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[HUDI-313] Fix select count star error when querying a realtime table

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This commit is contained in:
Wenning Ding
2019-10-23 13:53:57 -07:00
committed by n3nash
parent eda472adb0
commit 3251d62bd3
1 changed files with 17 additions and 0 deletions
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17
hudi-hadoop-mr/src/main/java/org/apache/hudi/hadoop/realtime/HoodieParquetRealtimeInputFormat.java
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@@ -197,10 +197,27 @@ public class HoodieParquetRealtimeInputFormat extends HoodieParquetInputFormat i
return configuration;
}
/**
* Hive will append read columns' ids to old columns' ids during getRecordReader. In some cases, e.g. SELECT COUNT(*),
* the read columns' id is an empty string and Hive will combine it with Hoodie required projection ids and becomes
* e.g. ",2,0,3" and will cause an error. This method is used to avoid this situation.
*/
private static synchronized Configuration cleanProjectionColumnIds(Configuration conf) {
String columnIds = conf.get(ColumnProjectionUtils.READ_COLUMN_IDS_CONF_STR);
if (!columnIds.isEmpty() && columnIds.charAt(0) == ',') {
conf.set(ColumnProjectionUtils.READ_COLUMN_IDS_CONF_STR, columnIds.substring(1));
if (LOG.isDebugEnabled()) {
LOG.debug("The projection Ids: {" + columnIds + "} start with ','. First comma is removed");
}
}
return conf;
}
@Override
public RecordReader<NullWritable, ArrayWritable> getRecordReader(final InputSplit split, final JobConf job,
final Reporter reporter) throws IOException {
this.conf = cleanProjectionColumnIds(job);
LOG.info("Before adding Hoodie columns, Projections :" + job.get(ColumnProjectionUtils.READ_COLUMN_NAMES_CONF_STR)
+ ", Ids :" + job.get(ColumnProjectionUtils.READ_COLUMN_IDS_CONF_STR));