user: Question: Name the number of processors for October 2006 - January 2010
Columns: ['Model - Computer name', 'CPU type', 'No. of processors', 'Period of operation', 'Maximum peak performance ( Teraflops )', 'Use']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Cray XT4 - La Dôle', 'AMD Opteron quad-core Barcelona 2.3GHz', '160 (640 cores )', 'May 2007 - June 2012', '5.88', 'Numerical weather prediction ( MeteoSwiss )']
SQL:

assistant: SELECT "No. of processors" FROM "Table" WHERE "Period of operation" = 'October 2006 - January 2010';