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NULL & Sequential File
Posted: Sat Oct 02, 2010 11:38 pm
by karthi_gana
All,
what is the relationship between NULL and a sequential file?
does sequential file allows NULL ? say for example, if i declared variables like below
eno int No (Allow Null)
age int Yes (Allow Null)
ename varchar(50) No (Allow Null)
I have designed a jpb like below
ODBC --> Transformer ---> Sequential file
assume age has some NULL values in the table.
emp table : 50 rows
age is not null - 45 rows
age is null - 5 rows
how many rows will be transferred to the sequential file? i didn't try this. Because this question just came to mind when i open this site from my home. i don't have datastage in my home pc. i can use datastage only from my office.
Posted: Sun Oct 03, 2010 6:04 am
by chulett
Sequential files allow nulls, yes. The Server product makes handling them a little easier, basically you'll end up with a empty string / field unless (of course) you are writing out to a fixed-width file. In that case you'll need to supply something of the appropriate size for the field, typically spaces.
Posted: Sun Oct 03, 2010 12:20 pm
by ray.wurlod
Technically, because there are no data types in a text file (only text), text files do NOT support NULL. Therefore your metadata need to describe how NULL is represented within the file/field.
Posted: Sun Oct 03, 2010 2:48 pm
by chulett
Technically. ![Wink :wink:](./images/smilies/icon_wink.gif)
Posted: Sun Oct 03, 2010 2:52 pm
by ray.wurlod
C'est moi.
![Cool 8)](./images/smilies/icon_cool.gif)
Posted: Mon Oct 04, 2010 11:54 pm
by karthi_gana
chulett wrote:Sequential files allow nulls, yes. The Server product makes handling them a little easier, basically you'll end up with a empty string / field unless (of course) you are writing out to a fixed-width file. In that case you'll need to supply something of the appropriate size for the field, typically spaces.
If i didn't supply something...what will happen?
Posted: Tue Oct 05, 2010 2:39 am
by ray.wurlod
Depends how your "default defaults" have been set up.
Posted: Tue Oct 05, 2010 2:45 am
by nani0907
It throws warnings in the job for sequential file to handle nulls...
Posted: Tue Oct 05, 2010 6:31 am
by chulett
In a Server job? PX, perhaps, but not Server.
Posted: Tue Oct 05, 2010 9:31 pm
by karthi_gana
"default defaults" ???
how to see or view it? where to see this value?
Posted: Tue Oct 05, 2010 11:01 pm
by ray.wurlod
[In parallel jobs only...]
There is a button on the Format properties called Defaults> (or something like that). This allows you to set the current format settings as default, replace the current with your most recently saved default, or to restore factory settings.
Posted: Wed Oct 06, 2010 9:43 pm
by karthi_gana
ray.wurlod wrote:[In parallel jobs only...]
There is a button on the Format properties called Defaults> (or something like that). This allows you to set the current format settings as default, replace the current with your most recently saved default, or to restore factory settings.
oh...ok.