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https://issues.apache.org/jira/browse/DRILL-8555?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18134283#comment-18134283
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ASF GitHub Bot commented on DRILL-8555:
---------------------------------------
cgivre commented on code in PR #3086:
URL: https://github.com/apache/drill/pull/3086#discussion_r4414529557
##########
logical/src/main/java/org/apache/drill/common/expression/LiteralExpression.java:
##########
@@ -0,0 +1,47 @@
+/*
+ * 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.
+ */
+package org.apache.drill.common.expression;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+/** A literal that may carry a bound SQL parameter slot in a cached plan. */
+public abstract class LiteralExpression extends LogicalExpressionBase {
+ private int dynamicParamIndex = -1;
+
+ protected LiteralExpression(ExpressionPosition position) {
+ super(position);
+ }
+
+ @JsonIgnore
+ public int getDynamicParamIndex() {
+ return dynamicParamIndex;
+ }
+
+ /** Whether this literal is bound to a zero-based SQL parameter slot. */
+ @JsonIgnore
+ public boolean isDynamicParam() {
+ return dynamicParamIndex >= 0;
+ }
+
+ public void setDynamicParamIndex(int dynamicParamIndex) {
Review Comment:
Ok. That's fine.
> Physical plan cache for parameterized SQL queries
> -------------------------------------------------
>
> Key: DRILL-8555
> URL: https://issues.apache.org/jira/browse/DRILL-8555
> Project: Apache Drill
> Issue Type: New Feature
> Components: Query Planning & Optimization
> Reporter: Letian Jiang
> Priority: Major
>
> h2. Motivation
> Repeated queries that differ only in literals are a common workload, yet each
> query currently requires full planning. This adds unnecessary latency and
> wastes CPU time.
> h2. Brief Design
> Add a per-Drillbit, in-memory plan cache. Drill automatically parameterizes
> eligible SQL queries and reuses a cached physical plan with the current
> literal values, without changes to client queries.
> h2. Plan reuse safety
> * *Engine:* matches the SQL template and checks relevant option changes,
> plugin configuration changes, and whether base table versions still match.
> * *Storage plugin:* explicitly opts in, provides a plan-compatible table
> version, and is responsible for rebuilding its predicate-dependent scan work
> from the rebound expressions.
> h2. Expected benefit
> Short, frequently executed queries such as HBase reads can benefit
> substantially. Analytical queries with significant planning cost can benefit
> as well.
> h2. Implementation status
> A working implementation is available, including HBase, Paimon and Iceberg
> integrations. A pull request will follow.
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