user: Question: What is the oldest year that the Royal Philharmonic Orchestra released a record with Decca Records?
Columns: ['Cellist', 'Orchestra', 'Conductor', 'Record Company', 'Year of Recording', 'Format']
Types: ['text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Mstislav Rostropovich', 'Royal Philharmonic Orchestra', 'Sir Malcolm Sargent', 'EMI', 1957.0, 'CD']
SQL:

assistant: SELECT MIN("Year of Recording") FROM "Table" WHERE "Orchestra" = 'Royal Philharmonic Orchestra' AND "Record Company" = 'Decca Records';