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Posted to commits@iotdb.apache.org by ji...@apache.org on 2025/01/17 11:00:32 UTC
(iotdb) branch remove_attr_col created (now c2a7b4fbe41)
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jiangtian pushed a change to branch remove_attr_col
in repository https://gitbox.apache.org/repos/asf/iotdb.git
at c2a7b4fbe41 Remove attribute columns after attributes are updated
This branch includes the following new commits:
new c2a7b4fbe41 Remove attribute columns after attributes are updated
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(iotdb) 01/01: Remove attribute columns after attributes are updated
Posted by ji...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
jiangtian pushed a commit to branch remove_attr_col
in repository https://gitbox.apache.org/repos/asf/iotdb.git
commit c2a7b4fbe41b63277e0d3ec744c6a7bd465e1bcf
Author: Tian Jiang <jt...@163.com>
AuthorDate: Fri Jan 17 19:00:21 2025 +0800
Remove attribute columns after attributes are updated
---
.../iotdb/it/env/cluster/node/DataNodeWrapper.java | 8 +++
.../it/session/IoTDBSessionRelationalIT.java | 82 ++++++++++++++++++++++
.../plan/analyze/schema/SchemaValidator.java | 1 +
.../relational/sql/ast/WrappedInsertStatement.java | 78 ++++++++++++--------
.../plan/statement/crud/InsertBaseStatement.java | 50 +++++++++++++
.../crud/InsertMultiTabletsStatement.java | 11 +++
.../plan/statement/crud/InsertRowStatement.java | 7 ++
.../crud/InsertRowsOfOneDeviceStatement.java | 5 ++
.../plan/statement/crud/InsertRowsStatement.java | 11 +++
.../plan/statement/crud/InsertTabletStatement.java | 10 +++
.../storageengine/dataregion/wal/io/WALReader.java | 2 +-
11 files changed, 235 insertions(+), 30 deletions(-)
diff --git a/integration-test/src/main/java/org/apache/iotdb/it/env/cluster/node/DataNodeWrapper.java b/integration-test/src/main/java/org/apache/iotdb/it/env/cluster/node/DataNodeWrapper.java
index 3df21cb42a6..6bf36bf969a 100644
--- a/integration-test/src/main/java/org/apache/iotdb/it/env/cluster/node/DataNodeWrapper.java
+++ b/integration-test/src/main/java/org/apache/iotdb/it/env/cluster/node/DataNodeWrapper.java
@@ -145,6 +145,14 @@ public class DataNodeWrapper extends AbstractNodeWrapper {
return workDirFilePath("data/datanode/system/schema", IoTDBStartCheck.PROPERTIES_FILE_NAME);
}
+ public String getDataDir() {
+ return getNodePath() + File.separator + "data";
+ }
+
+ public String getWalDir() {
+ return getDataDir() + File.separator + "datanode" + File.separator + "wal";
+ }
+
@Override
protected MppJVMConfig initVMConfig() {
return MppJVMConfig.builder()
diff --git a/integration-test/src/test/java/org/apache/iotdb/relational/it/session/IoTDBSessionRelationalIT.java b/integration-test/src/test/java/org/apache/iotdb/relational/it/session/IoTDBSessionRelationalIT.java
index 1f70341892b..9ca071fc17d 100644
--- a/integration-test/src/test/java/org/apache/iotdb/relational/it/session/IoTDBSessionRelationalIT.java
+++ b/integration-test/src/test/java/org/apache/iotdb/relational/it/session/IoTDBSessionRelationalIT.java
@@ -18,10 +18,16 @@
*/
package org.apache.iotdb.relational.it.session;
+import org.apache.iotdb.commons.schema.table.column.TsTableColumnCategory;
+import org.apache.iotdb.db.queryengine.plan.planner.plan.node.write.RelationalInsertRowsNode;
+import org.apache.iotdb.db.queryengine.plan.planner.plan.node.write.RelationalInsertTabletNode;
+import org.apache.iotdb.db.storageengine.dataregion.wal.buffer.WALEntry;
+import org.apache.iotdb.db.storageengine.dataregion.wal.io.WALReader;
import org.apache.iotdb.isession.ISession;
import org.apache.iotdb.isession.ITableSession;
import org.apache.iotdb.isession.SessionDataSet;
import org.apache.iotdb.it.env.EnvFactory;
+import org.apache.iotdb.it.env.cluster.node.DataNodeWrapper;
import org.apache.iotdb.it.framework.IoTDBTestRunner;
