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https://issues.apache.org/jira/browse/FLINK-2170?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16262315#comment-16262315
]
ASF GitHub Bot commented on FLINK-2170:
---------------------------------------
Github user twalthr commented on a diff in the pull request:
https://github.com/apache/flink/pull/5043#discussion_r152531212
--- Diff:
flink-connectors/flink-orc/src/main/java/org/apache/flink/orc/OrcTableSource.java
---
@@ -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.
+ */
+
+package org.apache.flink.orc;
+
+import org.apache.flink.annotation.VisibleForTesting;
+import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
+import org.apache.flink.api.common.typeinfo.SqlTimeTypeInfo;
+import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.api.java.DataSet;
+import org.apache.flink.api.java.ExecutionEnvironment;
+import org.apache.flink.api.java.typeutils.RowTypeInfo;
+import org.apache.flink.orc.OrcRowInputFormat.Predicate;
+import org.apache.flink.table.api.TableSchema;
+import org.apache.flink.table.expressions.Attribute;
+import org.apache.flink.table.expressions.BinaryComparison;
+import org.apache.flink.table.expressions.EqualTo;
+import org.apache.flink.table.expressions.Expression;
+import org.apache.flink.table.expressions.GreaterThan;
+import org.apache.flink.table.expressions.GreaterThanOrEqual;
+import org.apache.flink.table.expressions.IsFalse;
+import org.apache.flink.table.expressions.IsNotNull;
+import org.apache.flink.table.expressions.IsNull;
+import org.apache.flink.table.expressions.IsTrue;
+import org.apache.flink.table.expressions.LessThan;
+import org.apache.flink.table.expressions.LessThanOrEqual;
+import org.apache.flink.table.expressions.Literal;
+import org.apache.flink.table.expressions.Not;
+import org.apache.flink.table.expressions.NotEqualTo;
+import org.apache.flink.table.expressions.Or;
+import org.apache.flink.table.expressions.UnaryExpression;
+import org.apache.flink.table.sources.BatchTableSource;
+import org.apache.flink.table.sources.FilterableTableSource;
+import org.apache.flink.table.sources.ProjectableTableSource;
+import org.apache.flink.table.sources.TableSource;
+import org.apache.flink.types.Row;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hive.ql.io.sarg.PredicateLeaf;
+import org.apache.orc.TypeDescription;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * A TableSource to read ORC files.
+ *
+ * <p>The {@link OrcTableSource} supports projection and filter
push-down.</p>
+ *
+ * <p>An {@link OrcTableSource} is used as shown in the example below.
+ *
+ * <pre>
+ * {@code
+ * String path = "file:///my/data/file.orc";
+ * String schema =
"struct<col1:boolean,col2:tinyint,col3:smallint,col4:int>"
+ * OrcTableSource orcSrc = new OrcTableSource(path, schema);
+ * tEnv.registerTableSource("orcTable", orcSrc);
+ * Table res = tableEnv.sql("SELECT * FROM orcTable");
+ * }
+ * </pre>
+ */
+public class OrcTableSource
+ implements BatchTableSource<Row>, ProjectableTableSource<Row>,
FilterableTableSource<Row> {
+
+ private static final int DEFAULT_BATCH_SIZE = 1024;
+
+ // path to read ORC files from
+ private final String path;
+ // schema of the ORC file
+ private final TypeDescription orcSchema;
+ // the schema of the Table
+ private final TableSchema tableSchema;
+ // the configuration to read the file
+ private final Configuration orcConfig;
+ // the number of rows to read in a batch
+ private final int batchSize;
+
+ // type information of the data returned by the InputFormat
+ private final RowTypeInfo typeInfo;
+ // list of selected ORC fields to return
+ private final int[] selectedFields;
+ // list of predicates to apply
+ private final Predicate[] predicates;
+
+ /**
+ * Creates an OrcTableSouce with empty configuration.
+ *
+ * @param path The path to read the ORC files from.
+ * @param orcSchema The schema of the ORC files as String.
+ */
+ public OrcTableSource(String path, String orcSchema) {
+ this(path, orcSchema, new Configuration(), DEFAULT_BATCH_SIZE);
+ }
+
+ /**
+ * Creates an OrcTableSource from an ORC schema string.
+ *
+ * @param path The path to read the ORC files from.
+ * @param orcSchema The schema of the ORC files as String.
+ * @param orcConfig The configuration to read the ORC files.
