Hash Functions | ClickHouse Docs

Hash functions can be used for the deterministic pseudo-random shuffling of elements.

Simhash is a hash function, which returns close hash values for close (similar) arguments.

Most hash functions accept any number of arguments of any types.

BLAKE3

Introduced in: v22.10.0

Calculates BLAKE3 hash string and returns the resulting set of bytes as FixedString. This cryptographic hash-function is integrated into ClickHouse with BLAKE3 Rust library. The function is rather fast and shows approximately two times faster performance compared to SHA-2, while generating hashes of the same length as SHA-256. It returns a BLAKE3 hash as a byte array with type FixedString(32).

Syntax

BLAKE3(message)

Arguments

message — The input string to hash. String

Returned value

Returns the 32-byte BLAKE3 hash of the input string as a fixed-length string. FixedString(32)

Examples

hash

SELECT hex(BLAKE3('ABC'))

┌─hex(BLAKE3('ABC'))───────────────────────────────────────────────┐
│ D1717274597CF0289694F75D96D444B992A096F1AFD8E7BBFA6EBB1D360FEDFC │
└──────────────────────────────────────────────────────────────────┘

MD4

Introduced in: v21.11.0

Calculates the MD4 hash of the given string.

Syntax

MD4(s)

Arguments

s — The input string to hash. String

Returned value

Returns the MD4 hash of the given input string as a fixed-length string. FixedString(16)

Examples

Usage example

SELECT HEX(MD4('abc'));

┌─HEX(MD4('abc'))──────────────────┐
│ A448017AAF21D8525FC10AE87AA6729D │
└──────────────────────────────────┘

MD5

Introduced in: v1.1.0

Calculates the MD5 hash of the given string.

Syntax

MD5(s)

Arguments

s — The input string to hash. String

Returned value

Returns the MD5 hash of the given input string as a fixed-length string. FixedString(16)

Examples

Usage example

SELECT HEX(MD5('abc'));

┌─HEX(MD5('abc'))──────────────────┐
│ 900150983CD24FB0D6963F7D28E17F72 │
└──────────────────────────────────┘

RIPEMD160

Introduced in: v24.10.0

Calculates the RIPEMD-160 hash of the given string.

Syntax

RIPEMD160(s)

Arguments

s — The input string to hash. String

Returned value

Returns the RIPEMD160 hash of the given input string as a fixed-length string. FixedString(20)

Examples

Usage example

SELECT HEX(RIPEMD160('The quick brown fox jumps over the lazy dog'));

┌─HEX(RIPEMD160('The quick brown fox jumps over the lazy dog'))─┐
│ 37F332F68DB77BD9D7EDD4969571AD671CF9DD3B                      │
└───────────────────────────────────────────────────────────────┘

SHA1

Introduced in: v1.1.0

Calculates the SHA1 hash of the given string.

Syntax

SHA1(s)

Arguments

s — The input string to hash String

Returned value

Returns the SHA1 hash of the given input string as a fixed-length string. FixedString(20)

Examples

Usage example

SELECT HEX(SHA1('abc'));

┌─HEX(SHA1('abc'))─────────────────────────┐
│ A9993E364706816ABA3E25717850C26C9CD0D89D │
└──────────────────────────────────────────┘

SHA224

Introduced in: v1.1.0

Calculates the SHA224 hash of the given string.

Syntax

SHA224(s)

Arguments

s — The input value to hash. String

Returned value

Returns the SHA224 hash of the given input string as a fixed-length string. FixedString(28)

Examples

Usage example

SELECT HEX(SHA224('abc'));

┌─HEX(SHA224('abc'))───────────────────────────────────────┐
│ 23097D223405D8228642A477BDA255B32AADBCE4BDA0B3F7E36C9DA7 │
└──────────────────────────────────────────────────────────┘

SHA256

Introduced in: v1.1.0

Calculates the SHA256 hash of the given string.

Syntax

SHA256(s)

Arguments

s — The input string to hash. String

Returned value

Returns the SHA256 hash of the given input string as a fixed-length string. FixedString(32)

Examples

Usage example

SELECT HEX(SHA256('abc'));

┌─HEX(SHA256('abc'))───────────────────────────────────────────────┐
│ BA7816BF8F01CFEA414140DE5DAE2223B00361A396177A9CB410FF61F20015AD │
└──────────────────────────────────────────────────────────────────┘

SHA384

Introduced in: v1.1.0

Calculates the SHA384 hash of the given string.

Syntax

SHA384(s)

Arguments

s — The input string to hash. String

Returned value

Returns the SHA384 hash of the given input string as a fixed-length string. FixedString(48)

Examples

Usage example

SELECT HEX(SHA384('abc'));

┌─HEX(SHA384('abc'))───────────────────────────────────────────────────────────────────────────────┐
│ CB00753F45A35E8BB5A03D699AC65007272C32AB0EDED1631A8B605A43FF5BED8086072BA1E7CC2358BAECA134C825A7 │
└──────────────────────────────────────────────────────────────────────────────────────────────────┘

SHA512

Introduced in: v1.1.0

Calculates the SHA512 hash of the given string.

Syntax

SHA512(s)

Arguments

s — The input string to hash String

Returned value

Returns the SHA512 hash of the given input string as a fixed-length string. FixedString(64)

Examples

Usage example

SELECT HEX(SHA512('abc'));

┌─HEX(SHA512('abc'))───────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ DDAF35A193617ABACC417349AE20413112E6FA4E89A97EA20A9EEEE64B55D39A2192992A274FC1A836BA3C23A3FEEBBD454D4423643CE80E2A9AC94FA54CA49F │
└──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

SHA512_256

Introduced in: v1.1.0

Calculates the SHA512_256 hash of the given string.

