jdye64 commented on code in PR #3222:
URL: https://github.com/apache/arrow-datafusion/pull/3222#discussion_r954375689
##########
datafusion/core/src/execution/context.rs:
##########
@@ -1377,6 +1378,8 @@ impl SessionState {
}
rules.push(Arc::new(ReduceOuterJoin::new()));
rules.push(Arc::new(FilterPushDown::new()));
+ // we do type coercion after filter push down so that we don't push
CAST filters to Parquet
Review Comment:
smart move, that would have been a hard bug to find!
##########
datafusion/optimizer/src/type_coercion.rs:
##########
@@ -0,0 +1,178 @@
+// 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.
+
+//! Optimizer rule for type validation and coercion
+
+use crate::{OptimizerConfig, OptimizerRule};
+use arrow::datatypes::DataType;
+use datafusion_common::{DFSchema, DFSchemaRef, Result};
+use datafusion_expr::binary_rule::coerce_types;
+use datafusion_expr::expr_rewriter::{ExprRewritable, ExprRewriter,
RewriteRecursion};
+use datafusion_expr::logical_plan::builder::build_join_schema;
+use datafusion_expr::logical_plan::JoinType;
+use datafusion_expr::utils::from_plan;
+use datafusion_expr::{cast_if_needed, ExprSchemable};
+use datafusion_expr::{Expr, LogicalPlan};
+
+#[derive(Default)]
+pub struct TypeCoercion {}
+
+impl TypeCoercion {
+ pub fn new() -> Self {
+ Self {}
+ }
+}
+
+impl OptimizerRule for TypeCoercion {
+ fn name(&self) -> &str {
+ "TypeCoercion"
+ }
+
+ fn optimize(
+ &self,
+ plan: &LogicalPlan,
+ optimizer_config: &mut OptimizerConfig,
+ ) -> Result<LogicalPlan> {
+ // optimize child plans first
+ let new_inputs = plan
+ .inputs()
+ .iter()
+ .map(|p| self.optimize(p, optimizer_config))
+ .collect::<Result<Vec<_>>>()?;
+
+ let schema = match new_inputs.len() {
+ 1 => new_inputs[0].schema().clone(),
+ 2 => DFSchemaRef::new(build_join_schema(
+ new_inputs[0].schema(),
+ new_inputs[1].schema(),
+ &JoinType::Inner,
+ )?),
+ _ => DFSchemaRef::new(DFSchema::empty()),
+ };
+
+ let mut expr_rewrite = TypeCoercionRewriter { schema };
+
+ let new_expr = plan
+ .expressions()
+ .into_iter()
+ .map(|expr| expr.rewrite(&mut expr_rewrite))
Review Comment:
Learned something new here today about the expr rewriter
##########
datafusion/expr/src/expr_fn.rs:
##########
@@ -259,6 +260,23 @@ pub fn cast(expr: Expr, data_type: DataType) -> Expr {
}
}
+/// Create a cast expression
+pub fn cast_if_needed(
Review Comment:
Makes sense
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
