IMMEDIATE JOIN SPILLING SCHEME FOR A DATABASE

摘要

Embodiments relate to an immediate join spilling scheme for a database. An aspect includes receiving a command to perform a join of an inner table and an outer table in a database. Another aspect includes spilling a plurality of hash tables to a disk memory, each hash table corresponding to a respective inner table partition. Another aspect includes registering, by a first agent of a plurality of agents, a set of inner table partitions that require processing by the first agent to complete the join for a first stride of rows of the outer table. Another aspect includes, based on determining that a hash table corresponding to a registered inner table partition of the first agent has been loaded into the local memory by the second agent of the plurality of agents, performing the join of the loaded hash table and the first stride of rows of the outer table by the first agent.

主权项

1. A method comprising:
receiving a command to perform a join of an inner table and an outer table in a database; and performing the join using an immediate join spilling scheme, the immediate join spilling scheme comprising:
spilling a plurality of hash tables to a disk memory, each hash table corresponding to a respective inner table partition;registering, by a first agent of a plurality of agents that are associated with the join, a set of inner table partitions that require processing by the first agent to complete the join for a first stride of rows of the outer table;determining whether a hash table corresponding to a registered inner table partition of the first agent has been loaded into a local memory by a second agent of the plurality of agents; andbased on determining that a hash table corresponding to a registered inner table partition of the first agent has been loaded into the local memory by the second agent of the plurality of agents, performing the join of the loaded hash table and the first stride of rows of the outer table by the first agent.