Syntax

SHA512_256(s)

Arguments

s — The input string to hash. String

Returned value

Returns the SHA512_256 hash of the given input string as a fixed-length string. FixedString(32)

Examples

Usage example

SELECT HEX(SHA512_256('abc'));

┌─HEX(SHA512_256('abc'))───────────────────────────────────────────┐
│ 53048E2681941EF99B2E29B76B4C7DABE4C2D0C634FC6D46E0E2F13107E7AF23 │
└──────────────────────────────────────────────────────────────────┘

URLHash

Introduced in: v1.1.0

A fast, decent-quality non-cryptographic hash function for a string obtained from a URL using some type of normalization.

This hash function has two modes:

Mode	Description
`URLHash(url)`	Calculates a hash from a string without one of the trailing symbols `/`,`?` or `#` at the end, if present.
`URLHash(url, N)`	Calculates a hash from a string up to the N level in the URL hierarchy, without one of the trailing symbols `/`,`?` or `#` at the end, if present. Levels are the same as in `URLHierarchy`.

Syntax

URLHash(url[, N])

Arguments

url — URL string to hash. String
N — Optional. Level in the URL hierarchy. (U)Int*

Returned value

Returns the computed hash value of url. UInt64

Examples

Usage example

SELECT URLHash('https://www.clickhouse.com')

┌─URLHash('https://www.clickhouse.com')─┐
│                  13614512636072854701 │
└───────────────────────────────────────┘

Hash of url with specified level

SELECT URLHash('https://www.clickhouse.com/docs', 0);
SELECT URLHash('https://www.clickhouse.com/docs', 1);

13614512636072854701
13167253331440520598

cityHash64

Introduced in: v1.1.0

Produces a 64-bit CityHash hash value.

This is a fast non-cryptographic hash function. It uses the CityHash algorithm for string parameters and implementation-specific fast non-cryptographic hash function for parameters with other data types. The function uses the CityHash combinator to get the final results.

Syntax

cityHash64(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed hash of the input arguments. UInt64

Examples

Call example

SELECT cityHash64(array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS CityHash, toTypeName(CityHash) AS type;

┌─────────────CityHash─┬─type───┐
│ 17177535963988450974 │ UInt64 │
└──────────────────────┴────────┘

Computing the checksum of the entire table with accuracy up to the row order

CREATE TABLE users (
    id UInt32,
    name String,
    age UInt8,
    city String
)
ENGINE = MergeTree
ORDER BY tuple();

INSERT INTO users VALUES
(1, 'Alice', 25, 'New York'),
(2, 'Bob', 30, 'London'),
(3, 'Charlie', 35, 'Tokyo');

SELECT groupBitXor(cityHash64(*)) FROM users;

┌─groupBitXor(cityHash64(id, name, age, city))─┐
│                         11639977218258521182 │
└──────────────────────────────────────────────┘

farmFingerprint64

Introduced in: v20.12.0

Produces a 64-bit FarmHash value using the Fingerprint64 method.

Syntax

farmFingerprint64(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed hash value of the input arguments. UInt64

Examples

Usage example

SELECT farmFingerprint64(array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS FarmFingerprint, toTypeName(FarmFingerprint) AS type;

┌──────FarmFingerprint─┬─type───┐
│ 16673609057812504858 │ UInt64 │
└──────────────────────┴────────┘

farmHash64

Introduced in: v1.1.0

Produces a 64-bit FarmHash using the Hash64 method.

Syntax

farmHash64(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed hash value of the input arguments. UInt64

Examples

Usage example

SELECT farmHash64(array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS FarmHash, toTypeName(FarmHash) AS type;

┌────────────FarmHash─┬─type───┐
│ 2663412879246289891 │ UInt64 │
└─────────────────────┴────────┘

gccMurmurHash

Introduced in: v20.1.0

Computes the 64-bit MurmurHash2 hash of the input value using the same seed as used by GCC.

It is portable between Clang and GCC builds.

Syntax

gccMurmurHash(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of arguments for which to compute the hash. Any

Returned value

Returns the calculated hash value of the input arguments. UInt64

Examples

Usage example

SELECT
    gccMurmurHash(1, 2, 3) AS res1,
    gccMurmurHash(('a', [1, 2, 3], 4, (4, ['foo', 'bar'], 1, (1, 2)))) AS res2

┌─────────────────res1─┬────────────────res2─┐
│ 12384823029245979431 │ 1188926775431157506 │
└──────────────────────┴─────────────────────┘

halfMD5

Introduced in: v1.1.0

Interprets all the input parameters as strings and calculates the MD5 hash value for each of them. Then combines hashes, takes the first 8 bytes of the hash of the resulting string, and interprets them as UInt64 in big-endian byte order. The function is relatively slow (5 million short strings per second per processor core).

Consider using the sipHash64 function instead.

The function takes a variable number of input parameters. Arguments can be any of the supported data types. For some data types calculated value of hash function may be the same for the same values even if types of arguments differ (integers of different size, named and unnamed Tuple with the same data, Map and the corresponding Array(Tuple(key, value)) type with the same data).

