What the cores with a release date of February 2011 and a BGA-1023 socket?
CREATE TABLE "sandy_bridge_dual_core_32_nm" (
  "model_number" text,
  "s_spec_number" text,
  "cores" text,
  "frequency" text,
  "turbo" text,
  "l2_cache" text,
  "l3_cache" text,
  "gpu_model" text,
  "gpu_frequency" text,
  "socket" text,
  "i_o_bus" text,
  "release_date" text,
  "part_number_s" text,
  "release_price_usd" text
);
SELECT "cores" FROM "sandy_bridge_dual_core_32_nm" WHERE "socket"='bga-1023' AND "release_date"='february 2011';