External Data Sources - Problems refreshing data

[Ahchay]

Hi all, having a bit of trouble getting the External Data Source to work as expected under Cognos 10 (10.1.1 to be exact)

The problem we're seeing is that Cognos never actually appears to refresh the data source when the contents of the file are updated.

Steps:

1. A simple CSV (for testing purposes) containing the following:

Cognos10.csv
BRAND,TARGET
CRY,1000
THO,1020

2. Open Report Studio with my framework package as normal, and click on Manage External Data (green database icon) - browse to Cognos10.csv, select "Allow the server to automatically load the file", give it a namespace name (in this case, keeping the default) and click through the wizard to associate BRAND with an item in my package ([Bookings].[Brand Code], not that it matters) - default mapping options, summaries etc. Publish as a new framework.

3. Create a simple list item containing the new items and the report shows as follows (as expected):

BRAND	TARGET
CRY	1000
THO	1020

4. Now, if I then edit the CSV file to add a third brand ('FIN' for the sake of argument) like so:

Cognos10.csv
BRAND,TARGET
CRY,1000
THO,1020
FIN,800

... and then try and refresh the report... Nothing. Data stays exactly as it was, unless and until I open the report in design mode and re-establish the link.

What am I doing wrong? Have tried the following:

- File stored locally and on UNC network share ((\\SERVER\Share\File.csv)
- Leaving it overnight and refreshing on following day
- Logging out completely, and then retrying
- Changing "Use Local Cache" property on the query.

We've been told by our IBM pre-sales team (Yeah, I know) that this should work, and the documentation seems to back them up on this, so what am I missing?

[Ahchay]

Hmmm. May have answered my own question here...

If I set the file path to a UNC path *and* force a log out/login then the data refreshes - Still not sure what happens if the report is scheduled to run, so will be trying that next.

[Lynn]

I had problems using external data in batch mode. Never found a solution. There are other threads about this on the site but I don't recall anyone posting that they've gotten it to work.

[Ahchay]

Yeah, we've been experimenting with it a bit - it's one of the key things that people prefer about Business Objects, and it doesn't really feel fit for a production environment yet.

The "Allow server to update" checkbox does seem to work - within certain limits:

- The file has to be accessible to both the report writer and the Cognos service using the same path name - i.e. S:\Data\file.csv will work in Report Studio but will not be refreshable by Cognos, but \\Server\Shared\Data\file.csv will - also stuff in My Documents etc won't be accessible by the service. This also means that if a file is loaded as C:\Data.csv (or whatever) and that file happens to be available from both locations, then it will work, but it may not load the file that the report writer thinks it should.

- The file won't be reloaded within a single 'session' - for interactive user sessions this means that users have to log out and then back in again in order to pick up any changes (so, no use for frequently updated files really), but scheduled reports do seem to create a new session for each execution and, therefore, do pick up changes

Struggling now with file size limits.