On 12/18/11 6:50 AM, ehaerim wrote:

> Two possible structures.
>
> [1] (Symbol, Date, Blob) => Symbol primary and Date is secondary key
> [2] (Symbol_Date, Blob) => Symbol_Date is single primary key

Relational databases nearly always work best when each individual data
item (column) is stored separately and is, therefore, individually
addressable. Combining values into compound values should only be done
when there is a specific reason to do it. Your scenario is well within
the design and implementation goals of all current RDBMS systems, so
there is no good reason to combine any table columns.

It will require extra work on your part and on the server's part to
process the compound items. Why do it?

Go with [2].