Hi Guys,

I am trying to decide which concept is better. I am building a database of Stock market historical data in MS Access.

In the attached file you can find 2 concepts I am considering (V1, V2).

Version1:

pro - flexibility. If I want to add new property I just add it into the table TBL_Value_Type_V1

contra - more difficult queries, more records in the TBL_Values (8000000 and more)

Version2:
pro - simple queries, less records

contra - when I want to add new value type I have to add new column into the table TBL_Values_V2. This makes is it less flexible. In addition I will have a lot of blanks in the database, since not all instruments have the same properties (for example Instr3 does not have open value)

Could you please advise which one is more common for the data structure I am working with? Any new ideas are welcome.

THANKS!!!

Are you using all of the columns as your primary key?