Abstract: In some examples, a database system accesses a plurality of objects in a remote object store. In response to a query to change data in a first object of the plurality of objects, the database system specifies the first object prior to the change as a first version of the first object, and creates a second version of the first object after the change. The database system maintains metadata identifying unmodified objects of the plurality of objects, and during a garbage collection process when deciding whether to remove a given object of the plurality of objects, accesses the metadata to determine whether the given object has been modified, and prevents removal of the given object in response to determining that the given object is unmodified.

Abstract: A database system includes a storage medium to store a semi-materialized view (MV) defined on an MV condition, the semi-MV including metadata containing references to objects containing data of one or more tables that satisfy the MV condition, the objects stored in a remote data store that is coupled to the database system over a network. The database system includes at least one processor to receive a query including a query condition, determine that the semi-MV can be used to satisfy the query based on the MV condition and the query condition, and use the metadata in the semi-MV to retrieve data of the objects in the remote data store for the query.

Abstract: In some examples, a database system includes a memory to store a predicate-object name cache, where the predicate-object name cache contains predicates mapped to respective object names. The database system further includes at least one processor to receive a query containing a given predicate, identify, based on accessing the predicate-object name cache, one or more object names indicated by the predicate-object name cache as being relevant for the given predicate, retrieve one or more objects identified by the one or more object names from a remote data store, and process the query with respect to data records of the one or more objects retrieved from the remote data store.

Abstract: In some examples, a database system includes a storage medium to store a materialized view (MV) that includes data satisfying an MV condition. At least one processor is to receive a query including a query condition, determine that the query condition partially matches the MV condition, and access a part of the data in the MV partially satisfy the query.

Abstract: In some examples, a database system includes a memory to store a predicate-object name cache, where the predicate-object name cache contains predicates mapped to respective object names. The database system further includes at least one processor to receive a query containing a given predicate, identify, based on accessing the predicate-object name cache, one or more object names indicated by the predicate-object name cache as being relevant for the given predicate, retrieve one or more objects identified by the one or more object names from a remote data store, and process the query with respect to data records of the one or more objects retrieved from the remote data store.

Abstract: In some examples, a database system includes a storage medium to store a materialized view (MV) that includes data satisfying an MV condition. At least one processor is to receive a query including a query condition, determine that the query condition partially matches the MV condition, and access a part of the data in the MV to partially satisfy the query.