Oracle FAQ Your Portal to the Oracle Knowledge Grid

Home -> Community -> Mailing Lists -> Oracle-L -> Re: Generic Connectivity

Re: Generic Connectivity

From: Michael Thomas <>
Date: Wed, 23 Jun 2004 05:48:08 -0700 (PDT)
Message-ID: <>


Quick list I've experienced with GC:

  1. Hung connections (across DB link) cause cursors to be leaked, eventually exceeding cursor limits.
  2. Generic does not handle 'every' ODBC syntax and the errors are not graceful. Some syntax errors can hang the Oracle GC server processes.
  3. Each DB link must be configured separately, requiring DB bounce. The configurations are complex. So if you need to add/drop connections frequently it requires some major work.
  4. The GC DB links were not robust if the target DB was unavailable. Things that hung on the DB links tended to require DB bounce to recover use of the DB link. Using trial and error (CTD) I was able to discover new ways to use DBMS_SESSION to flush db link connections and 'somewhat' recover things. Least fun part.
  5. Sybase ASA target DB table and column names are not all caps, requiring unique Oracle quoting "TargetTable" in SQL syntax. My target DB was Sybase Adaptive Server Anywhere (ASA 6.0).
  6. Required (UNIX/LINUX) ODBC configurations and technology that was difficult to assemble, and in some cases cost $$$. Data Direct and Sybase Support were our saviours.

Summary, its not easy to setup and maintain GC to every type of target database. But, the price is right. :-)

This is one of those features its nice to experiment and learn about first, just to understand the pain. Once its working, it was rewarding to see Sybase data in real-time via Oracle.

An alternative might be to use an ETL tool and pump major portions of data on a schedule into Oracle.

HTH Regards,

Mike Thomas

Do you Yahoo!?
Yahoo! Mail - 50x more storage than other providers!

Please see the official ORACLE-L FAQ:

To unsubscribe send email to: put 'unsubscribe' in the subject line.
Archives are at
FAQ is at
Received on Wed Jun 23 2004 - 07:44:51 CDT

Original text of this message