+ */
+ public OrcTableSource(String path, String orcSchema, Configuration
orcConfig) {
+ this(path, TypeDescription.fromString(orcSchema), orcConfig,
DEFAULT_BATCH_SIZE);
+ }
+
+ /**
+ * Creates an OrcTableSource from an ORC schema string.
+ *
+ * @param path The path to read the ORC files from.
+ * @param orcSchema The schema of the ORC files as String.
+ * @param orcConfig The configuration to read the ORC files.
+ * @param batchSize The number of Rows to read in a batch, default is
1000.
+ */
+ public OrcTableSource(String path, String orcSchema, Configuration
orcConfig, int batchSize) {
+ this(path, TypeDescription.fromString(orcSchema), orcConfig,
batchSize);
+ }
+
+ /**
+ * Creates an OrcTableSouce from an ORC TypeDescription.
+ *
+ * @param path The path to read the ORC files from.
+ * @param orcSchema The schema of the ORC files as TypeDescription.
+ * @param orcConfig The configuration to read the ORC files.
+ * @param batchSize The number of Rows to read in a batch, default is
1000.
+ */
+ public OrcTableSource(String path, TypeDescription orcSchema,
Configuration orcConfig, int batchSize) {
+ this(path, orcSchema, orcConfig, batchSize, null, null);
+ }
+
+ private OrcTableSource(String path, TypeDescription orcSchema,
Configuration orcConfig,
+ int batchSize, int[]
selectedFields, Predicate[] predicates) {
+
+ this.path = path;
+ this.orcSchema = orcSchema;
+ this.orcConfig = orcConfig;
+ this.batchSize = batchSize;
+ this.selectedFields = selectedFields;
+ this.predicates = predicates;
+
+ // determine the type information from the ORC schema
+ RowTypeInfo typeInfoFromSchema = (RowTypeInfo)
OrcUtils.schemaToTypeInfo(this.orcSchema);
+
+ // set return type info
+ if (selectedFields == null) {
+ this.typeInfo = typeInfoFromSchema;
+ } else {
+ this.typeInfo =
RowTypeInfo.projectFields(typeInfoFromSchema, selectedFields);
+ }
+
+ // create a TableSchema that corresponds to the ORC schema
+ this.tableSchema = new TableSchema(
+ typeInfoFromSchema.getFieldNames(),
+ typeInfoFromSchema.getFieldTypes()
+ );
+ }
+
+ @Override
+ public DataSet<Row> getDataSet(ExecutionEnvironment execEnv) {
+ OrcRowInputFormat orcIF = buildOrcInputFormat();
+ if (selectedFields != null) {
+ orcIF.selectFields(selectedFields);
+ }
+ if (predicates != null) {
+ for (OrcRowInputFormat.Predicate pred : predicates) {
+ orcIF.addPredicate(pred);
+ }
+ }
+ return execEnv.createInput(orcIF);
+ }
+
+ @VisibleForTesting
+ protected OrcRowInputFormat buildOrcInputFormat() {
+ return new OrcRowInputFormat(path, orcSchema, orcConfig,
batchSize);
+ }
+
+ @Override
+ public TypeInformation<Row> getReturnType() {
+ return typeInfo;
+ }
+
+ @Override
+ public TableSchema getTableSchema() {
+ return this.tableSchema;
+ }
+
+ @Override
+ public TableSource<Row> projectFields(int[] selectedFields) {
+ // create a copy of the OrcTableSouce with new selected fields
+ return new OrcTableSource(path, orcSchema, orcConfig,
batchSize, selectedFields, predicates);
+ }
+
+ @Override
+ public TableSource<Row> applyPredicate(List<Expression> predicates) {
+ ArrayList<Predicate> orcPredicates = new ArrayList<>();
+
+ // we do not remove any predicates from the list because ORC
does not fully apply predicates
+ for (Expression pred : predicates) {
+ Predicate orcPred = toOrcPredicate(pred);
+ if (orcPred != null) {
+ orcPredicates.add(orcPred);
+ }
+ }
+
+ return new OrcTableSource(path, orcSchema, orcConfig,
batchSize, selectedFields, orcPredicates.toArray(new Predicate[]{}));
+ }
+
+ @Override
+ public boolean isFilterPushedDown() {
+ return this.predicates != null;
+ }
+
+ @Override
+ public String explainSource() {
+ return "OrcFile[path=" + path + ", schema=" + orcSchema + ",
filter=" + predicateString() + "]";
+ }
+
+ private String predicateString() {
+ if (predicates != null) {
+ return "AND(" + Arrays.toString(predicates) + ")";
+ } else {
+ return "TRUE";
+ }
+ }
+
+ // Predicate conversion for filter push-down.