Syntax

halfMD5(arg1[, arg2, ..., argN])

Arguments

arg1[, arg2, ..., argN] — Variable number of arguments for which to compute the hash. Any

Returned value

Returns the computed half MD5 hash of the given input params returned as a UInt64 in big-endian byte order. UInt64

Examples

Usage example

SELECT HEX(halfMD5('abc', 'cde', 'fgh'));

┌─HEX(halfMD5('abc', 'cde', 'fgh'))─┐
│ 2C9506B7374CFAF4                  │
└───────────────────────────────────┘

hiveHash

Introduced in: v20.1.0

Calculates a “HiveHash” from a string. This is just JavaHash with zeroed out sign bits. This function is used in Apache Hive for versions before 3.0.

Syntax

hiveHash(arg)

Arguments

arg — Input string to hash. String

Returned value

Returns the computed “hive hash” of the input string. Int32

Examples

Usage example

SELECT hiveHash('Hello, world!');

┌─hiveHash('Hello, world!')─┐
│                 267439093 │
└───────────────────────────┘

icebergHash

Introduced in: v25.5.0

Implements the logic of the iceberg hashing transform

Syntax

icebergHash(value)

Arguments

value — Source value to take the hash of Integer or Bool or Decimal or Float* or String or FixedString or UUID or Date or Time or DateTime

Returned value

Returns a 32-bit Murmur3 hash, x86 variant, seeded with 0 Int32

Examples

Example

SELECT icebergHash(1.0 :: Float32)

-142385009

intHash32

Introduced in: v1.1.0

Calculates a 32-bit hash of an integer.

The hash function is relatively fast but not cryptographic hash function.

Syntax

intHash32(arg)

Arguments

arg — Integer to hash. (U)Int*

Returned value

Returns the computed 32-bit hash code of the input integer UInt32

Examples

Usage example

SELECT intHash32(42);

┌─intHash32(42)─┐
│    1228623923 │
└───────────────┘

intHash64

Introduced in: v1.1.0

Calculates a 64-bit hash of an integer.

The hash function is relatively fast (even faster than intHash32) but not a cryptographic hash function.

Syntax

intHash64(int)

Arguments

int — Integer to hash. (U)Int*

Returned value

64-bit hash code. UInt64

Examples

Usage example

SELECT intHash64(42);

┌────────intHash64(42)─┐
│ 11490350930367293593 │
└──────────────────────┘

javaHash

Introduced in: v20.1.0

Calculates JavaHash from:

Syntax

javaHash(arg)

Arguments

arg — Input value to hash. Any

Returned value

Returns the computed hash of arg Int32

Examples

Usage example 1

SELECT javaHash(toInt32(123));

┌─javaHash(toInt32(123))─┐
│                    123 │
└────────────────────────┘

Usage example 2

SELECT javaHash('Hello, world!');

┌─javaHash('Hello, world!')─┐
│               -1880044555 │
└───────────────────────────┘

javaHashUTF16LE

Introduced in: v20.1.0

Calculates JavaHash from a string, assuming it contains bytes representing a string in UTF-16LE encoding.

Syntax

javaHashUTF16LE(arg)

Arguments

arg — A string in UTF-16LE encoding. String

Returned value

Returns the computed hash of the UTF-16LE encoded string. Int32

Examples

Usage example

SELECT javaHashUTF16LE(convertCharset('test', 'utf-8', 'utf-16le'));

┌─javaHashUTF16LE(convertCharset('test', 'utf-8', 'utf-16le'))─┐
│                                                      3556498 │
└──────────────────────────────────────────────────────────────┘

jumpConsistentHash

Introduced in: v1.1.0

Calculates the jump consistent hash for an integer.

Syntax

jumpConsistentHash(key, buckets)

Arguments

key — The input key. UInt64
buckets — The number of buckets. Int32

Returned value

Returns the computed hash value. Int32

Examples

Usage example

SELECT jumpConsistentHash(256, 4)

┌─jumpConsistentHash(256, 4)─┐
│                          3 │
└────────────────────────────┘

kafkaMurmurHash

Introduced in: v23.4.0

Calculates the 32-bit MurmurHash2 hash of the input value using the same seed as used by Kafka and without the highest bit to be compatible with Default Partitioner.

Syntax

kafkaMurmurHash(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of parameters for which to compute the hash. Any

Returned value

Returns the calculated hash value of the input arguments. UInt32

Examples

Usage example

SELECT
    kafkaMurmurHash('foobar') AS res1,
    kafkaMurmurHash(array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS res2

┌───────res1─┬─────res2─┐
│ 1357151166 │ 85479775 │
└────────────┴──────────┘

keccak256

Introduced in: v25.4.0

Calculates the Keccak-256 cryptographic hash of the given string. This hash function is widely used in blockchain applications, particularly Ethereum.

Syntax

keccak256(message)

Arguments

message — The input string to hash. String

Returned value

Returns the 32-byte Keccak-256 hash of the input string as a fixed-length string. FixedString(32)

Examples

Usage example

SELECT hex(keccak256('hello'))

┌─hex(keccak256('hello'))──────────────────────────────────────────┐
│ 1C8AFF950685C2ED4BC3174F3472287B56D9517B9C948127319A09A7A36DEAC8 │
└──────────────────────────────────────────────────────────────────┘

kostikConsistentHash

Introduced in: v22.6.0

An O(1) time and space consistent hash algorithm by Konstantin ‘Kostik’ Oblakov. Only efficient with n <= 32768.

Syntax

kostikConsistentHash(input, n)

Aliases: yandexConsistentHash

Arguments

input — An integer key. UInt64
n — The number of buckets. UInt16

Returned value

Returns the computed hash value. UInt16

Examples

Usage example

SELECT kostikConsistentHash(16045690984833335023, 2);

┌─kostikConsistentHash(16045690984833335023, 2)─┐
│                                             1 │
└───────────────────────────────────────────────┘

metroHash64

Introduced in: v1.1.0

Produces a 64-bit MetroHash hash value.

