On-demand access of database table partitions

A computer-implemented method, comprising:

• receiving a query for accessing a first database table stored at a database, the first database table comprising a first partition and a second partition;
• determining, by using a data execution engine, an execution plan of the query, the execution plan comprising a first operation;
• responding to the query by at least acquiring a lock on the first database table without loading the first partition or the second partition into a main memory of the database;
• identifying, based at least on a filter predicate imposed by the query, the second partition as an unused partition not necessary for executing the query, the filter predicate being imposed on a column of the first database table that is a part of the partitioning criteria, and the second partition being identified as the unused partition based at least on the second partition being occupied by records that fail to satisfy the filter predicate;
• and
• delegating, to a first operator, an execution of the first operation of the execution plan of the query, the first operator determining usage of the first partition for execution of the first operation of the execution plan, the first operator loading the first partition into the main memory, and deferring loading of the second partition, into the main memory, to a later point in time when the first operator is able to determine whether the first operation is executable without the second partition.

A non-transitory computer readable medium storing instructions, which when executed by at least on data processor, result in operations comprising:

• receiving a query for accessing a database table stored at a database, the database table comprising a first partition and a second partition;
• determining, by using a data execution engine, an execution plan of the query, the execution plan comprising a first operation;
• responding to the query by at least acquiring a lock on the database table without loading the first partition or the second partition into a main memory of the database;
• identifying, based at least on a filter predicate imposed by the query, the second partition as an unused partition not necessary for executing the query, the filter predicate being imposed on a column of the first database table that is a part of the partitioning criteria, and the second partition being identified as the unused partition based at least on the second partition being occupied by records that fail to satisfy the filter predicate;
• and
• delegating, to a first operator, an execution of the first operation of the execution plan of the query, the first operator determining usage of the first partition for execution of the first operation of the execution plan, the first operator loading the first partition into the main memory, and deferring loading of the second partition, into the main memory, to a later point in time when the first operator is able to determine whether the first operation is executable without the second partition.