After creating cube in Transformer you place on Cognos 8 as a data source, to allow everyone to access it.
But since the reading process of Cognos 8Bi opens mdc cube file on file level, it locks and the problem of updates arises. No way to update a cube while it’s locked.
There are two ways to solve this problem:
1 Explicitly end Cognos 8 BI connection to this cube by shutting down Cognos 8 server. (a bad-bad-bad way — don’t do this in production, you’ll spoil reputation and it never recovers).
2 Redirect all queries to another cube (thereby locking it) and update target cube.
2nd variant is preferable and there’s a tool to do it — swapcubes.bat utility from Cognos.
So the algorithm should look like:
1 Making a copy of the target cube (_swap postfix is nice)
2 Running swap_cubes.bat to redirect data source to _swap.mdc. There’s a catch there, you need to supply dispatchername as a parameter, yet that’s not the dispatcher name from Cognos Configuration, but the output of “ping dispatchername” (not always the same network address, caused me some trouble)
3 Waiting some time for all connections to switch to new cube. Another problem of deciding a wait period. 15 min works for me.
4 Rebuilding\Updating the target cube.
5 Swapping data source back.