+
+ private Predicate toOrcPredicate(Expression pred) {
+ if (pred instanceof Or) {
+ Predicate c1 = toOrcPredicate(((Or) pred).left());
+ Predicate c2 = toOrcPredicate(((Or) pred).right());
+ if (c1 == null || c2 == null) {
+ return null;
+ } else {
+ return new OrcRowInputFormat.Or(c1, c2);
+ }
+ } else if (pred instanceof Not) {
+ Predicate c = toOrcPredicate(((Not) pred).child());
+ if (c == null) {
+ return null;
+ } else {
+ return new OrcRowInputFormat.Not(c);
+ }
+ } else if (pred instanceof BinaryComparison) {
+
+ BinaryComparison binComp = (BinaryComparison) pred;
+
+ if (!isValid(binComp)) {
+ // not a valid predicate
+ return null;
+ }
+ PredicateLeaf.Type litType = getLiteralType(binComp);
+ if (litType == null) {
+ // unsupported literal type
+ return null;
+ }
+
+ boolean literalOnRight = literalOnRight(binComp);
+ String colName = getColumnName(binComp);
+ Serializable literal = (Serializable)
getLiteral(binComp);
+
+ if (pred instanceof EqualTo) {
+ return new OrcRowInputFormat.Equals(colName,
litType, literal);
+ } else if (pred instanceof NotEqualTo) {
+ return new OrcRowInputFormat.Not(
+ new OrcRowInputFormat.Equals(colName,
litType, literal));
+ } else if (pred instanceof GreaterThan) {
+ if (literalOnRight) {
+ return new OrcRowInputFormat.Not(
+ new
OrcRowInputFormat.LessThanEquals(colName, litType, literal));
+ } else {
+ return new
OrcRowInputFormat.LessThan(colName, litType, literal);
+ }
+ } else if (pred instanceof GreaterThanOrEqual) {
+ if (literalOnRight) {
+ return new OrcRowInputFormat.Not(
+ new
OrcRowInputFormat.LessThan(colName, litType, literal));
+ } else {
+ return new
OrcRowInputFormat.LessThanEquals(colName, litType, literal);
+ }
+ } else if (pred instanceof LessThan) {
+ if (literalOnRight) {
+ return new
OrcRowInputFormat.LessThan(colName, litType, literal);
+ } else {
+ return new OrcRowInputFormat.Not(
+ new
OrcRowInputFormat.LessThanEquals(colName, litType, literal));
+ }
+ } else if (pred instanceof LessThanOrEqual) {
+ if (literalOnRight) {
+ return new
OrcRowInputFormat.LessThanEquals(colName, litType, literal);
+ } else {
+ return new OrcRowInputFormat.Not(
+ new
OrcRowInputFormat.LessThan(colName, litType, literal));
+ }
+ } else {
+ // unsupported predicate
+ return null;
+ }
+ } else if (pred instanceof UnaryExpression) {
+
+ UnaryExpression unary = (UnaryExpression) pred;
+ if (!isValid(unary)) {
+ // not a valid predicate
+ return null;
+ }
+ PredicateLeaf.Type colType =
toOrcType(((UnaryExpression) pred).child().resultType());
+ if (colType == null) {
+ // unsupported type
+ return null;
+ }
+
+ String colName = getColumnName(unary);
+
+ if (pred instanceof IsNull) {
--- End diff --
I don't know how the ORC predicates are evaluated but if they comply with
SQLs three-valued logic you cannot use this transformations. See:
https://en.wikibooks.org/wiki/Structured_Query_Language/NULLs_and_the_Three_Valued_Logic#Step_2:_Boolean_Operations_within_3VL
and `ScalarOperators`.
> Add OrcTableSource
> ------------------
>
> Key: FLINK-2170
> URL: https://issues.apache.org/jira/browse/FLINK-2170
> Project: Flink
> Issue Type: New Feature
> Components: Table API & SQL
> Affects Versions: 0.9
> Reporter: Fabian Hueske
> Assignee: Usman Younas
> Priority: Minor
> Labels: starter
>
> Add a {{OrcTableSource}} to read data from an ORC file. The
> {{OrcTableSource}} should implement the {{ProjectableTableSource}}
> (FLINK-3848) and {{FilterableTableSource}} (FLINK-3849) interfaces.
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