Which Compression ratio has a (none) DX 10 Name and a FOURCC of dxt4?
CREATE TABLE "s3_tc_format_comparison" (
  "fourcc" text,
  "dx_10_name" text,
  "description" text,
  "alpha_premultiplied" text,
  "compression_ratio" text,
  "texture_type" text
);
SELECT "compression_ratio" FROM "s3_tc_format_comparison" WHERE "dx_10_name"='(none)' AND "fourcc"='dxt4';