Kbase P101079: Concatenating a LONGCHAR with a CHAR is slow
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
10/08/2006 |
|
Status: Verified
FACT(s) (Environment):
OpenEdge 10.x
SYMPTOM(s):
Concatenating a LONGCHAR with a CHAR is slow
Concatenating a LONGCHAR with a CHAR is slower than concatenating a CHAR to a CHAR.
Performance issue when combining LONGCHAR with character variable
CAUSE:
This is expected behavior. When you write :
v_LONGCHAR = v_LONGCHAR + v_CHAR .
you implicitly ask Progress to cast v_CHAR to a LONGCHAR dataType. This operation is resource consuming.
FIX:
If you have loop in which you concatenate a CHAR to a LONGCHAR in each iteration you can implement a solution that use a bridge CHAR buffer variable. A sample:
Original code:
DEFINE VARIABLE v_LONGCHAR AS LONGCHAR NO-UNDO.
DEFINE VARIABLE v_CHAR AS CHARACTER NO-UNDO.
DEFINE VARIABLE i AS INTEGER NO-UNDO.
ETIME(YES).
DO i = 1 TO 100000:
v_char = CHR(i MODULO 250).
v_LONGCHAR = v_LONGCHAR + v_CHAR.
END.
MESSAGE ETIME
VIEW-AS ALERT-BOX INFO BUTTONS OK.
Modified code:
DEFINE VARIABLE v_LONGCHAR AS LONGCHAR NO-UNDO.
DEFINE VARIABLE v_CHAR AS CHARACTER NO-UNDO.
DEFINE VARIABLE i AS INTEGER NO-UNDO.
ETIME(YES).
DO i = 1 TO 100000:
v_char = CHR(i MODULO 250).
IF LENGTH(tempCharBuffer) + LENGTH(v_Char) > 31000 THEN DO:
v_LONGCHAR = v_LONGCHAR + tempCharBuffer.
v_LONGCHAR = v_LONGCHAR + v_CHAR.
tempCharBuffer = "".
END.
ELSE
tempCharBuffer = tempCharBuffer + v_CHAR.
END.
v_LONGCHAR = v_LONGCHAR + tempCharBuffer.
tempCharBuffer = "".
MESSAGE ETIME
VIEW-AS ALERT-BOX INFO BUTTONS OK.