PROBING A HASH TABLE USING VECTORIZED INSTRUCTIONS

摘要

Techniques for performing database operations using vectorized instructions are provided. In one technique, a hash table probe phase involves executing vectorized instructions to determine where in a bucket a particular key is located. This determination may be preceded by one or more vectorized instructions that are used to determine whether the bucket contains the particular key.

主权项

1. A method comprising:
while executing a join operation, probing a hash table based on keys from a second relation that is different than a first relation upon which the hash table is based; wherein probing the hash table comprises:
identifying a first key from the second relation;generating a hash value based on the first key;identifying, based on the hash value, in the hash table, a bucket that contains a plurality of keys;loading the plurality of keys into a first register;determining whether the first key matches a key in the plurality of keys;in response to determining that the key matches a particular key in the plurality of keys, using one or more vectorized instructions to determine a position, within the bucket, where the particular key is located; wherein the method is performed by one or more computing devices.