Re: Help about Sql Delete performance

[Justin Taylor <jtaylor.0ab@xxxxxxxxx>]

Have you ran it thru Visual Explain?



> date: Fri, 24 Jan 2025 12:59:26 +0100
> from: Marco Facchinetti <marco.facchinetti@xxxxxxxxx>
> subject: Help about Sql Delete performance
>
> Hi we are performing this Sql over a table without triggers, LF and
> journals:
>
> DELETE FROM TSEDAT4/MULTTT400F WHERE LGIDL1 <> ' ' AND LGIDL1 NOT IN(Select
> L1ID FROM TSEDAT4/MULTTT100F)
>
> The statement runs but I see in Wrkactjob opt. 14 that I/O and RRN almost
> the same numbers as if each record generate a single I/O. Since it's an Sql
> statement and not RPG files access I was expecting blocked I/O operations
> and thus better performances.
>
> Get Diagnostic resturns:
>
> COMMAND_FUNCTION_CODE=+43
> COMMAND_FUNCTION=EXECUTE IMMEDIATE
> CONDITION_NUMBER=+1
> DB2_MESSAGE_ID=SQL7955
> DB2_ORDINAL_TOKEN_1=MULTTT400F
> DB2_ORDINAL_TOKEN_2=TSEDAT4
> DB2_ORDINAL_TOKEN_3=38952036
> DB2_ORDINAL_TOKEN_4=0
> DB2_SQL_ATTR_CONCURRENCY=L
> DB2_SQL_ATTR_CURSOR_CAPABILITY=D
> DB2_SQL_ATTR_CURSOR_HOLD=N
> DB2_SQL_ATTR_CURSOR_ROWSET=N
> DB2_SQL_ATTR_CURSOR_SCROLLABLE=N
> DB2_SQL_ATTR_CURSOR_SENSITIVITY=S
> DB2_SQL_ATTR_CURSOR_TYPE=F
> DB2_SQLERRD_SET=Y
> DB2_SQLERRD3=+38952036
> DB2_SQLERRD6=-134613515
> DB2_TOKEN_COUNT=+4
> DB2_TOKEN_STRING=MULTTT400F TSEDAT4 38952036 0
> DYNAMIC_FUNCTION_CODE=+19
> DYNAMIC_FUNCTION=DELETE WHERE
> MESSAGE_TEXT=38952036 righe rilevate da MULTTT400F in TSEDAT4.
> MORE=N
> NUMBER=+1
> RETURNED_SQLSTATE=00000
> ROW_COUNT=+38952036
>
> Any hint?
>
> TIA
> --
> Marco Facchinetti
>
> Mr S.r.l.
>
> Tel. 035 962885
> Cel. 393 9620498
>
> Skype: facchinettimarco