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MurmurHash3 functions in the Hashfuncs DuckDB extension

Function category

MurmurHash3

3 functions

Austin Appleby's [MurmurHash3](https://github.com/aappleby/smhasher) — a battle-tested non-cryptographic hash widely used in distributed systems including [Apache Cassandra](https://cassandra.apache.org/_/index.html), [Apache Spark](https://spark.apache.org/), and many partitioner implementations. Choose [`murmurhash3_32`](#murmurhash3_32), [`murmurhash3_128`](#murmurhash3_128), or [`murmurhash3_x64_128`](#murmurhash3_x64_128) when you need to interoperate with an existing MurmurHash3-based consumer.

murmurhash3_128

Scalar function MurmurHash3
Signature
2 overloaded forms · click to inspect
Arguments (Positional)
Argument value Type ANY Mode Positional Description
Description

128-bit MurmurHash3 — the x86 variant. Returns a UHUGEINT covering both 64-bit halves of the hash.

Included for compatibility with consumers that specifically expect the x86 128-bit form. On modern 64-bit hardware, murmurhash3_x64_128 is generally the right pick.

1 128-bit on x86 
SELECT murmurhash3_128('hello world');

Output

murmurhash3_128('hello world')
206095855024402301784664199839047883400
2 Seeded 
SELECT murmurhash3_128('hello world', 42);

Output

murmurhash3_128('hello world', 42)
49935197742640446573784908445156827108
Related functions

murmurhash3_32

Scalar function MurmurHash3
Signature
2 overloaded forms · click to inspect
Arguments (Positional)
Argument value Type ANY Mode Positional Description
Description

32-bit MurmurHash3. Battle-tested across distributed systems — variants of MurmurHash3 underpin hash partitioning in Apache Cassandra, Apache Spark, and many other tools.

Choose murmurhash3_32 when you need cross-system compatibility with an existing MurmurHash3-32 consumer. For new in-DuckDB workloads, xxh3_64 is generally faster.

1 Default 
SELECT murmurhash3_32('hello world');

Output

murmurhash3_32('hello world')
1586663183
2 Seeded 
SELECT murmurhash3_32('hello world', 123);

Output

murmurhash3_32('hello world', 123)
679062093
Related functions

murmurhash3_x64_128

Scalar function MurmurHash3
Signature
2 overloaded forms · click to inspect
Arguments (Positional)
Argument value Type ANY Mode Positional Description
Description

128-bit MurmurHash3 — the x64 variant. The standard 128-bit MurmurHash3 form on 64-bit platforms; this is what most modern consumers (including Apache Cassandra's Murmur3Partitioner and Apache Spark's default hash partitioner) actually use.

Returned as a UHUGEINT. Use this when DuckDB needs to produce hashes that match what another system has already computed for the same key.

1 128-bit hash optimized for x64 
SELECT murmurhash3_x64_128('hello world');

Output

murmurhash3_x64_128('hello world')
228083453807047072434243676435732455694
2 Seeded 
SELECT murmurhash3_x64_128('hello world', 42);

Output

murmurhash3_x64_128('hello world', 42)
177772143293161058141827116100740741312
Related functions