X

Welcome to All Things Warehouse Builder

  • ETL
    December 19, 2012

External table and preprocessor for loading LOBs

David Allan
Architect

I was using the COLUMN TRANSFORMS syntax to load LOBs into Oracle using the Oracle external which is a handy way of doing several stuff - from loading LOBs from the filesystem to having constants as fields. In OWB you can use unbound external tables to define an external table using your own arbitrary access parameters - I blogged a while back on this for doing preprocessing before it was added into OWB 11gR2.

For loading LOBs using the COLUMN TRANSFORMS syntax have a read through this post on loading CLOB, BLOB or any LOB, the files to load can be specified as a field that is a filename field, the content of this file will be the LOB data.

So using the example from the linked post, you can define the columns;

Then define the access parameters - if you go the unbound external table route you can can put whatever you want in here (your external table get out of jail free card);

This will let you read the LOB files fromn the filesystem and use the external table in a mapping.

Pushing the envelope a little further I then thought about marrying together the preprocessor with the COLUMN TRANSFORMS, this would have let me have a shell script for example as the preprocessor which listed the contents of a directory and let me read the files as LOBs via an external table. Unfortunately that doesn't quote work - there is now a bug/enhancement logged, so one day maybe. So I'm afraid my blog title was a little bit of a teaser....

Join the discussion

Comments ( 1 )
  • guest Tuesday, October 6, 2015

    You have mentioned using files, how to do the same for BLOB column in source table. For me it is failing with OWB using 11gR2 and 11.2.x OWB

    ORA-22992: cannot use LOB locators selected from remote tables



    ORA-00942: table or view does not exist



    ORA-00942: table or view does not exist



    ORA-00942: table or view does not exist


Please enter your name.Please provide a valid email address.Please enter a comment.CAPTCHA challenge response provided was incorrect. Please try again.Captcha