Syntax

metroHash64(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed hash of the input arguments. UInt64

Examples

Usage example

SELECT metroHash64(array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS MetroHash, toTypeName(MetroHash) AS type;

┌────────────MetroHash─┬─type───┐
│ 16292826582821303855 │ UInt64 │
└──────────────────────┴────────┘

murmurHash2_32

Introduced in: v18.5.0

Computes the MurmurHash2 hash of the input value.

Syntax

murmurHash2_32(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed hash value of the input arguments. UInt32

Examples

Usage example

SELECT murmurHash2_32(array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS MurmurHash2, toTypeName(MurmurHash2) AS type;

┌─MurmurHash2─┬─type───┐
│  2947095100 │ UInt32 │
└─────────────┴────────┘

murmurHash2_64

Introduced in: v18.10.0

Computes the MurmurHash2 hash of the input value.

Syntax

murmurHash2_64(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed hash of the input arguments. UInt64

Examples

Usage example

SELECT murmurHash2_64(array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS MurmurHash2, toTypeName(MurmurHash2) AS type;

┌──────────MurmurHash2─┬─type───┐
│ 16479669305841206229 │ UInt64 │
└──────────────────────┴────────┘

murmurHash3_128

Introduced in: v18.10.0

Computes the 128-bit MurmurHash3 hash of the input value.

Syntax

murmurHash3_128(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed 128-bit MurmurHash3 hash value of the input arguments. FixedString(16)

Examples

Usage example

SELECT hex(murmurHash3_128('foo', 'foo', 'foo'));

┌─hex(murmurHash3_128('foo', 'foo', 'foo'))─┐
│ F8F7AD9B6CD4CF117A71E277E2EC2931          │
└───────────────────────────────────────────┘

murmurHash3_32

Introduced in: v18.10.0

Produces a MurmurHash3 hash value.

Syntax

murmurHash3_32(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed hash value of the input arguments. UInt32

Examples

Usage example

SELECT murmurHash3_32(array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS MurmurHash3, toTypeName(MurmurHash3) AS type;

┌─MurmurHash3─┬─type───┐
│   317985299 │ UInt32 │
└─────────────┴────────┘

murmurHash3_64

Introduced in: v18.10.0

Computes the MurmurHash3 hash of the input value.

Syntax

murmurHash3_64(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed hash value of the input arguments. UInt64

Examples

Usage example

SELECT murmurHash3_64(array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS MurmurHash3, toTypeName(MurmurHash3) AS type;

┌──────────MurmurHash3─┬─type───┐
│ 11285022984631508790 │ UInt64 │
└──────────────────────┴────────┘

ngramMinHash

Introduced in: v21.1.0

Splits a ASCII string into n-grams of ngramsize symbols and calculates hash values for each n-gram and returns a tuple with these hashes. Uses hashnum minimum hashes to calculate the minimum hash and hashnum maximum hashes to calculate the maximum hash. It is case sensitive.

Can be used to detect semi-duplicate strings with tupleHammingDistance. For two strings, if the returned hashes are the same for both strings, then those strings are the same.

Syntax

ngramMinHash(string[, ngramsize, hashnum])

Arguments

string — String for which to compute the hash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two hashes — the minimum and the maximum. Tuple

Examples

Usage example

SELECT ngramMinHash('ClickHouse') AS Tuple;

┌─Tuple──────────────────────────────────────┐
│ (18333312859352735453,9054248444481805918) │
└────────────────────────────────────────────┘

ngramMinHashArg

Introduced in: v21.1.0

Splits a ASCII string into n-grams of ngramsize symbols and returns the n-grams with minimum and maximum hashes, calculated by the ngramMinHash function with the same input. It is case sensitive.

Syntax

ngramMinHashArg(string[, ngramsize, hashnum])

Arguments

string — String for which to compute the hash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two tuples with hashnum n-grams each. Tuple(String)

Examples

Usage example

SELECT ngramMinHashArg('ClickHouse') AS Tuple;

┌─Tuple─────────────────────────────────────────────────────────────────────────┐
│ (('ous','ick','lic','Hou','kHo','use'),('Hou','lic','ick','ous','ckH','Cli')) │
└───────────────────────────────────────────────────────────────────────────────┘

ngramMinHashArgCaseInsensitive

Introduced in: v21.1.0

Splits a ASCII string into n-grams of ngramsize symbols and returns the n-grams with minimum and maximum hashes, calculated by the ngramMinHashCaseInsensitive function with the same input. It is case insensitive.

Syntax

ngramMinHashArgCaseInsensitive(string[, ngramsize, hashnum])

Arguments

string — String for which to compute the hash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two tuples with hashnum n-grams each. Tuple(Tuple(String))

Examples

Usage example

SELECT ngramMinHashArgCaseInsensitive('ClickHouse') AS Tuple;

┌─Tuple─────────────────────────────────────────────────────────────────────────┐
│ (('ous','ick','lic','kHo','use','Cli'),('kHo','lic','ick','ous','ckH','Hou')) │
└───────────────────────────────────────────────────────────────────────────────┘

ngramMinHashArgCaseInsensitiveUTF8

Introduced in: v21.1.0

Splits a UTF-8 string into n-grams of ngramsize symbols and returns the n-grams with minimum and maximum hashes, calculated by the ngramMinHashCaseInsensitiveUTF8 function with the same input. It is case insensitive.

