Aerospike's query and indexing capabilities play a crucial role in achieving its speed-at-scale objective. Queries are processed using one of three indexes: primary, set, or secondary indexes. Primary indexes are system-defined and cannot be removed or changed once created. Set indexes can improve performance for certain queries, while secondary indexes offer mapping from values to records and support indexing on custom values. Secondary indexes have limitations, such as not supporting uniqueness or order constraints. Pagination allows developers to retrieve results in smaller chunks, while parallel query processing enables distributed querying across partitions for improved throughput. Additionally, Aerospike supports read and write operations using indexes, with background updates providing an efficient way to update large numbers of records without blocking the application thread.