[FLINK-20378] Watermark generation check TIMESTAMP_WITHOUT_TIME_ZONE

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 1.11.1
• Component/s: Table SQL / Planner
• Assignee: Unassigned
• Reporter: wxmimperio
• Created: 26/Nov/20 11:44
• Updated: 30/Nov/20 03:09
• Resolved: 26/Nov/20 12:47

Description

 

 

 def generateWatermarkGenerator(
      config: TableConfig,
      inputType: RowType,
      watermarkExpr: RexNode): GeneratedWatermarkGenerator = {
    // validation
    val watermarkOutputType = FlinkTypeFactory.toLogicalType(watermarkExpr.getType)
    if (watermarkOutputType.getTypeRoot != LogicalTypeRoot.TIMESTAMP_WITHOUT_TIME_ZONE) {
      throw new CodeGenException(
        "WatermarkGenerator only accepts output data type of TIMESTAMP," +
          " but is " + watermarkOutputType)
    }

 

Why does watermark generation need to be detected as TIMESTAMP_WITHOUT_TIME_ZONE?

If I remove this check, what effect will it have on the watermark?