Syntax

ngramMinHashArgCaseInsensitiveUTF8(string[, ngramsize, hashnum])

Arguments

string — String for which to compute the hash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two tuples with hashnum n-grams each. Tuple(Tuple(String))

Examples

Usage example

SELECT ngramMinHashArgCaseInsensitiveUTF8('ClickHouse') AS Tuple;

┌─Tuple─────────────────────────────────────────────────────────────────────────┐
│ (('ckH','ous','ick','lic','kHo','use'),('kHo','lic','ick','ous','ckH','Hou')) │
└───────────────────────────────────────────────────────────────────────────────┘

ngramMinHashArgUTF8

Introduced in: v21.1.0

Splits a UTF-8 string into n-grams of ngramsize symbols and returns the n-grams with minimum and maximum hashes, calculated by the ngramMinHashUTF8 function with the same input. It is case sensitive.

Syntax

ngramMinHashArgUTF8(string[, ngramsize, hashnum])

Arguments

string — String for which to compute the hash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two tuples with hashnum n-grams each. Tuple(Tuple(String))

Examples

Usage example

SELECT ngramMinHashArgUTF8('ClickHouse') AS Tuple;

┌─Tuple─────────────────────────────────────────────────────────────────────────┐
│ (('ous','ick','lic','Hou','kHo','use'),('kHo','Hou','lic','ick','ous','ckH')) │
└───────────────────────────────────────────────────────────────────────────────┘

ngramMinHashCaseInsensitive

Introduced in: v21.1.0

Splits a ASCII string into n-grams of ngramsize symbols and calculates hash values for each n-gram and returns a tuple with these hashes Uses hashnum minimum hashes to calculate the minimum hash and hashnum maximum hashes to calculate the maximum hash. It is case insensitive.

Can be used to detect semi-duplicate strings with tupleHammingDistance. For two strings, if the returned hashes are the same for both strings, then those strings are the same.

Syntax

ngramMinHashCaseInsensitive(string[, ngramsize, hashnum])

Arguments

string — String. String. - ngramsize — The size of an n-gram. Optional. Possible values: any number from 1 to 25. Default value: 3. UInt8. - hashnum — The number of minimum and maximum hashes used to calculate the result. Optional. Possible values: any number from 1 to 25. Default value: 6. UInt8.

Returned value

Tuple with two hashes — the minimum and the maximum. Tuple(UInt64, UInt64). Tuple

Examples

Usage example

SELECT ngramMinHashCaseInsensitive('ClickHouse') AS Tuple;

┌─Tuple──────────────────────────────────────┐
│ (2106263556442004574,13203602793651726206) │
└────────────────────────────────────────────┘

ngramMinHashCaseInsensitiveUTF8

Introduced in: v21.1.0

Splits a UTF-8 string into n-grams of ngramsize symbols and calculates hash values for each n-gram and returns a tuple with these hashes.. Uses hashnum minimum hashes to calculate the minimum hash and hashnum maximum hashes to calculate the maximum hash. It is case insensitive.

Can be used to detect semi-duplicate strings with tupleHammingDistance. For two strings, if the returned hashes are the same for both strings, then those strings are the same.

Syntax

ngramMinHashCaseInsensitiveUTF8(string [, ngramsize, hashnum])

Arguments

string — String for which to compute the hash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two hashes — the minimum and the maximum. Tuple

Examples

Usage example

SELECT ngramMinHashCaseInsensitiveUTF8('ClickHouse') AS Tuple;

┌─Tuple───────────────────────────────────────┐
│ (12493625717655877135,13203602793651726206) │
└─────────────────────────────────────────────┘

ngramMinHashUTF8

Introduced in: v21.1.0

Splits a UTF-8 string into n-grams of ngramsize symbols and calculates hash values for each n-gram and returns a tuple with these hashes. Uses hashnum minimum hashes to calculate the minimum hash and hashnum maximum hashes to calculate the maximum hash. It is case sensitive.

Can be used to detect semi-duplicate strings with tupleHammingDistance. For two strings, if the returned hashes are the same for both strings, then those strings are the same.

Syntax

ngramMinHashUTF8(string[, ngramsize, hashnum])

Arguments

string — String for which to compute the hash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two hashes — the minimum and the maximum. Tuple

Examples

Usage example

SELECT ngramMinHashUTF8('ClickHouse') AS Tuple;

┌─Tuple──────────────────────────────────────┐
│ (18333312859352735453,6742163577938632877) │
└────────────────────────────────────────────┘

ngramSimHash

Introduced in: v21.1.0

Splits a ASCII string into n-grams of ngramsize symbols and returns the n-gram simhash.

Can be used for detection of semi-duplicate strings with bitHammingDistance. The smaller the Hamming distance of the calculated simhashes of two strings, the more likely these strings are the same.

Syntax

ngramSimHash(string[, ngramsize])

Arguments

string — String for which to compute the case sensitive simhash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is3. UInt8

Returned value

Returns the computed hash of the input string. UInt64

Examples

Usage example

SELECT ngramSimHash('ClickHouse') AS Hash;

┌───────Hash─┐
│ 1627567969 │
└────────────┘

ngramSimHashCaseInsensitive

Introduced in: v21.1.0

Splits a ASCII string into n-grams of ngramsize symbols and returns the n-gram simhash. It is case insensitive.

Syntax

ngramSimHashCaseInsensitive(string[, ngramsize])

Arguments

string — String for which to compute the case insensitive simhash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is 3. UInt8

Returned value

Hash value. UInt64. UInt64

Examples

Usage example

SELECT ngramSimHashCaseInsensitive('ClickHouse') AS Hash;

┌──────Hash─┐
│ 562180645 │
└───────────┘

ngramSimHashCaseInsensitiveUTF8

Introduced in: v21.1.0

Splits a UTF-8 string into n-grams of ngramsize symbols and returns the n-gram simhash. It is case insensitive.

