One column key or multiple column key?
<p>Suppose I have two tables in an RDBMS that try to model storage and retrieval of same data based on different key specification.  Table1 stores the entire key in a single char column, Table2 stores the key in multiple columns, like so:</p>

<p>Table1: key=String, value=Data</p>

<p>Table2: col1=String, col2=String, value=Data</p>

<p>Table1 key holds the same information as the combination of col1 and col2, plus potentially delimiters, ex. key="NASDAQ/SUNW", col1="NASDAQ", col2="SUNW"</p>

<p>I am interested in efficient data retrieval.  Would using Table1 be more efficient than Table2?</p>