[CALCITE-3287] Union's getRowCount in RelMdRowCount has not consider 'union all'

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.22.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Unassigned
• Reporter: shenh062326
• Created: 23/Aug/19 07:47
• Updated: 06/Mar/20 04:36
• Resolved: 21/Sep/19 00:56

Description

when I read the RelMdRowCount.java, I found that union's getRowCount has not consider 'union all', while in Union.estimateRowCount has. I am not sure whether this is a bug, if it is, I can help fix it.

RelMdRowCount.java
public Double getRowCount(Union rel, RelMetadataQuery mq) {
    double rowCount = 0.0;
    for (RelNode input : rel.getInputs()) {
      Double partialRowCount = mq.getRowCount(input);
      if (partialRowCount == null) {
        return null;
      }
      rowCount += partialRowCount;
    }
    return rowCount;
  }

Union.java
  @Override public double estimateRowCount(RelMetadataQuery mq) {
    double dRows = RelMdUtil.getUnionAllRowCount(mq, this);
    if (!all) {
      dRows *= 0.5;
    }
    return dRows;
  }

Issue Links

• links to: GitHub Pull Request #1410