Can be used for detection of semi-duplicate strings with bitHammingDistance. The smaller is the Hamming Distance of the calculated simhashes of two strings, the more likely these strings are the same.

Syntax

ngramSimHashCaseInsensitiveUTF8(string[, ngramsize])

Arguments

string — String for which to compute the hash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is 3. UInt8

Returned value

Returns the computed hash value. UInt64

Examples

Usage example

SELECT ngramSimHashCaseInsensitiveUTF8('ClickHouse') AS Hash;

┌───────Hash─┐
│ 1636742693 │
└────────────┘

ngramSimHashUTF8

Introduced in: v21.1.0

Splits a UTF-8 encoded string into n-grams of ngramsize symbols and returns the n-gram simhash. It is case sensitive.

Syntax

ngramSimHashUTF8(string[, ngramsize])

Arguments

string — String for which to compute the hash. String
ngramsize — Optional. The size of an n-gram, any number from 1 to 25. The default value is 3. UInt8

Returned value

Returns the computed hash value. UInt64

Examples

Usage example

SELECT ngramSimHashUTF8('ClickHouse') AS Hash;

┌───────Hash─┐
│ 1628157797 │
└────────────┘

sipHash128

Introduced in: v1.1.0

Like sipHash64 but produces a 128-bit hash value, i.e. the final xor-folding state is done up to 128 bits.

Syntax

sipHash128(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns a 128-bit SipHash hash value. FixedString(16)

Examples

Usage example

SELECT hex(sipHash128('foo', '\x01', 3)) AS res;

┌─res──────────────────────────────┐
│ 9DE516A64A414D4B1B609415E4523F24 │
└──────────────────────────────────┘

sipHash128Keyed

Introduced in: v23.2.0

Same as sipHash128 but additionally takes an explicit key argument instead of using a fixed key.

Syntax

sipHash128Keyed((k0, k1), [arg1, arg2, ...])

Arguments

(k0, k1) — A tuple of two UInt64 values representing the key. Tuple(UInt64, UInt64)
arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

A 128-bit SipHash hash value of type FixedString(16). FixedString(16)

Examples

Usage example

SELECT hex(sipHash128Keyed((506097522914230528, 1084818905618843912), 'foo', '\x01', 3)) AS res;

┌─res──────────────────────────────┐
│ B8467F65C8B4CFD9A5F8BD733917D9BF │
└──────────────────────────────────┘

sipHash128Reference

Introduced in: v23.2.0

Like sipHash128 but implements the 128-bit algorithm from the original authors of SipHash.

Syntax

sipHash128Reference(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed 128-bit SipHash hash value of the input arguments. FixedString(16)

Examples

Usage example

SELECT hex(sipHash128Reference('foo', '\x01', 3)) AS res;

┌─res──────────────────────────────┐
│ C3AA2F3C06A14DBE3742E9107AA9765D │
└──────────────────────────────────┘

sipHash128ReferenceKeyed

Introduced in: v23.2.0

Same as sipHash128Reference but additionally takes an explicit key argument instead of using a fixed key.

Syntax

sipHash128ReferenceKeyed((k0, k1), arg1[, arg2, ...])

Arguments

(k0, k1) — Tuple of two values representing the key Tuple(UInt64, UInt64)
arg1[, arg2, ...] — A variable number of input arguments for which to compute the hash. Any

Returned value

Returns the computed 128-bit SipHash hash value of the input arguments. FixedString(16)

Examples

Usage example

SELECT hex(sipHash128ReferenceKeyed((506097522914230528, 1084818905618843912), 'foo', '\x01', 3)) AS res;

┌─res──────────────────────────────┐
│ 1D010CC83FB5460C25B556CE40992E61 │
└──────────────────────────────────┘

sipHash64

Introduced in: v1.1.0

Produces a 64-bit SipHash hash value.

This is a cryptographic hash function. It works at least three times faster than the MD5 hash function.

The function interprets all the input parameters as strings and calculates the hash value for each of them. It then combines the hashes using the following algorithm:

The first and the second hash value are concatenated to an array which is hashed.
The previously calculated hash value and the hash of the third input parameter are hashed in a similar way.
This calculation is repeated for all remaining hash values of the original input.

Syntax

sipHash64(arg1[, arg2, ...])

Arguments

arg1[, arg2, ...] — A variable number of input arguments. Any

Returned value

Returns a computed hash value of the input arguments. UInt64

Examples

Usage example

SELECT sipHash64(array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS SipHash, toTypeName(SipHash) AS type;

┌──────────────SipHash─┬─type───┐
│ 11348918044846389429 │ UInt64 │
└──────────────────────┴────────┘

sipHash64Keyed

Introduced in: v23.2.0

Like sipHash64 but additionally takes an explicit key argument instead of using a fixed key.

Syntax

sipHash64Keyed((k0, k1), arg1[,arg2, ...])

Arguments

(k0, k1) — A tuple of two values representing the key. Tuple(UInt64, UInt64)
arg1[,arg2, ...] — A variable number of input arguments. Any

Returned value

Returns the computed hash of the input values. UInt64

Examples

Usage example

SELECT sipHash64Keyed((506097522914230528, 1084818905618843912), array('e','x','a'), 'mple', 10, toDateTime('2019-06-15 23:00:00')) AS SipHash, toTypeName(SipHash) AS type;

┌─────────────SipHash─┬─type───┐
│ 8194087499447867747 │ UInt64 │
└─────────────────────┴────────┘

wordShingleMinHash

Introduced in: v21.1.0

Splits a ASCII string into parts (shingles) of shinglesize words, calculates hash values for each word shingle and returns a tuple with these hashes. Uses hashnum minimum hashes to calculate the minimum hash and hashnum maximum hashes to calculate the maximum hash. It is case sensitive.

