15G
CREATE TABLE t (x UInt64, d32 Decimal32(3), d64 Decimal64(4), d128 Decimal128(5)) ENGINE = Memory
INSERT INTO t SELECT number AS x, x % 1000000 AS d32, x AS d64, x d128 FROM numbers_mt(200000000) SETTINGS max_threads = 8
DROP TABLE IF EXISTS t
SELECT toUInt32(x) y, toDecimal32(y, 1), toDecimal64(y, 5), toDecimal128(y, 6) FROM t FORMAT Null
SELECT toInt32(x) y, toDecimal32(y, 1), toDecimal64(y, 5), toDecimal128(y, 6) FROM t FORMAT Null
SELECT toInt64(x) y, toDecimal32(y, 1), toDecimal64(y, 5), toDecimal128(y, 6) FROM t FORMAT Null
SELECT toUInt64(x) y, toDecimal32(y, 1), toDecimal64(y, 5), toDecimal128(y, 6) FROM t FORMAT Null
SELECT toInt128(x) y, toDecimal32(y, 1), toDecimal64(y, 5), toDecimal128(y, 6) FROM t FORMAT Null
SELECT toInt256(x) y, toDecimal32(y, 1), toDecimal64(y, 5), toDecimal128(y, 6) FROM t LIMIT 10000000 FORMAT Null
SELECT toUInt256(x) y, toDecimal32(y, 1), toDecimal64(y, 5), toDecimal128(y, 6) FROM t LIMIT 10000000 FORMAT Null
SELECT toFloat32(x) y, toDecimal32(y, 1), toDecimal64(y, 5), toDecimal128(y, 6) FROM t FORMAT Null
SELECT toFloat64(x) y, toDecimal32(y, 1), toDecimal64(y, 5), toDecimal128(y, 6) FROM t FORMAT Null
SELECT toInt32(d32), toInt64(d32), toInt128(d32) FROM t FORMAT Null
SELECT toInt32(d64), toInt64(d64), toInt128(d64) FROM t FORMAT Null
SELECT toInt32(d128), toInt64(d128), toInt128(d128) FROM t FORMAT Null
SELECT toFloat32(d32), toFloat32(d64), toFloat32(d128) FROM t FORMAT Null
SELECT toFloat64(d32), toFloat64(d64), toFloat64(d128) FROM t FORMAT Null
SELECT toInt256(d32), toInt256(d64), toInt256(d128) FROM t FORMAT Null