database design – What is the "online" in OLAP and OLTP?

I am a little confused because I question the definition of the term "online" in OLTP and OLAP. I had the habit of thinking that the internet here means that we want our response in a limited time and based on the data available at a given time.

But OLAP queries can take a few hours to compute – is not it offline?

And a quick search indicates an offline OLAP that looks pretty confusing (online offline analytics processing) …?

What exactly is online?

SQL – Error Processing OLAP Cube in SSDT 2010

When I try to process the cube with the data source that I defined earlier, the following error is generated:

Processing information can not be provided.


FURTHER INFORMATION:

Method not found: Microsoft.DataWarehouse.Design.IEnvironmentService.get_IsAppMetroOrGreater () Boolean. (Microsoft.AnalysisServices.ManagementDialogs)

I've already changed the server name of the project properties and it still does not work.

data – Dictionary encoding for OLAP

Let's say we have a generic array as below:

identifier, name, price, quantity
20 product_x 5,00 100
20 product_y 5,00 100
20 product_z 5.00 100 100
20 product_a 5,00 100

For the name field, we probably have repetitive string variables. Doing groupings and comparisons on particularly large data sets with repetitive strings like this one would seem to be cheaper if all names were dictionary-encoded in an int16, for example. If that was the case, this practice would be common, but it is not. What are the reasons for this? What do I miss