[CALCITE-1044] Quirky handling of PrepareAndExecuteRequests maxRowCount attribute

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 1.5.0
• Component/s: avatica
• Assignee: Josh Elser
• Reporter: Carter Shanklin
• Created: 05/Jan/16 21:03
• Updated: 21/Jan/16 22:23
• Resolved: 13/Jan/16 03:35

Description

Another good find sent to me by cartershanklin.

He noticed when using the Protobuf wire API directly, provided a value of 0 for maxRowCount in a PrepareAndExecuteRequest resulted in no values being returned.

I dug around a little and found this little tweak done:

AvaticaStatement.java

  protected void executeInternal(String sql) throws SQLException {
    // reset previous state before moving forward.
    this.updateCount = -1;
    try {
      // In JDBC, maxRowCount = 0 means no limit; in prepare it means LIMIT 0
      final long maxRowCount1 = maxRowCount <= 0 ? -1 : maxRowCount;
      for (int i = 0; i < connection.maxRetriesPerExecute; i++) {
        try {
          Meta.ExecuteResult x =
              connection.prepareAndExecuteInternal(this, sql, maxRowCount1);

It would be nice to also do this correction on the server side to get this behavior since our wire API so closely matches the JDBC API.