Hash Functions

Apache Pinot provides a suite of hash functions to compute various hash values for data transformation within queries. These functions support cryptographic hashes (e.g., SHA, MD5) and non-cryptographic hashes (e.g., Murmur, Adler, CRC). Below is a detailed reference for each function.

Cryptographic Hash Functions

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SHA

Computes the SHA-1 hash of the input.

Syntax

SHA(input)

Parameters

• input (BYTES): Input byte array to hash.

Returns

• STRING: SHA-1 hash as a lowercase hex string.

Example

SELECT SHA(TO_UTF8('testString')) FROM myTable
-- Returns '956265657d0b637ef65b9b59f9f858eecf55ed6a'

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SHA224

Computes the SHA-224 hash of the input.

Syntax

SHA224(input)

Parameters

• input (BYTES): Input byte array to hash.

Returns

• STRING: SHA-224 hash as a lowercase hex string.

Example

SELECT SHA224(TO_UTF8('testString')) FROM myTable
-- Returns 'bb54d1095764bff72b570dcdc3172ed6d1b26695494528a0059c95ae'

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SHA256

Computes the SHA-256 hash of the input.

Syntax

SHA256(input)

Parameters

• input (BYTES): Input byte array to hash.

Returns

• STRING: SHA-256 hash as a lowercase hex string.

Example

SELECT SHA256(TO_UTF8('testString')) FROM myTable
-- Returns '4acf0b39d9c4766709a3689f553ac01ab550545ffa4544dfc0b2cea82fba02a3'

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SHA512

Computes the SHA-512 hash of the input.

Syntax

SHA512(input)

Parameters

• input (BYTES): Input byte array to hash.

Returns

• STRING: SHA-512 hash as a lowercase hex string.

Example

SELECT SHA512(TO_UTF8('testString')) FROM myTable
-- Returns 'c48af5a7f6d4a851fc8a434eed638ab1a6ef68e19dbcae894ac67c9fbc5bcb0182b8e7123b3df3c9e4dcb7690c23103f03dc17f54352071ceb2a4eb204b26b91'

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MD2

Computes the MD2 hash of the input.

Syntax

MD2(input)

Parameters

• input (BYTES): Input byte array to hash.

Returns

• STRING: MD2 hash as a lowercase hex string.

Example

SELECT MD2(TO_UTF8('testString')) FROM myTable
-- Returns '466c453913ba0d8325f96b2d47984fb5'

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MD5

Computes the MD5 hash of the input.

Syntax

MD5(input)

Parameters

• input (BYTES): Input byte array to hash.

Returns

• STRING: MD5 hash as a lowercase hex string.

Example

SELECT MD5(TO_UTF8('testString')) FROM myTable
-- Returns '536788f4dbdffeecfbb8f350a941eea3'

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Non-Cryptographic Hash Functions

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MurmurHash2

Computes a 32-bit MurmurHash2 value.

Syntax

MURMURHASH2(input)

Parameters

• input (BYTES): Input byte array to hash.

Returns

• INT: 32-bit hash value (signed integer).

Example

SELECT MURMURHASH2(TO_UTF8('testString')) FROM myTable
-- Returns -534425817

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MurmurHash2UTF8

Computes a 32-bit MurmurHash2 value for a UTF-8 string.

Syntax

MURMURHASH2UTF8(input)

Parameters

• input (STRING): Input string (converted to UTF-8 bytes).

Returns

• INT: 32-bit hash value (signed integer).

Example

SELECT MURMURHASH2UTF8('testString') FROM myTable
-- Returns -534425817

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MurmurHash2Bit64

Computes a 64-bit MurmurHash2 value. Two overloads are supported:

Syntax 1 (No Seed)

MURMURHASH2BIT64(input)

Syntax 2 (With Seed)

MURMURHASH2BIT64(input, seed)

Parameters

• input (BYTES): Input byte array to hash.

• seed (INT, optional): Seed value for the hash function.

Returns

• LONG: 64-bit hash value (signed long).

Examples

SELECT MURMURHASH2BIT64(TO_UTF8('testString')) FROM myTable
-- Returns 3907736674355139845

SELECT MURMURHASH2BIT64(TO_UTF8('testString'), 12345) FROM myTable
-- Returns -2138976126980760436

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MurmurHash3Bit32

Computes a 32-bit MurmurHash3 value with a seed.

