PrimaryKey vs Idkey
Just wondering an Insight in the difference between these two indexes
IdKey / PrimaryKey
Property Identifier As %Integer
Index Index1 on Identifier [Idkey]
Index Index2 on Identifier [PrimaryKey]
What's the difference?
1. If I don't have Index1 and only have Index2, then cache does still make its own id.
So how and why do I ever use the PrimaryKey. In Joins ??
Table1.Identifier = Table2.Identifier instead of Table1.Id = Table2.id ??
But I can still use Table1.Id = Table2.Id as cache still made one ID field
So where is PrimaryKey useful in cache?
2. If I declare Index1 , I am not able to have any Bitmap indexes [Cache throws an error on compilation saying I have an Idkey index]