CREATE TABLE table_6315 ("Model" CLOB, "Codename" CLOB, "Capacities  ( GB ) " CLOB, "NAND type" CLOB, "Interface" CLOB, "Form factor" CLOB, "Controller" CLOB, "Seq. read/write MB/s" CLOB, "Rnd 4KB read/write IOPS  ( K ) " CLOB, "Introduced" CLOB)

Which interface uses Sandforce with a code name of Sierra Star?
SELECT "Interface" FROM table_6315 WHERE "Controller" = 'sandforce' AND "Codename" = 'sierra star'
SELECT "Interface" FROM "table_6315" WHERE "Codename" = 'sierra star' AND "Controller" = 'sandforce'