Adaptive early filtering with intra-pipeline predicate back-propagation

A method comprising:

• receiving a database command, the database command comprising a first operator, a join operator, and a clause, the clause limiting a number of elements output by the first operator, the first operator having input that is affected by results of the join operator;
• generating a query plan for the database command, the query plan comprising:
• a first query node corresponding to the first operator placed higher up in a pipeline than a second query node corresponding to the join operator;
• a third query node corresponding to the clause, the third query node defining a dynamic variable having a value based on elements in a data structure utilized by the first query node;
• and
• a fourth query node placed lower in the pipeline than the second query node, the fourth query node defining a filter based on the dynamic variable;
• and
• executing the query plan by passing one element at a time up the pipeline starting from a lowest query node in the pipeline.

A non-transitory machine-readable medium storing instructions which, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• receiving a database command, the database command comprising a first operator, a join operator, and a clause, the clause limiting a number of elements output by the first operator, the first operator having input that is affected by results of the join operator;
• generating a query plan for the database command, the query plan comprising:
• a first query node corresponding to the first operator placed higher up in a pipeline than a second query node corresponding to the join operator;
• a third query node corresponding to the clause, the third query node defining a dynamic variable having a value based on elements in a data structure utilized by the first query node;
• and
• a fourth query node placed lower in the pipeline than the second query node, the fourth query node defining a filter based on the dynamic variable;
• and
• executing the query plan by passing one element at a time up the pipeline starting from a lowest query node in the pipeline.