_expr), + op: Operator::Or, + right: Box::new(normalize_predicate(arg)), + }; + } + or_expr + } + Predicate::Other { expr } => *expr.clone(), + } +} + +fn rewrite_predicate(predicate: &Predicate) -> Predicate { + match predicate { + Predicate::And { args } => { + let mut rewritten_args = Vec::with_capacity(args.len()); + for arg in args.iter() { + rewritten_args.push(rewrite_predicate(arg)); + } + rewritten_args = flatten_and_predicates(&rewritten_args); + Predicate::And { + args: rewritten_args, + } + } + Predicate::Or { args } => { + let mut rewritten_args = vec![]; + for arg in args.iter() { + rewritten_args.push(rewrite_predicate(arg)); + } + rewritten_args = flatten_or_predicates(&rewritten_args); + delete_duplicate_predicates(&rewritten_args) + } + Predicate::Other { expr } => Predicate::Other { + expr: Box::new(*expr.clone()), + }, + } +} + +fn flatten_and_predicates(and_predicates: &[Predicate]) -> Vec<Predicate> { + let mut flattened_predicates = vec![]; + for predicate in and_predicates { + match predicate { + Predicate::And { args } => { + flattened_predicates + .extend_from_slice(flatten_and_predicates(args).as_slice()); + } + _ => { + flattened_predicates.push(predicate.clone()); + } + } + } + flattened_predicates +} + +fn flatten_or_predicates(or_predicates: &[Predicate]) -> Vec<Predicate> { + let mut flattened_predicates = vec![]; + for predicate in or_predicates { + match predicate { + Predicate::Or { args } => { + flattened_predicates + .extend_from_slice(flatten_or_predicates(args).as_slice()); + } + _ => { + flattened_predicates.push(predicate.clone()); + } + } + } + flattened_predicates +} + +fn delete_duplicate_predicates(or_predicates: &[Predicate]) -> Predicate { + let mut shortest_exprs: Vec<Predicate> = vec![]; + let mut shortest_exprs_len = 0; + // choose the shortest AND predicate Review Comment: That being said, I don't think it is incorrect to pick the shortest predicate, but I do think it may miss potential rewrites. We can always improve it in the future perhaps ########## datafusion/optimizer/src/rewrite_disjunctive_predicate.rs: ########## @@ -0,0 +1,354 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use crate::{OptimizerConfig, OptimizerRule}; +use datafusion_common::Result; +use datafusion_expr::logical_plan::Filter; +use datafusion_expr::utils::from_plan; +use datafusion_expr::Expr::BinaryExpr; +use datafusion_expr::{Expr, LogicalPlan, Operator}; +use std::sync::Arc; + +#[derive(Clone, PartialEq, Debug)] +enum Predicate { + And { args: Vec<Predicate> }, + Or { args: Vec<Predicate> }, + Other { expr: Box<Expr> }, +} + +fn predicate(expr: &Expr) -> Result<Predicate> { + match expr { + BinaryExpr { left, op, right } => match op { + Operator::And => { + let args = vec![predicate(left)?, predicate(right)?]; + Ok(Predicate::And { args }) + } + Operator::Or => { + let args = vec![predicate(left)?, predicate(right)?]; + Ok(Predicate::Or { args }) + } + _ => Ok(Predicate::Other { + expr: Box::new(BinaryExpr { + left: left.clone(), + op: *op, + right: right.clone(), + }), + }), + }, + _ => Ok(Predicate::Other { + expr: Box::new(expr.clone()), + }), + } +} + +fn normalize_predicate(predicate: Predicate) -> Expr { + match predicate { + Predicate::And { args } => { + assert!(args.len() >= 2); + args.into_iter() + .map(normalize_predicate) + .reduce(Expr::and) + .expect("had more than one arg") + } + Predicate::Or { args } => { + assert!(args.len() >= 2); + assert!(args.len() >= 2); Review Comment: ```suggestion ``` Seems like the `assert!` was repeated -- This is an automated message from the Apache Git Service. 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