mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-17 21:24:28 +00:00
23 lines
733 B
SQL
23 lines
733 B
SQL
-- max_memory_usage = 10000000000 (10 GB default)
|
|
-- Intel® Xeon® E5-1650 v3 Hexadcore 128 GB DDR4 ECC
|
|
-- Estimated time: ~ 250 seconds
|
|
-- Read rows: ~ 272 000 000
|
|
SELECT
|
|
key,
|
|
uniqState(uuid_1) uuid_1_st,
|
|
uniqState(uuid_2) uuid_2_st,
|
|
uniqState(uuid_3) uuid_3_st
|
|
FROM (
|
|
SELECT
|
|
rand64() value,
|
|
toString(value) value_str,
|
|
UUIDNumToString(toFixedString(substring(value_str, 1, 16), 16)) uuid_1, -- Any UUID
|
|
UUIDNumToString(toFixedString(substring(value_str, 2, 16), 16)) uuid_2, -- More memory
|
|
UUIDNumToString(toFixedString(substring(value_str, 3, 16), 16)) uuid_3, -- And more memory
|
|
modulo(value, 5000000) key -- Cardinality in my case
|
|
FROM numbers(550000000)
|
|
)
|
|
GROUP BY
|
|
key
|
|
LIMIT 100;
|