import org.apache.iotdb.itbase.category.TableClusterIT;
import org.apache.iotdb.itbase.category.TableLocalStandaloneIT;
@@ -43,6 +49,8 @@ import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.runner.RunWith;
+import java.io.File;
+import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.time.LocalDate;
import java.util.ArrayList;
@@ -56,6 +64,7 @@ import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
@RunWith(IoTDBTestRunner.class)
@@ -1529,4 +1538,77 @@ public class IoTDBSessionRelationalIT {
assertEquals(30, cnt);
}
}
+
+ @Test
+ public void testAttrColumnRemoved()
+ throws IoTDBConnectionException, StatementExecutionException, IOException {
+ EnvFactory.getEnv().cleanClusterEnvironment();
+ EnvFactory.getEnv().getConfig().getCommonConfig().setWalMode("SYNC");
+ EnvFactory.getEnv().initClusterEnvironment();
+ try (ITableSession session = EnvFactory.getEnv().getTableSessionConnection()) {
+ session.executeNonQueryStatement("create database if not exists db1");
+ session.executeNonQueryStatement("use db1");
+ session.executeNonQueryStatement(
+ "CREATE TABLE remove_attr_col (tag1 string tag, attr1 string attribute, "
+ + "m1 double "
+ + "field)");
+
+ // insert tablet to WAL
+ List<IMeasurementSchema> schemaList = new ArrayList<>();
+ schemaList.add(new MeasurementSchema("tag1", TSDataType.STRING));
+ schemaList.add(new MeasurementSchema("attr1", TSDataType.STRING));
+ schemaList.add(new MeasurementSchema("m1", TSDataType.DOUBLE));
+ final List<ColumnCategory> columnTypes =
+ Arrays.asList(ColumnCategory.TAG, ColumnCategory.ATTRIBUTE, ColumnCategory.FIELD);
+
+ long timestamp = 0;
+ Tablet tablet =
+ new Tablet(
+ "remove_attr_col",
+ IMeasurementSchema.getMeasurementNameList(schemaList),
+ IMeasurementSchema.getDataTypeList(schemaList),
+ columnTypes);
+
+ for (int rowIndex = 0; rowIndex < 10; rowIndex++) {
+ tablet.addTimestamp(rowIndex, timestamp);
+ tablet.addValue("tag1", rowIndex, "tag:1");
+ tablet.addValue("attr1", rowIndex, "attr:" + timestamp);
+ tablet.addValue("m1", rowIndex, timestamp * 1.0);
+ timestamp++;
+ }
+ session.insert(tablet);
+ tablet.reset();
+
+ // insert records to WAL
+ session.executeNonQueryStatement(
+ "INSERT INTO remove_attr_col (time, tag1, attr1, m1) VALUES (10, 'tag:1', 'attr:10', 10.0)");
+
+ // check WAL
+ for (DataNodeWrapper dataNodeWrapper : EnvFactory.getEnv().getDataNodeWrapperList()) {
+ String walNodeDir = dataNodeWrapper.getWalDir() + File.separator + "0";
+ File[] walFiles = new File(walNodeDir).listFiles(f -> f.getName().endsWith(".wal"));
+ if (walFiles != null && walFiles.length > 0) {
+ File walFile = walFiles[0];
+ WALEntry entry;
+ try (WALReader walReader = new WALReader(walFile)) {
+ entry = walReader.next();
+ RelationalInsertTabletNode tabletNode = (RelationalInsertTabletNode) entry.getValue();
+ assertTrue(
+ Arrays.stream(tabletNode.getColumnCategories())
+ .noneMatch(c -> c == TsTableColumnCategory.ATTRIBUTE));
+
+ entry = walReader.next();
+ RelationalInsertRowsNode rowsNode = (RelationalInsertRowsNode) entry.getValue();
+ assertTrue(
+ Arrays.stream(rowsNode.getInsertRowNodeList().get(0).getColumnCategories())
+ .noneMatch(c -> c == TsTableColumnCategory.ATTRIBUTE));
+ return;
+ }
+ }
+ }
+ } finally {
+ EnvFactory.getEnv().cleanClusterEnvironment();
+ EnvFactory.getEnv().initClusterEnvironment();
+ }
+ }
}
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/schema/SchemaValidator.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/schema/SchemaValidator.java
index aaf5d08f43c..e2eafb53223 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/schema/SchemaValidator.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/schema/SchemaValidator.java
@@ -70,6 +70,7 @@ public class SchemaValidator {
insertStatement.validateTableSchema(metadata, context);
insertStatement.updateAfterSchemaValidation(context);
