importing ODBC

dr46014 · Post by **dr46014** » Mon Dec 18, 2006 9:12 pm

hi all
this is rather a more theoritical question than a practical one.when we import table defination as ODBC we specify the DSN,user name,password and table name.so the column defination is imported and stored in the repository.but there is an option to create the table in the database from DataStage interface.in such a case we specify the DDL and table is created.in that case no meta data is imported and stored in the repository.so how the engine works i could not understand.please guide me that is it mandatory to import everything before using that in the job??
we w dont import and manually specify the table definations what will be the problem.

kumar_s · Post by **kumar_s** » Mon Dec 18, 2006 9:15 pm

Its not mandate to import the Table definition for the job to process. By importing the table definition, you are storing a copy of the layout in the Datastage metadata repository. So you can re use it, and will ease your job to specify the metadata for a large tables.

ray.wurlod · Post by **ray.wurlod** » Mon Dec 18, 2006 9:19 pm

When you click the GetSQLInfo button, or when you click the Create DDL button, the ODBC stage interrogates the data source for its syntax rules. This means that the table definition created is syntactically legitimate (most of the time - some drivers report inaccurately).

Whenever you generate metadata, it is recommended best practice to click Save on the Columns grid to store the table definition into the Repository. Change the category from Saved\StageName to ODBC\DSN ideally during the Save dialog, and remember to visit the Repository to add a short description to the saved table definition, so as to make life easier for future developers and maintainers.

dr46014 · Post by **dr46014** » Mon Dec 18, 2006 9:21 pm

thank you for your response.
can you plz tell me in the table defination why a data element column and display column is there.what are the significance of those columns

dr46014 · Post by **dr46014** » Mon Dec 18, 2006 9:27 pm

i am new to this forum.
i am not able to read the whole post.a part of the post is getting truncated.
why is it so...........

chulett · Post by **chulett** » Mon Dec 18, 2006 9:40 pm

Because it is one of Ray's patented Premium Posts.

kumar_s · Post by **kumar_s** » Mon Dec 18, 2006 10:05 pm

If you are refering to Length and Display, Length is the actual length defined for that field, and Display is the length you specify for the datastage so show up the number of digit when you do view Data.

ray.wurlod · Post by **ray.wurlod** » Mon Dec 18, 2006 10:51 pm

Search for Data Element will reveal more. A Data Element is like a luggage tag for data; you can record, for example, that this ten digit number is a tax ID, whereas this ten digit number is a telephone number and yet another is a part number. In short, business metadata.

Let's say you have a data element called Money. Then Usage Analysis can quickly show all the jobs (and Transforms) that process money.

With tools like IBM WebSphere Business Glossary now in the mix, I predict that the use of Data Elements to map business metadata to technical metadata, and therefore more rigorously to define business rules (including silly-sounding ones like preventing BI tools from presenting average telephone numbers) will be on the increase.