NULL determination / handling
Posted: Thu Aug 20, 2009 1:35 pm
This started in a previous post :
APT_CombinedOperatorController,0: Null string argument.
I think my current question, though related, is deviating from the original question so I started a new topic.
Me : "(an EMPTY string; I guess this differs from a NULL string)"
chulett : It most definitely does. Differ, that is.
Most of the time I am dealing with sequential or CFFs being loaded into and RDBMS (with some sort of transform or modification in between, oterwise I would just be perfoming bulk loads).
The data is either delimited or fixed length, but a NULL string is usually indicated via 2 delimiters with nothing between. Does Datastage set a null indicator for this or treat this as an empty string?
First I should ask if DataStage is maintaining a null-indicator for each nullable column like the RDBMSs do? If so, when NOT reading from an RDBMS, how does one set this indicator? Derive the column to @NULL or @NULL.str ? And then does IsNull query this indicator without looking at the content of the field?
APT_CombinedOperatorController,0: Null string argument.
I think my current question, though related, is deviating from the original question so I started a new topic.
Me : "(an EMPTY string; I guess this differs from a NULL string)"
chulett : It most definitely does. Differ, that is.
Most of the time I am dealing with sequential or CFFs being loaded into and RDBMS (with some sort of transform or modification in between, oterwise I would just be perfoming bulk loads).
The data is either delimited or fixed length, but a NULL string is usually indicated via 2 delimiters with nothing between. Does Datastage set a null indicator for this or treat this as an empty string?
First I should ask if DataStage is maintaining a null-indicator for each nullable column like the RDBMSs do? If so, when NOT reading from an RDBMS, how does one set this indicator? Derive the column to @NULL or @NULL.str ? And then does IsNull query this indicator without looking at the content of the field?