insertStatement.validateDeviceSchema(metadata, context);
+ insertStatement.removeAttributeColumns();
} catch (final QueryProcessException e) {
throw new SemanticException(e.getMessage());
}
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/sql/ast/WrappedInsertStatement.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/sql/ast/WrappedInsertStatement.java
index 43b09decdef..1cb351ec9f5 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/sql/ast/WrappedInsertStatement.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/sql/ast/WrappedInsertStatement.java
@@ -163,24 +163,49 @@ public abstract class WrappedInsertStatement extends WrappedStatement
tableSchema = null;
}
+ public static void processNonExistColumn(
+ ColumnSchema incoming, InsertBaseStatement innerTreeStatement, int i) {
+ // the column does not exist and auto-creation is disabled
+ SemanticException semanticException =
+ new SemanticException(
+ "Column " + incoming.getName() + " does not exists or fails to be " + "created",
+ TSStatusCode.COLUMN_NOT_EXISTS.getStatusCode());
+ if (incoming.getColumnCategory() != TsTableColumnCategory.FIELD
+ || !IoTDBDescriptor.getInstance().getConfig().isEnablePartialInsert()) {
+ // non-measurement columns cannot be partially inserted
+ throw semanticException;
+ } else {
+ // partial insertion
+ innerTreeStatement.markFailedMeasurement(i, semanticException);
+ }
+ }
+
+ public static void processTypeConflictColumn(
+ ColumnSchema incoming, ColumnSchema real, int i, InsertBaseStatement innerTreeStatement) {
+ SemanticException semanticException =
+ new SemanticException(
+ String.format(
+ "Incompatible data type of column %s: %s/%s",
+ incoming.getName(), incoming.getType(), real.getType()),
+ TSStatusCode.DATA_TYPE_MISMATCH.getStatusCode());
+ if (incoming.getColumnCategory() != TsTableColumnCategory.FIELD
+ || !IoTDBDescriptor.getInstance().getConfig().isEnablePartialInsert()) {
+ // non-measurement columns cannot be partially inserted
+ throw semanticException;
+ } else {
+ // partial insertion
+ innerTreeStatement.markFailedMeasurement(i, semanticException);
+ }
+ }
+
public static void validateTableSchema(
ColumnSchema incoming, ColumnSchema real, int i, InsertBaseStatement innerTreeStatement) {
if (real == null) {
- // the column does not exist and auto-creation is disabled
- SemanticException semanticException =
- new SemanticException(
- "Column " + incoming.getName() + " does not exists or fails to be " + "created",
- TSStatusCode.COLUMN_NOT_EXISTS.getStatusCode());
- if (incoming.getColumnCategory() != TsTableColumnCategory.FIELD
- || !IoTDBDescriptor.getInstance().getConfig().isEnablePartialInsert()) {
- // non-measurement columns cannot be partially inserted
- throw semanticException;
- } else {
- // partial insertion
- innerTreeStatement.markFailedMeasurement(i, semanticException);
- return;
- }
+ processNonExistColumn(incoming, innerTreeStatement, i);
+ return;
}
+
+ // check data type
if (incoming.getType() == null || incoming.getColumnCategory() != TsTableColumnCategory.FIELD) {
// sql insertion does not provide type
// the type is inferred and can be inconsistent with the existing one
@@ -188,22 +213,11 @@ public abstract class WrappedInsertStatement extends WrappedStatement
} else if (!InternalTypeManager.getTSDataType(real.getType())
.isCompatible(InternalTypeManager.getTSDataType(incoming.getType()))
&& !innerTreeStatement.isForceTypeConversion()) {
- SemanticException semanticException =
- new SemanticException(
- String.format(
- "Incompatible data type of column %s: %s/%s",
- incoming.getName(), incoming.getType(), real.getType()),
- TSStatusCode.DATA_TYPE_MISMATCH.getStatusCode());
- if (incoming.getColumnCategory() != TsTableColumnCategory.FIELD
- || !IoTDBDescriptor.getInstance().getConfig().isEnablePartialInsert()) {
- // non-measurement columns cannot be partially inserted
- throw semanticException;
