Processing of deterministic user-defined functions using multiple corresponding hash tables

A computer-implemented method for processing a deterministic user-defined function (UDF), the method comprising the steps of:

• (A) collecting historical access patterns that indicate how the deterministic UDF accesses at least one database table;
• and
• (B) allocating a plurality of hash tables to the deterministic UDF based on the historical access patterns by performing the steps of:
• evaluating columns passed to the deterministic UDF;
• grouping similar columns together and disjoint columns apart;
• and
• allocating one of the plurality of hash tables to each group of columns.

A computer-implemented method for processing a deterministic user-defined function (UDF), the method comprising the steps of:

• (A) collecting historical access patterns that indicate how the deterministic UDF accessed a plurality of columns in at least one database table;
• (B) evaluating columns passed to the deterministic UDF from the historical access patterns;
• (C) grouping from step (B) similar columns together and disjoint columns apart;
• (D) allocating one of a plurality of hash tables to each group of columns in step (C);
• (E) dynamically adjusting the allocation of the plurality of hash tables in step (D) according to the historical access patterns as the historical access patterns change over time;
• (F) determining from user-specified criteria whether to save the allocation of the plurality of hash tables for use with a plurality of queries wherein the user-specified criteria includes performance characteristics, user option to turn on or off, user-specified conditions, application identifier, user identifier, and custom conditions;
• and
• (G) if the user-specified criteria specifies to save the allocation of the plurality of hash tables for use with the plurality of queries, saving the allocation of the plurality of hash tables for use with the plurality of queries.