MeihanLi commented on code in PR #17177: URL: https://github.com/apache/pinot/pull/17177#discussion_r2625645303
########## pinot-common/src/main/java/org/apache/pinot/common/utils/request/QueryFingerprintVisitor.java: ########## @@ -0,0 +1,307 @@ +/** + * 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.pinot.common.utils.request; + +import java.util.ArrayList; +import java.util.List; +import javax.annotation.Nullable; +import org.apache.calcite.sql.SqlCall; +import org.apache.calcite.sql.SqlDynamicParam; +import org.apache.calcite.sql.SqlJoin; +import org.apache.calcite.sql.SqlLiteral; +import org.apache.calcite.sql.SqlNode; +import org.apache.calcite.sql.SqlNodeList; +import org.apache.calcite.sql.SqlOrderBy; +import org.apache.calcite.sql.SqlSelect; +import org.apache.calcite.sql.SqlWith; +import org.apache.calcite.sql.SqlWithItem; +import org.apache.calcite.sql.fun.SqlCase; +import org.apache.calcite.sql.type.SqlTypeName; +import org.apache.calcite.sql.util.SqlShuttle; + + +/** + * QueryFingerprintVisitor traverses the Calcite SqlNode AST and produces a normalized query fingerprint. + * Implementation is based on Calcite 1.40.0 version. It may change in future versions of Calcite. + * + * <p> + * <ul> + * <li>All data literals are replaced with dynamic parameters (?)</li> + * <li>IN/NOT IN clauses with multiple constants are squashed to a single parameter.</li> + * <li>EXPLAIN PLAN FOR is NOT preserved.</li> + * <li>Symbolic keywords (DISTINCT, ASC, DESC, etc.) and NULL literals are preserved.</li> + * <li>Hints are preserved.</li> + * <li>Window functions: window specification (operand 1) are preserved.</li> + * </ul> + * </p> + */ +public class QueryFingerprintVisitor extends SqlShuttle { + // SqlSelect operand index for hints, see {@link org.apache.calcite.sql.SqlSelect}. + private static final int SQLSELECT_HINTS_OPERAND_INDEX = 11; + + // SqlJoin operand indices, see {@link org.apache.calcite.sql.SqlJoin}. + private static final int SQLJOIN_NATURAL_OPERAND_INDEX = 1; + private static final int SQLJOIN_JOIN_TYPE_OPERAND_INDEX = 2; + private static final int SQLJOIN_CONDITION_TYPE_OPERAND_INDEX = 4; + + private int _dynamicParamIndex = 0; + + @Override + public SqlNode visit(SqlLiteral literal) { + if (shouldPreserveLiteral(literal)) { + return literal; + } + // Replace data literals (numbers, strings, dates, etc.) with dynamic parameters + return new SqlDynamicParam(_dynamicParamIndex++, literal.getParserPosition()); + } + + @Override + public @Nullable SqlNode visit(SqlCall call) { + SqlNode result = call; + switch (call.getKind()) { + case SELECT: + result = visitSelect((SqlSelect) call); + break; + case JOIN: + result = visitJoin((SqlJoin) call); + break; + case WITH: + result = visitWith((SqlWith) call); + break; + case WITH_ITEM: + result = visitWithItem((SqlWithItem) call); + break; + // EXPLAIN PLAN FOR is NOT preserved. + case EXPLAIN: + result = call.getOperandList().get(0).accept(this); + break; + case CASE: + result = visitCase((SqlCase) call); + break; + case ORDER_BY: + result = visitOrderBy((SqlOrderBy) call); + break; + case OVER: + // Window functions: only visit the aggregate function (operand 0). + // Skip the window specification (operand 1) due to its complex structure + // with ORDER BY and frame clauses. This means literals in PARTITION BY, + // ORDER BY, and window frames are preserved rather than replaced. + call.setOperand(0, call.getOperandList().get(0).accept(this)); + result = call; + break; + case IN: + case NOT_IN: + result = visitIn(call); + break; + default: + return super.visit(call); + } + return result; + } + + @Nullable + private SqlNode visitCase(SqlCase sqlCase) { + List<SqlNode> newOperands = new ArrayList<>(); + for (SqlNode child : sqlCase.getOperandList()) { + if (child == null) { + newOperands.add(null); + continue; + } + newOperands.add(child.accept(this)); + } + int