How to Edit the Max Item Number
1. Abstract
The Entity ‘Max Item Number’ is used to reference data stored in a Cube version. It determines how the data pages are physically stored and influences performance as much as dataflow execution.
2. Context
The amount of master data will increase during an application lifetime, so having a review process of the Max Item Number will be critical. Since the Max Item Number is one of the parameters used by Board while assigning space to a Cube version, you can’t edit it straightforwardly all the time.
3. Content
When setting a Max Item Number, attention should be given to the potential growth rate over the application’s life, not simply the current number of items.
Changing the Max Item Number is a straightforward process if the Entity is not "in use," as in, there isn't an existing Board Cube version structured by that dimension.
Applying the Max Item Number change to an Entity used in at least one info Cube version requires it to be cleared. This consequently causes the data loss of all the info Cube versions structured by that Entity.
When Entities are used in a Cube structure, their Max Item Number is used by Board as a parameter to assign a dedicated amount of memory space to optimize compression and performance. This amount of space cant change once a Cube gets populated with data. For this reason, to edit a Max Item Number, all Cubes containing that dimension must be cleared to allow the assigned space to be reallocated.
NOTE: clearing the Entity is not necessary!
A very simple (yet safe) procedure to edit an Entity Max item Number that won’t require you to clear the Entity is to:
1. Request a service window* and activate the database in maintenance mode;
2. Execute a backup
3. Run an "Extract all Cubes" action
4. Run a clear all Cubes
5. Change the Max item No.
6. Open the summary tile and unload the database
7. Run the "Import all Cubes" action
8. Remove the maintenance mode
*only if the application is live and you are working in the production server.
Extract all Cubes and import all Cubes are standard Board actions that can be defined within a Board Procedure.
In case the Entity which requires a Max Item Number revision is used in just a few Cubes, instead of Clear & Reload all Cubes, it’s possible to Clear & Reload just those involving that dimensions through dedicated extracts and data readers.
Comments
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One additional comment: make sure that you are executing all the steps suggested with an admin profile without any security selections.
A common mistake is to run those steps with a security profile with the @user set up.
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