- } else {
- // partial insertion
- innerTreeStatement.markFailedMeasurement(i, semanticException);
- return;
- }
+ processTypeConflictColumn(incoming, real, i, innerTreeStatement);
+ return;
}
+
+ // check column category
if (incoming.getColumnCategory() == null) {
// sql insertion does not provide category
innerTreeStatement.setColumnCategory(real.getColumnCategory(), i);
@@ -214,6 +228,8 @@ public abstract class WrappedInsertStatement extends WrappedStatement
incoming.getName(), incoming.getColumnCategory(), real.getColumnCategory()),
TSStatusCode.COLUMN_CATEGORY_MISMATCH.getStatusCode());
}
+
+ // construct measurement schema
TSDataType tsDataType = InternalTypeManager.getTSDataType(real.getType());
MeasurementSchema measurementSchema =
new MeasurementSchema(
@@ -244,4 +260,8 @@ public abstract class WrappedInsertStatement extends WrappedStatement
public void toLowerCase() {
getInnerTreeStatement().toLowerCase();
}
+
+ public void removeAttributeColumns() {
+ getInnerTreeStatement().removeAttributeColumns();
+ }
}
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertBaseStatement.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertBaseStatement.java
index 34b73b678fc..6e0a8bf0b2d 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertBaseStatement.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertBaseStatement.java
@@ -51,6 +51,7 @@ import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
+import java.util.Map.Entry;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;
@@ -368,6 +369,55 @@ public abstract class InsertBaseStatement extends Statement {
.collect(Collectors.toList());
}
+ @TableModel
+ public void removeAttributeColumns() {
+ if (columnCategories == null) {
+ return;
+ }
+
+ List<Integer> columnsToKeep = new ArrayList<>();
+ for (int i = 0; i < columnCategories.length; i++) {
+ if (!columnCategories[i].equals(TsTableColumnCategory.ATTRIBUTE)) {
+ columnsToKeep.add(i);
+ }
+ }
+
+ if (columnsToKeep.size() == columnCategories.length) {
+ return;
+ }
+
+ if (failedMeasurementIndex2Info != null) {
+ failedMeasurementIndex2Info =
+ failedMeasurementIndex2Info.entrySet().stream()
+ .collect(Collectors.toMap(e -> columnsToKeep.indexOf(e.getKey()), Entry::getValue));
+ }
+
+ if (measurementSchemas != null) {
+ measurementSchemas =
+ columnsToKeep.stream().map(i -> measurementSchemas[i]).toArray(MeasurementSchema[]::new);
+ }
+ if (measurements != null) {
+ measurements = columnsToKeep.stream().map(i -> measurements[i]).toArray(String[]::new);
+ }
+ if (dataTypes != null) {
+ dataTypes = columnsToKeep.stream().map(i -> dataTypes[i]).toArray(TSDataType[]::new);
+ }
+ if (columnCategories != null) {
+ columnCategories =
+ columnsToKeep.stream()
+ .map(i -> columnCategories[i])
+ .toArray(TsTableColumnCategory[]::new);
+ }
+
+ subRemoveAttributeColumns(columnsToKeep);
+
+ // to reconstruct indices
+ idColumnIndices = null;
+ attrColumnIndices = null;
+ }
+
+ protected abstract void subRemoveAttributeColumns(List<Integer> columnsToKeep);
+
public static class FailedMeasurementInfo {
protected String measurement;
protected TSDataType dataType;
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertMultiTabletsStatement.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertMultiTabletsStatement.java
index e103e6539c4..b4a1db885f8 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertMultiTabletsStatement.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertMultiTabletsStatement.java
@@ -31,6 +31,7 @@ import org.apache.tsfile.enums.TSDataType;
import org.apache.tsfile.exception.NotImplementedException;
import java.util.ArrayList;
+import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
@@ -172,4 +173,14 @@ public class InsertMultiTabletsStatement extends InsertBaseStatement {
}
return database;
}
+
+ @Override
+ public void removeAttributeColumns() {
