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https://issues.apache.org/jira/browse/PHOENIX-514?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14278328#comment-14278328
]
ASF GitHub Bot commented on PHOENIX-514:
----------------------------------------
Github user JamesRTaylor commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/34#discussion_r22992799
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/compile/IndexColumnExpressionCompiler.java
---
@@ -0,0 +1,302 @@
+/*
+ * 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.phoenix.compile;
+
+import java.sql.SQLException;
+import java.util.Collections;
+import java.util.List;
+
+import org.apache.hadoop.hbase.client.Scan;
+import org.apache.phoenix.compile.GroupByCompiler.GroupBy;
+import org.apache.phoenix.expression.ColumnExpression;
+import org.apache.phoenix.expression.Expression;
+import org.apache.phoenix.jdbc.PhoenixConnection;
+import org.apache.phoenix.parse.AddParseNode;
+import org.apache.phoenix.parse.AndParseNode;
+import org.apache.phoenix.parse.ArrayAllComparisonNode;
+import org.apache.phoenix.parse.ArrayAnyComparisonNode;
+import org.apache.phoenix.parse.ArrayElemRefNode;
+import org.apache.phoenix.parse.CaseParseNode;
+import org.apache.phoenix.parse.CastParseNode;
+import org.apache.phoenix.parse.ColumnDef;
+import org.apache.phoenix.parse.ColumnParseNode;
+import org.apache.phoenix.parse.ComparisonParseNode;
+import org.apache.phoenix.parse.DivideParseNode;
+import org.apache.phoenix.parse.FunctionParseNode;
+import org.apache.phoenix.parse.ModulusParseNode;
+import org.apache.phoenix.parse.MultiplyParseNode;
+import org.apache.phoenix.parse.NamedTableNode;
+import org.apache.phoenix.parse.NotParseNode;
+import org.apache.phoenix.parse.OrParseNode;
+import org.apache.phoenix.parse.ParseNode;
+import org.apache.phoenix.parse.RowValueConstructorParseNode;
+import org.apache.phoenix.parse.SQLParser;
+import org.apache.phoenix.parse.StringConcatParseNode;
+import org.apache.phoenix.parse.SubtractParseNode;
+import org.apache.phoenix.parse.TableName;
+import org.apache.phoenix.schema.PColumn;
+import org.apache.phoenix.schema.PTable;
+import org.apache.phoenix.schema.PTableType;
+import org.apache.phoenix.util.IndexUtil;
+
+/**
+ * Visitor that checks if nodes other than ColumnParseNode are present as
+ * an expression in an index. If the expression is present, then the node
is
+ * not visited but processed as a ColumnParseNode.
+ */
+public class IndexColumnExpressionCompiler extends ExpressionCompiler {
+
+ IndexColumnExpressionCompiler(StatementContext context) {
+ super(context);
+ }
+
+ IndexColumnExpressionCompiler(StatementContext context, boolean
resolveViewConstants) {
+ super(context, resolveViewConstants);
+ }
+
+ IndexColumnExpressionCompiler(StatementContext context, GroupBy
groupBy) {
+ super(context, groupBy);
+ }
+
+ IndexColumnExpressionCompiler(StatementContext context, GroupBy
groupBy, boolean resolveViewConstants) {
+ super(context, groupBy, resolveViewConstants);
+ }
+
+ /**
+ * Returns the compiled expression
+ *
+ * @param node
+ * data table parse node
+ */
+ private Expression getExpression(ParseNode node) throws SQLException {
+ PhoenixConnection connection = this.context.getConnection();
+ PTable indexTable = this.context.getCurrentTable().getTable();
+ NamedTableNode dataTableNode = NamedTableNode.create(null,
TableName.create(indexTable.getParentSchemaName().getString(),
+ indexTable.getParentTableName().getString()),
Collections.<ColumnDef>emptyList());
+ ColumnResolver resolver = FromCompiler.getResolver(dataTableNode,
connection);
+ StatementContext context = new
StatementContext(this.context.getStatement(), resolver, new Scan(), new
SequenceManager(this.context.getStatement()));
+ ExpressionCompiler expressionCompiler = new
ExpressionCompiler(context);
+ return node.accept(expressionCompiler);
+ }
+
+ /**
+ * @return true if current table is an index and there is an expression
that matches the given node
+ */
+ private boolean matchesIndexedExpression(ParseNode node) throws
SQLException {
+ if
(context.getCurrentTable().getTable().getType()!=PTableType.INDEX) {
+ return false;
+ }
+ DataTableNodeRewriter statementRewriter = new
DataTableNodeRewriter();
+ ParseNode dataTableParseNode = node.accept(statementRewriter);
+ Expression dataTableExpression =
getExpression(dataTableParseNode);
+ // if the node matches a column expression
+ if
(ColumnExpression.class.isAssignableFrom(dataTableExpression.getClass())) {
+ return false;
+ }
+ for ( PColumn column :
this.context.getCurrentTable().getTable().getColumns()) {
+ if (column.getExpressionStr()!=null) {
+ ParseNode parseNode =
SQLParser.parseCondition(column.getExpressionStr());
+ Expression expression = getExpression(parseNode);
+ if (expression.equals(dataTableExpression))
+ return true;
+ }
+ }
+ return false;
+ }
+
+ private Expression convertAndVisitParseNode(ParseNode node) throws
SQLException {
+ DataTableNodeRewriter statementRewriter = new
DataTableNodeRewriter();
+ ParseNode dataTableParseNode = node.accept(statementRewriter);
+ Expression expression = getExpression(dataTableParseNode);
+ ColumnParseNode columnParseNode = new ColumnParseNode(null,
IndexUtil.getIndexColumnName(null,String.valueOf(expression.hashCode())), null);
+ return visit(columnParseNode);
+ }
+
+ @Override
+ public boolean visitEnter(ComparisonParseNode node) throws
SQLException {
+ // do not visit this node if it matches an expression that is
indexed, it will be converted to a ColumnParseNode and processed in visitLeave
+ return matchesIndexedExpression(node) ? false :
super.visitEnter(node);
+ }
+
+ @Override
+ public Expression visitLeave(ComparisonParseNode node,
List<Expression> children) throws SQLException {
--- End diff --
Having to specialize every visitorLeave is a bit painful. One possibility
would be to make the wrapGroupByExpression method protected, override it, and
do a super.wrapGroupByExpression() call (and perhaps rename it). I believe that
method is called from every visitorLeave method.
> Support functional indexes
> --------------------------
>
> Key: PHOENIX-514
> URL: https://issues.apache.org/jira/browse/PHOENIX-514
> Project: Phoenix
> Issue Type: Task
> Reporter: James Taylor
> Assignee: Thomas D'Silva
> Labels: enhancement
>
> Instead of only defining the set of columns from the data table that make up
> an index, you should be able to use expressions. For example:
> CREATE INDEX upper_last_name_idx ON person (UPPER(last_name))
> Then in queries that use UPPER(last_name), we can replace them with column
> references to the index table.
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