David Mollitor created SPARK-59546:
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             Summary: Avoid per-row exceptions when inferring TimeType in JSON, 
CSV, and XM
                 Key: SPARK-59546
                 URL: https://issues.apache.org/jira/browse/SPARK-59546
             Project: Spark
          Issue Type: Improvement
          Components: SQL
    Affects Versions: 4.1.0
            Reporter: David Mollitor


h2. Summary

JSON, CSV, and XML schema inference probe whether a string value is a {{TIME}} 
by calling the throwing {{TimeFormatter.parse}} inside {{allCatch opt}}:

{code:scala}
if (isTimeTypeEnabled && (allCatch opt timeFormatter.parse(field)).isDefined) {
  TimeType(TimeType.DEFAULT_PRECISION)
}
{code}

For the default (pattern-less) formatter, {{parse}} calls 
{{SparkDateTimeUtils.stringToTimeAnsi}}, which throws a 
{{SparkDateTimeException}} (filling in a stack trace) for every value that is 
not a time. During inference of a non-time column, this is one 
thrown-and-caught exception per row.

This is the same cost that SPARK-39193 / SPARK-39280 / SPARK-39281 removed for 
timestamp and date inference by introducing a non-throwing {{parseOptional}} 
(that change reported exception handling as more than 90% of type-inference 
time). {{TimeType}} was added later and never got a {{parseOptional}}, so it is 
the only datetime formatter still using the throwing probe -- the timestamp 
probe immediately below the time probe already uses {{parseOptional}}.



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