Uploaded image for project: 'Apache Drill'
  1. Apache Drill
  2. DRILL-2723

Inaccurate row count estimate for text files results in BroadcastExchange

    XMLWordPrintableJSON

    Details

      Description

      The current method for estimating row count in text files is to divide the size of the file in bytes by 1024. This row count estimate is used by optimizer to decide if BroadcastExchange should be used.

      This results in massive memory consumption when using BroadCast exchange on a large table.

      We need a better way of estimating row count, or use a different metric when deciding to use BroadcastExchange.

        Attachments

          Activity

            People

            • Assignee:
              jnadeau Jacques Nadeau
              Reporter:
              sphillips Steven Phillips
            • Votes:
              0 Vote for this issue
              Watchers:
              2 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved: