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Posted to issues@flink.apache.org by GitBox <gi...@apache.org> on 2022/07/07 06:20:55 UTC
[GitHub] [flink-table-store] JingsongLi commented on a diff in pull request #202: [FLINK-28110] Support projection pushdown for Hive readers
JingsongLi commented on code in PR #202:
URL: https://github.com/apache/flink-table-store/pull/202#discussion_r915498253
##########
flink-table-store-hive/flink-table-store-hive-connector/src/main/java/org/apache/flink/table/store/mapred/TableStoreRecordReader.java:
##########
@@ -36,24 +41,44 @@ public class TableStoreRecordReader implements RecordReader<Void, RowDataContain
private final RecordReaderIterator<RowData> iterator;
private final long splitLength;
+ @Nullable private final ProjectedRowData reusedProjectedRow;
+
private float progress;
public TableStoreRecordReader(
- org.apache.flink.table.store.file.utils.RecordReader<RowData> wrapped,
- long splitLength) {
- this.iterator = new RecordReaderIterator<>(wrapped);
- this.splitLength = splitLength;
+ TableRead read,
+ TableStoreInputSplit split,
+ List<String> columnNames,
+ List<String> selectedColumns)
Review Comment:
Add documentation here: Still output the original schema of the Row, the role of `selectedColumns` is to read out the required fields, other fields to fill Nulls.
##########
flink-table-store-hive/flink-table-store-hive-connector/src/main/java/org/apache/flink/table/store/mapred/TableStoreRecordReader.java:
##########
@@ -36,24 +41,44 @@ public class TableStoreRecordReader implements RecordReader<Void, RowDataContain
private final RecordReaderIterator<RowData> iterator;
private final long splitLength;
+ @Nullable private final ProjectedRowData reusedProjectedRow;
+
private float progress;
public TableStoreRecordReader(
- org.apache.flink.table.store.file.utils.RecordReader<RowData> wrapped,
- long splitLength) {
- this.iterator = new RecordReaderIterator<>(wrapped);
- this.splitLength = splitLength;
+ TableRead read,
+ TableStoreInputSplit split,
+ List<String> columnNames,
+ List<String> selectedColumns)
+ throws IOException {
+ if (columnNames.equals(selectedColumns)) {
+ reusedProjectedRow = null;
+ } else {
+ read.withProjection(selectedColumns.stream().mapToInt(columnNames::indexOf).toArray());
+ reusedProjectedRow =
+ ProjectedRowData.from(
+ columnNames.stream().mapToInt(selectedColumns::indexOf).toArray());
+ }
+
+ this.iterator = new RecordReaderIterator<>(read.createReader(split.split()));
+ this.splitLength = split.getLength();
this.progress = 0;
}
@Override
public boolean next(Void key, RowDataContainer value) throws IOException {
RowData rowData = iterator.next();
+
if (rowData == null) {
progress = 1;
return false;
} else {
- value.set(rowData);
+ if (reusedProjectedRow != null) {
+ reusedProjectedRow.replaceRow(rowData);
+ value.set(reusedProjectedRow);
Review Comment:
`value.set(reusedProjectedRow.replaceRow(rowData));`
--
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