[HUDI-8783] Add tests for decimal data type

[linliu-code]

Change Logs

Add a test to insert/update/delete/read data for a MOR table

Impact

Verify that decimal data type workflow works.

Risk level (write none, low medium or high below)

Low.

Documentation Update

Describe any necessary documentation update if there is any new feature, config, or user-facing change. If not, put "none".

• The config description must be updated if new configs are added or the default value of the configs are changed
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Contributor's checklist

• Read through contributor's guide
• Change Logs and Impact were stated clearly
• Adequate tests were added if applicable
• CI passed

[the-other-tim-brown]

Can you add various precisions so we can test the different possible representations in parquet?
https://github.com/apache/parquet-format/blob/master/LogicalTypes.md#decimal

[linliu-code]

sg

[danny0405]

yeah, let's test at least 3 cases:

1. precision <= 10
2. precision > 10 && precision < 18
3. precision > 18

[linliu-code]

I already did.

[linliu-code]

@ParameterizedTest @CsvSource(value = Array("10,2", "20,10", "38,18", "5,0"))
So, let me add one more (15, 10)

[linliu-code]

Now:
@ParameterizedTest @CsvSource(value = Array("10,2", "15,5", "20,10", "38,18", "5,0"))

[danny0405]

I see a special handling for Spark decimal data type for precision < 18 in the UnsafeRow decimal getter:

public Decimal getDecimal(int ordinal, int precision, int scale) {
    if (isNullAt(ordinal)) {
      return null;
    }
    if (precision <= Decimal.MAX_LONG_DIGITS()) {
      return Decimal.createUnsafe(getLong(ordinal), precision, scale);
    } else {
      byte[] bytes = getBinary(ordinal);
      BigInteger bigInteger = new BigInteger(bytes);
      BigDecimal javaDecimal = new BigDecimal(bigInteger, scale);
      return Decimal.apply(javaDecimal, precision, scale);
    }
  }

Should we do it here too?

[linliu-code]

Ok. let me add it here.

[linliu-code]

@danny0405 , I tried to cast it, but I think we so far we have lost the precision and scale information from FIXED type here. So we can not do the special treatment.

[hudi-bot]

CI report:

• 77e9370 Azure: SUCCESS

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