Syntax

MURMURHASH3BIT32(input, seed)

Parameters

• input (BYTES): Input byte array to hash.

• seed (INT): Seed value for the hash function.

Returns

• INT: 32-bit hash value (signed integer).

Example

SELECT MURMURHASH3BIT32(TO_UTF8('testString'), 0) FROM myTable
-- Returns -1435605585

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MurmurHash3Bit64

Computes a 64-bit MurmurHash3 value with a seed.

Syntax

MURMURHASH3BIT64(input, seed)

Parameters

• input (BYTES): Input byte array to hash.

• seed (INT): Seed value for the hash function.

Returns

• LONG: 64-bit hash value (signed long).

Example

SELECT MURMURHASH3BIT64(TO_UTF8('testString'), 0) FROM myTable
-- Returns -3652179990542706350

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MurmurHash3Bit128

Computes a 128-bit MurmurHash3 value with a seed.

Syntax

MURMURHASH3BIT128(input, seed)

Parameters

• input (BYTES): Input byte array to hash.

• seed (INT): Seed value for the hash function.

Returns

• BYTES: 128-bit hash as a 16-byte array.

Example

SELECT MURMURHASH3BIT128(TO_UTF8('testString'), 0) FROM myTable
-- Returns byte array: [82, -103, -23, 15, -90, -39, 80, -51, 15, 73, -81, -28, 111, -21, -78, 108]

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MurmurHash3X64Bit32 (x64 Optimized)

Computes a 32-bit MurmurHash3 optimized for x64 platforms.

Syntax

MURMURHASH3X64BIT32(input, seed)

Parameters

• input (BYTES): Input byte array to hash.

• seed (INT): Seed value for the hash function.

Returns

• INT: 32-bit hash value (signed integer).

Example

SELECT MURMURHASH3X64BIT32(TO_UTF8('testString'), 0) FROM myTable
-- Returns -1096986291

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MurmurHash3X64Bit128 (x64 Optimized)

Computes a 128-bit MurmurHash3 optimized for x64 platforms.

Syntax

MURMURHASH3X64BIT128(input, seed)

Parameters

• input (BYTES): Input byte array to hash.

• seed (INT): Seed value for the hash function.

Returns

• BYTES: 128-bit hash as a 16-byte array.

Example

SELECT MURMURHASH3X64BIT128(TO_UTF8('testString'), 0) FROM myTable
-- Returns byte array: [-66, -99, 81, 77, -7, 29, 124, 76, 42, 38, -34, -42, -92, -83, 83, 13]

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Adler32

Computes a 32-bit Adler checksum.

Syntax

ADLER32(input)

Parameters

• input (BYTES): Input byte array to hash.

Returns

• INT: 32-bit Adler checksum (signed integer).

Example

SELECT ADLER32(TO_UTF8('testString')) FROM myTable
-- Returns 392102968

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CRC32

Computes a 32-bit CRC (Cyclic Redundancy Check).

Syntax

CRC32(input)

Parameters

• input (BYTES): Input byte array to hash.

Returns

• INT: 32-bit CRC32 value (signed integer).

Example

SELECT CRC32(TO_UTF8('testString')) FROM myTable
-- Returns 418708744

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CRC32C

Computes a 32-bit CRC32C (Castagnoli).

Syntax

CRC32C(input)

Parameters

• input (BYTES): Input byte array to hash.

Returns

• INT: 32-bit CRC32C value (signed integer).

Example

SELECT CRC32C(TO_UTF8('testString')) FROM myTable
-- Returns -1608760557

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Notes

1. Input Conversion: Use TO_UTF8(string) to convert strings to BYTES where required.

2. Negative Values: Hash functions return signed integers/longs. Use CAST to interpret them as unsigned if needed.

3. Byte Arrays: Functions like MURMURHASH3BIT128 return BYTES as a 16-byte array.

4. Platform-Specific Variants: Functions like MURMURHASH3X64BIT32/64/128 are optimized for x64 architectures. The results could be different cross platform.