Where has all the spending gone?
Where have all the yuan gone?
Where have all the treasuries gone?
How can this be correlated with SQL? First, data availability is determined by the SELECT statement. You query the database to determine if data that meets search criteria exists. Second, data compatibility is determined by the INSERT statement. Data is accepted if it is within the database structure’s definition. Third, data reliability is determined by the UPDATE statement. Data has to change as the database’s state changes to continue to meet the database’s objectives. Finally, data economy is determined by the DELETE statement. Data that is no longer of use can be removed from the database to free up available resources to achieve cost effectiveness.
Christensen’s Innovator’s Dilemma tetrad has provided us with another viewpoint on the SQL tetrad.