+ subRemoveAttributeColumns(Collections.emptyList());
+ }
+
+ @Override
+ protected void subRemoveAttributeColumns(List<Integer> columnsToKeep) {
+ insertTabletStatementList.forEach(InsertBaseStatement::removeAttributeColumns);
+ }
}
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowStatement.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowStatement.java
index d33a83b0c32..ff0ccf310c8 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowStatement.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowStatement.java
@@ -526,4 +526,11 @@ public class InsertRowStatement extends InsertBaseStatement implements ISchemaVa
super.swapColumn(src, target);
CommonUtils.swapArray(values, src, target);
}
+
+ @Override
+ protected void subRemoveAttributeColumns(List<Integer> columnsToKeep) {
+ if (values != null) {
+ values = columnsToKeep.stream().map(i -> values[i]).toArray();
+ }
+ }
}
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowsOfOneDeviceStatement.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowsOfOneDeviceStatement.java
index 08630f82945..4dab9d423ce 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowsOfOneDeviceStatement.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowsOfOneDeviceStatement.java
@@ -195,4 +195,9 @@ public class InsertRowsOfOneDeviceStatement extends InsertBaseStatement {
}
return database;
}
+
+ @Override
+ protected void subRemoveAttributeColumns(List<Integer> columnsToKeep) {
+ insertRowStatementList.forEach(InsertRowStatement::removeAttributeColumns);
+ }
}
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowsStatement.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowsStatement.java
index 2d7ba7a2ba6..f0173885bdf 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowsStatement.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertRowsStatement.java
@@ -35,6 +35,7 @@ import org.apache.tsfile.exception.NotImplementedException;
import java.util.ArrayList;
import java.util.Arrays;
+import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
@@ -209,4 +210,14 @@ public class InsertRowsStatement extends InsertBaseStatement {
public Statement toRelationalStatement(MPPQueryContext context) {
return new InsertRows(this, context);
}
+
+ @Override
+ public void removeAttributeColumns() {
+ subRemoveAttributeColumns(Collections.emptyList());
+ }
+
+ @Override
+ protected void subRemoveAttributeColumns(List<Integer> columnsToKeep) {
+ insertRowStatementList.forEach(InsertBaseStatement::removeAttributeColumns);
+ }
}
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertTabletStatement.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertTabletStatement.java
index e6f6f5f1a20..84190176791 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertTabletStatement.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertTabletStatement.java
@@ -530,4 +530,14 @@ public class InsertTabletStatement extends InsertBaseStatement implements ISchem
}
return nullBitMaps[col].isMarked(row);
}
+
+ @Override
+ protected void subRemoveAttributeColumns(List<Integer> columnsToKeep) {
+ if (columns != null) {
+ columns = columnsToKeep.stream().map(i -> columns[i]).toArray();
+ }
+ if (nullBitMaps != null) {
+ nullBitMaps = columnsToKeep.stream().map(i -> nullBitMaps[i]).toArray(BitMap[]::new);
+ }
+ }
}
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/wal/io/WALReader.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/wal/io/WALReader.java
index 261e95eb52f..0c2e5a18c00 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/wal/io/WALReader.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/wal/io/WALReader.java
@@ -103,7 +103,7 @@ public class WALReader implements Closeable {
* @throws NoSuchElementException when not calling hasNext before.
*/
public WALEntry next() {
- if (nextEntry == null) {
+ if (!hasNext()) {
throw new NoSuchElementException();
}
WALEntry next = nextEntry;