modifications due to cascade update in a relationship 1

[Ashank4vba]

Hi,

Can you please confirm this?
2 Tables have a relationship set between them on one field say 'ID'. The relationship has 'referential integrity' setting checked already - but not its sub settings (you know, the cascade updates and deletes).
Now I need to update the 'ID' field values in the database. In order to make things simpler, I thought I would set the 'cascading updates' setting checked in the relationship so that when I change the values in the primary table, the values are automatically cascaded back to the related table.
Now, I want to know if any 'unwanted' or 'unexpected' changes might happen just by checking the 'cascade updates' option (i.e., even before I start doing the updates)???
Please confirm. Thanks a lot in advance.

 

[willir]

Ashank4vba

Personally, I avoid using cascading updates and never use cascading deletes -- just a personal thing; there are others who do use this feature.

It sounds like you have a good reason to use Cascading updates. Make sure you back up your database, and I suggest you have exclusive access to the database so as not to have others locking records and such during the update.

Depending on the number of records involved, I suspect Access will use a lot of "overhead" for this task. I suspect it would be wise to use a PC with lots memory and lots of disk space for temp file. Access will probably try to load the entire table or tables into memory, but may have to write the work files to disk.

If you have your database split into a front end / back end, you may wish to do the update on the backend database rather than working with linked tables.

If your database is on the network, processing may be more effecient if you copy the data table locally, and work on the local database and then copy it back to the network.

Afterwards, run "Compact and Repair" to a) free up space and b) check the integrity of the data.

A useful tool to create a query or two that runs through the affected data -- perhaps a Sum and Count check on number of records and the total value of a number field. Run the query(ies) before and after and verify the number match.

Did I mention to backup your database?

Richard