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Difference between Database Stages

Posted: Mon Oct 05, 2009 12:05 am
by victordsouza
Hi All,

Can anyone let me know the differences between the following stages

1. Oracle Stage
2. ODBC Stage
3. Dynamic RDBMS Stage

Basically I need answers to these questions:

1. Differences between the Stages
2. How to decide which one to be used
3. In terms of performance which one is good(rate the 3)
3. If possible what is the mechanism involved in each of the stages
4. When using Oracle Enterprise stage there are always warnings of "Implicit conversion from source type". How to overcome this

Thanks

Posted: Mon Oct 05, 2009 4:17 am
by ray.wurlod
The Oracle Enterprise stage uses either direct read or SQL via the Oracle client interface (OCI) to retrieve data, and either the Oracle bulk loader (sqlldr) or SQL via the OCI to send data to an Oracle table. An ODBC stage uses an ODBC driver, ODBC protocols and ODBC API calls to retrieve or put data. The Dynamic RDBMS can use either of these methods or others (for other database types) depending upon the database chosen.

In general prefer the Oracle Enterprise stage in parallel jobs.

How long is a piece of string? Theoretically the Oracle Enterprise stage should out-perform the others, but how do you define "performance"?

To overcome alerts about implicit conversions prevent implicit conversions by getting the metadata in your job to match exactly what's being processed.

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