i = 0; + for (SqlNode operand : newOperands) { + sqlCase.setOperand(i++, operand); + } + return sqlCase; + } + + @Nullable + private SqlNode visitSelect(SqlSelect select) { + List<SqlNode> newOperands = new ArrayList<>(); + for (SqlNode child : select.getOperandList()) { + newOperands.add(child != null ? child.accept(this) : null); + } + int i = 0; + for (SqlNode operand : newOperands) { + // Preserve hints. + if (i == SQLSELECT_HINTS_OPERAND_INDEX) { + break; + } + select.setOperand(i++, operand); + } + return select; + } + + @Nullable + private SqlNode visitJoin(SqlJoin join) { + List<SqlNode> newOperands = new ArrayList<>(); + for (SqlNode child : join.getOperandList()) { + newOperands.add(child != null ? child.accept(this) : null); + } + int i = 0; + for (SqlNode operand : newOperands) { + // Preserve join metadata literals: + // natural (true/false), joinType (INNER/LEFT/RIGHT/FULL) and conditionType (ON/USING) + // These are structural keywords, not data literals. + if (i == SQLJOIN_NATURAL_OPERAND_INDEX + || i == SQLJOIN_JOIN_TYPE_OPERAND_INDEX + || i == SQLJOIN_CONDITION_TYPE_OPERAND_INDEX) { + i++; + continue; + } + join.setOperand(i++, operand); + } + return join; + } + + @Nullable + private SqlNode visitWith(SqlWith with) { + List<SqlNode> newList = new ArrayList<>(); + for (SqlNode node : with.withList.getList()) { + newList.add(node.accept(this)); + } + SqlNode newBody = with.body.accept(this); + with.setOperand(0, new SqlNodeList(newList, with.withList.getParserPosition())); + with.setOperand(1, newBody); + return with; + } + + /** + * SqlWithItem has four fields: SqlIdentifier name, SqlNodeList + * columnList, SqlNode query, and SqlLiteral recursive. + * We will visit only the columnList and query since: + * - name has already been visited in the SqlWith visit method. + * - recursive is a literal which is a property of the WITH item and not the query itself. + */ + @Nullable + private SqlNode visitWithItem(SqlWithItem withItem) { + if (withItem.columnList != null) { + for (int i = 0; i < withItem.columnList.size(); i++) { + SqlNode column = withItem.columnList.get(i); + if (column != null) { + withItem.columnList.set(i, column.accept(this)); + } + } + } + + if (withItem.query != null) { + SqlNode newQuery = withItem.query.accept(this); + withItem.query = newQuery; + } + + return withItem; + } + + @Nullable + private SqlNode visitOrderBy(SqlOrderBy orderBy) { + return new SqlOrderBy( + orderBy.getParserPosition(), + orderBy.query.accept(this), + orderBy.orderList, + orderBy.offset != null ? orderBy.offset.accept(this) : null, + orderBy.fetch != null ? orderBy.fetch.accept(this) : null); + } + + /** + * Visit IN/NOT IN clause and normalize data literals. + * <p> + * Two cases: + * <ul> + * <li><b>Case 1:</b> All values are data literals → replace entire list with a single ? + * <br>Example: IN (1, 2, 3) → IN (?)</li> + * <li><b>Case 2:</b> Contains any of the following → visit each value individually and replace only data literals: + * <ul> + * <li>Preserved literals (NULL, DISTINCT, ASC, DESC, etc.): IN (1, NULL, 3) → IN (?, NULL, ?)</li> Review Comment: Good point! I've added a squashNullInList option to QueryFingerprintVisitor to address this. The visitor now has two constructors: - QueryFingerprintVisitor() - default behavior, preserves NULL (current behavior) - QueryFingerprintVisitor(boolean squashNullInList) - when true, NULL values in IN-lists are treated as data literals and squashed with other values Behavior: - squashNullInList=false (default): IN (1, NULL, 3) → IN (?, NULL, ?) - squashNullInList=true: IN (1, NULL, 3) → IN (?) The option can be wired up to a broker config in the future if needed. -- 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. 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