[jira] [Created] (TAJO-1093) DateTimeFormat.to_char() is slower than SimpleDateFormat.format()

["Hyoungjun Kim (JIRA)" <ji...@apache.org>]

Hyoungjun Kim created TAJO-1093:
-----------------------------------

             Summary: DateTimeFormat.to_char() is slower than SimpleDateFormat.format()
                 Key: TAJO-1093
                 URL: https://issues.apache.org/jira/browse/TAJO-1093
             Project: Tajo
          Issue Type: Improvement
            Reporter: Hyoungjun Kim
            Priority: Minor


I tested DateTimeFormat class with the below code.
{code}
TimeMeta tm = new TimeMeta();
DateTimeUtil.toJulianTimeMeta(DateTimeUtil.javaTimeToJulianTime(System.currentTimeMillis()), tm);

int iteration = 1000000;
long startTime = System.currentTimeMillis();
for (int i = 0; i < iteration; i++) {
  DateTimeFormat.to_char(tm, "YYYY-MM-DD HH24:MI:SS");
}
long endTime = System.currentTimeMillis();
System.out.println("DateTimeFormat.to_char: " + (endTime - startTime) + " ms");

///////////////////////////////////////////////////////////
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date date = new Date();
startTime = System.currentTimeMillis();
for (int i = 0; i < iteration; i++) {
  df.format(date);
}
endTime = System.currentTimeMillis();
System.out.println("SimpleDateFormat.format: " + (endTime - startTime) + " ms");

///////////////////////////////////////////////////////////
startTime = System.currentTimeMillis();
for (int i = 0; i < iteration; i++) {
  DateTimeFormat.parseDateTime("2014-01-01 12:11:11", "YYYY-MM-DD HH24:MI:SS");
}
endTime = System.currentTimeMillis();
System.out.println("DateTimeFormat.parseDateTime: " + (endTime - startTime) + " ms");

///////////////////////////////////////////////////////////
startTime = System.currentTimeMillis();
for (int i = 0; i < iteration; i++) {
  df.parse("2014-01-01 12:11:11");
}
endTime = System.currentTimeMillis();
System.out.println("SimpleDateFormat.parse: " + (endTime - startTime) + " ms");
{code}

The following is the test result. DateTimeFormat.to_char is 20 times slower than SimpleDateFormat.format.

{noformat}
DateTimeFormat.to_char: 6993 ms
SimpleDateFormat.format: 373 ms
DateTimeFormat.parseDateTime: 798 ms
SimpleDateFormat.parse: 1400 ms
{noformat}



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