Can be used to detect semi-duplicate strings with tupleHammingDistance. For two strings, if the returned hashes are the same for both strings, then those strings are the same.

Syntax

wordShingleMinHash(string[, shinglesize, hashnum])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two hashes — the minimum and the maximum. Tuple(UInt64, UInt64)

Examples

Usage example

SELECT wordShingleMinHash('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).') AS Tuple;

┌─Tuple──────────────────────────────────────┐
│ (16452112859864147620,5844417301642981317) │
└────────────────────────────────────────────┘

wordShingleMinHashArg

Introduced in: v1.1.0

Splits a ASCII string into parts (shingles) of shinglesize words each and returns the shingles with minimum and maximum word hashes, calculated by the wordShingleMinHash function with the same input. It is case sensitive.

Syntax

wordShingleMinHashArg(string[, shinglesize, hashnum])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two tuples with hashnum word shingles each. Tuple(Tuple(String))

Examples

Usage example

SELECT wordShingleMinHashArg('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).', 1, 3) AS Tuple;

┌─Tuple─────────────────────────────────────────────────────────────────┐
│ (('OLAP','database','analytical'),('online','oriented','processing')) │
└───────────────────────────────────────────────────────────────────────┘

wordShingleMinHashArgCaseInsensitive

Introduced in: v21.1.0

Splits a ASCII string into parts (shingles) of shinglesize words each and returns the shingles with minimum and maximum word hashes, calculated by the wordShingleMinHashCaseInsensitive function with the same input. It is case insensitive.

Syntax

wordShingleMinHashArgCaseInsensitive(string[, shinglesize, hashnum])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two tuples with hashnum word shingles each. Tuple(Tuple(String))

Examples

Usage example

SELECT wordShingleMinHashArgCaseInsensitive('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).', 1, 3) AS Tuple;

┌─Tuple──────────────────────────────────────────────────────────────────┐
│ (('queries','database','analytical'),('oriented','processing','DBMS')) │
└────────────────────────────────────────────────────────────────────────┘

wordShingleMinHashArgCaseInsensitiveUTF8

Introduced in: v21.1.0

Splits a UTF-8 string into parts (shingles) of shinglesize words each and returns the shingles with minimum and maximum word hashes, calculated by the wordShingleMinHashCaseInsensitiveUTF8 function with the same input. It is case insensitive.

Syntax

wordShingleMinHashArgCaseInsensitiveUTF8(string[, shinglesize, hashnum])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two tuples with hashnum word shingles each. Tuple(Tuple(String))

Examples

Usage example

SELECT wordShingleMinHashArgCaseInsensitiveUTF8('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).', 1, 3) AS Tuple;

┌─Tuple──────────────────────────────────────────────────────────────────┐
│ (('queries','database','analytical'),('oriented','processing','DBMS')) │
└────────────────────────────────────────────────────────────────────────┘

wordShingleMinHashArgUTF8

Introduced in: v21.1.0

Splits a UTF-8 string into parts (shingles) of shinglesize words each and returns the shingles with minimum and maximum word hashes, calculated by the wordShingleMinHashUTF8 function with the same input. It is case sensitive.

Syntax

wordShingleMinHashArgUTF8(string[, shinglesize, hashnum])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two tuples with hashnum word shingles each. Tuple(Tuple(String))

Examples

Usage example

SELECT wordShingleMinHashArgUTF8('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).', 1, 3) AS Tuple;

┌─Tuple─────────────────────────────────────────────────────────────────┐
│ (('OLAP','database','analytical'),('online','oriented','processing')) │
└───────────────────────────────────────────────────────────────────────┘

wordShingleMinHashCaseInsensitive

Introduced in: v21.1.0

Can be used to detect semi-duplicate strings with tupleHammingDistance. For two strings, if the returned hashes are the same for both strings, then those strings are the same.

Syntax

wordShingleMinHashCaseInsensitive(string[, shinglesize, hashnum])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two hashes — the minimum and the maximum. Tuple(UInt64, UInt64)

Examples

Usage example

SELECT wordShingleMinHashCaseInsensitive('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).') AS Tuple;

┌─Tuple─────────────────────────────────────┐
│ (3065874883688416519,1634050779997673240) │
└───────────────────────────────────────────┘

wordShingleMinHashCaseInsensitiveUTF8

Introduced in: v21.1.0

Splits a UTF-8 string into parts (shingles) of shinglesize words, calculates hash values for each word shingle and returns a tuple with these hashes. Uses hashnum minimum hashes to calculate the minimum hash and hashnum maximum hashes to calculate the maximum hash. It is case insensitive.

Can be used to detect semi-duplicate strings with tupleHammingDistance. For two strings, if the returned hashes are the same for both strings, then those strings are the same.

Syntax

wordShingleMinHashCaseInsensitiveUTF8(string[, shinglesize, hashnum])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two hashes — the minimum and the maximum. Tuple(UInt64, UInt64)

Examples

Usage example

SELECT wordShingleMinHashCaseInsensitiveUTF8('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).') AS Tuple;

┌─Tuple─────────────────────────────────────┐
│ (3065874883688416519,1634050779997673240) │
└───────────────────────────────────────────┘

wordShingleMinHashUTF8

Introduced in: v21.1.0

Can be used to detect semi-duplicate strings with tupleHammingDistance. For two strings, if the returned hashes are the same for both strings, then those strings are the same.

