×
INTELLIGENT WORK FORUMS
FOR COMPUTER PROFESSIONALS

Log In

Come Join Us!

Are you a
Computer / IT professional?
Join Tek-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Tek-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Same table in source and target

Same table in source and target

Same table in source and target

(OP)
Well I'm back again =D

So I have a conceptual question...

I've been given a source and target for a mapping that involve the same table.  The source is actually a view made up of columns from two tables, one of which is also my target table.

My question is regarding whether there's any danger to loading a table that is both the target and a part of the source?  My worry is coordination between the reads and writes of that table.

The target table is a type 2 slowly changing dimension.  All tables are SQL Server.

Thanks

RE: Same table in source and target

We do it all the time, but not quite the way you're doing it. We use the source table and check for changes and apply them to the same table as the target. Shouldn't be a problem.

"I think we're all Bozos on this bus!" - Firesign Theatre jester

RE: Same table in source and target

(OP)
Hmm...maybe I'll try it then.  The view also contains the primary key from the target table.  Sometimes it's null because the row doesn't exist in the target table yet.  Perhaps I can use that as an easy indicator for an insert or update.

How are you checking for changes?  Via lookup against the target object?

RE: Same table in source and target

Standard documentation gives you the exact details on how to set up the mapping. Basically you cache the target to a lookup and perform an evaluation on all ports/fields.

Use a filter to avoid processing rows that are unchanged (which should be the vast majority with slowly changing dimensions)   

Ties Blom
 

RE: Same table in source and target

(OP)
Thanks, I'll give it a try.  The only exception looks like will be switching to a dynamic lookup as I may be confronted with a historical load of that table.

RE: Same table in source and target

Has anyone had the issue where not all of the available database tables show up for selection within the informatica tool?

thanks

RE: Same table in source and target

Usually a question of selecting the 'all' button.
The default setting is that a list is shown for those tables that are in the schema that matches the authorization id. Select 'all' and you see all objects listed.

Ties Blom
 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Tek-Tips Forums free from inappropriate posts.
The Tek-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Click Here to join Tek-Tips and talk with other members! Already a Member? Login

Close Box

Join Tek-Tips® Today!

Join your peers on the Internet's largest technical computer professional community.
It's easy to join and it's free.

Here's Why Members Love Tek-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close