Custom table scan for top k queries

A method comprising:

• receiving a query request including a top k query operator for query plan generation, optimization, and execution, wherein k defines a threshold limit of query results for the top k query operator;
• inserting into a query plan a check operator associated with the top k query operator;
• in response to executing the query plan, checking, by the check operator, whether an early exit occurs due to the top k query operator reaching the threshold limit;
• orchestrating, by the check operator, an order in which low level operators of the query plan are executed to load fragments of a database table into an in-memory portion of a database execution engine;
• in response to the early exit occurring due to the top k query operator reaching the threshold limit, stopping processing, by the check operator, including opening of another fragment of a database table;
• in response to the early exit not occurring, allowing, by the check operator, the opening of the other fragment of the database table;
• and
• returning, as a query result, a result set of the top k results.

A non-transitory computer-readable storage medium including instructions which, when executed by at least one data processor, cause operations comprising:

• receiving a query request including a top k query operator for query plan generation, optimization, and execution, wherein k defines a threshold limit of query results for the top k query operator;
• inserting into a query plan a check operator associated with the top k query operator;
• in response to executing the query plan, checking, by the check operator, whether an early exit occurs due to the top k query operator reaching the threshold limit;
• orchestrating, by the check operator, an order in which low level operators of the query plan are executed to load fragments of a database table into an in-memory portion of a database execution engine;
• in response to the early exit occurring due to the top k query operator reaching the threshold limit, stopping processing, by the check operator, including opening of another fragment of a database table;
• in response to the early exit not occurring, allowing, by the check operator, the opening of the other fragment of the database table;
• and
• returning, as a query result, a result set of the top k results.