Syntax

wordShingleMinHashUTF8(string[, shinglesize, hashnum])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8
hashnum — Optional. The number of minimum and maximum hashes used to calculate the result, any number from 1 to 25. The default value is 6. UInt8

Returned value

Returns a tuple with two hashes — the minimum and the maximum. Tuple(UInt64, UInt64)

Examples

Usage example

SELECT wordShingleMinHashUTF8('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).') AS Tuple;

┌─Tuple──────────────────────────────────────┐
│ (16452112859864147620,5844417301642981317) │
└────────────────────────────────────────────┘

wordShingleSimHash

Introduced in: v21.1.0

Splits a ASCII string into parts (shingles) of shinglesize words and returns the word shingle simhash. Is is case sensitive.

Syntax

wordShingleSimHash(string[, shinglesize])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8

Returned value

Returns the computed hash value. UInt64

Examples

Usage example

SELECT wordShingleSimHash('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).') AS Hash;

┌───────Hash─┐
│ 2328277067 │
└────────────┘

wordShingleSimHashCaseInsensitive

Introduced in: v21.1.0

Splits a ASCII string into parts (shingles) of shinglesize words and returns the word shingle simhash. It is case insensitive.

Syntax

wordShingleSimHashCaseInsensitive(string[, shinglesize])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8

Returned value

Returns the computed hash value. UInt64

Examples

Usage example

SELECT wordShingleSimHashCaseInsensitive('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).') AS Hash;

┌───────Hash─┐
│ 2194812424 │
└────────────┘

wordShingleSimHashCaseInsensitiveUTF8

Introduced in: v1.1.0

Splits a UTF-8 encoded string into parts (shingles) of shinglesize words and returns the word shingle simhash. It is case insensitive.

Can be used for detection of semi-duplicate strings with bitHammingDistance. The smaller the Hamming Distance of the calculated simhashes of two strings, the more likely these strings are the same.

Syntax

wordShingleSimHashCaseInsensitiveUTF8(string[, shinglesize])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8

Returned value

Returns the computed hash value. UInt64

Examples

Usage example

SELECT wordShingleSimHashCaseInsensitiveUTF8('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).') AS Hash;

┌───────Hash─┐
│ 2194812424 │
└────────────┘

wordShingleSimHashUTF8

Introduced in: v21.1.0

Splits a UTF-8 string into parts (shingles) of shinglesize words and returns the word shingle simhash. It is case sensitive.

Syntax

wordShingleSimHashUTF8(string[, shinglesize])

Arguments

string — String for which to compute the hash. String
shinglesize — Optional. The size of a word shingle, any number from 1 to 25. The default value is 3. UInt8

Returned value

Returns the computed hash value. UInt64

Examples

Usage example

SELECT wordShingleSimHashUTF8('ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP).') AS Hash;

┌───────Hash─┐
│ 2328277067 │
└────────────┘

wyHash64

Introduced in: v22.7.0

Computes a 64-bit wyHash64 hash value.

Syntax

wyHash64(arg)

Arguments

arg — String argument for which to compute the hash. String

Returned value

Returns the computed 64-bit hash value UInt64

Examples

Usage example

SELECT wyHash64('ClickHouse') AS Hash;

12336419557878201794

xxHash32

Introduced in: v20.1.0

Calculates a xxHash from a string.

For the 64-bit version see xxHash64

Syntax

xxHash32(arg)

Arguments

arg — Input string to hash. String

Returned value

Returns the computed 32-bit hash of the input string. UInt32

Examples

Usage example

SELECT xxHash32('Hello, world!');

┌─xxHash32('Hello, world!')─┐
│                 834093149 │
└───────────────────────────┘

xxHash64

Introduced in: v20.1.0

Calculates a xxHash from a string.

For the 32-bit version see xxHash32

Syntax

xxHash64(arg)

Arguments

arg — Input string to hash. String

Returned value

Returns the computed 64-bit hash of the input string. UInt64

Examples

Usage example

SELECT xxHash64('Hello, world!');

┌─xxHash64('Hello, world!')─┐
│      17691043854468224118 │
└───────────────────────────┘

xxHash64Spark

Introduced in: v26.7.0

Calculates a xxHash from a string using the same seed as Spark.

This function is the same as xxHash64, but it uses seed 42 and returns the result as Int64. Only String and NULL inputs are supported. For NULL, the function returns 42, matching Spark’s seed behavior.

Syntax

xxHash64Spark(arg)

Arguments

arg — Input string to hash. String

Returned value

Returns the computed 64-bit hash of the input string. Int64

Examples

Usage example

SELECT xxHash64Spark('ABC');

┌─xxHash64Spark('ABC')─┐
│  4105715581806190027 │
└──────────────────────┘

xxh3

Introduced in: v22.12.0

Computes a XXH3 64-bit hash value.

Syntax

xxh3(expr)

Arguments

expr — A list of expressions of any data type. Any

Returned value

Returns the computed 64-bit xxh3 hash value UInt64

Examples

Usage example

SELECT xxh3('ClickHouse')

18009318874338624809

xxh3_128

Introduced in: v26.2.0

Computes a XXH3 128-bit hash value.

Syntax

xxh3_128(expr)

Arguments

expr — A list of expressions of any data type. Any

Returned value

Returns the computed 128-bit xxh3 hash value UInt128

Examples

Usage example

SELECT hex(xxh3_128('ClickHouse'))

14C27B7BEF95D36FECF5520CA2DAF030