Abstract: Techniques for performing machine learning inference calls in database query processing are described. A method for performing machine learning inference calls in database query processing may include generating a query plan to optimize a query for batch processing of data stored in a database service, the query plan including a batch mode operator to execute a function reference and an execution context associated with the batch mode operator, executing the query plan to invoke a function associated with the function reference, wherein the function sends a batch of requests, generated using the execution context, to a remote service and obtains a plurality of responses from the remote service, and generating a query response based on the plurality of responses.

Abstract: Intelligent query routing may be performed across shards of a scalable database table. A router of a database system may receive an access request directed to one or more database tables. The router may evaluate the access request with respect to metadata obtained for the database tables to determine an assignment distribution of computing resources of the database system to data that can satisfy the access request. The router can select planning locations to perform the access request based on the assignment distribution of the computing resources. The router can cause the access request to be performed according to planning at the selected planning locations.

Abstract: Techniques for batch mode execution for calls to remote services are described. A method of batch mode execution for calls to remote services may include generating, by a query service of a provider network, a query plan to optimize a query for batch processing of data, the query plan including at least a function reference to a function provided by at least one service of the provider network, executing the query plan to invoke the function associated with the function reference, wherein a batch function generates a request including a batch of service calls to be processed by the at least one service, sends the request including the batch of service calls to the at least one service, and obtains a plurality of machine learning responses from the at least one service, and generating a query response based on the plurality of responses.

Abstract: In an example, a transitive local predicates may be inferred across multiple joins, wherein the multiple outer joins include multiple outer joins. A query connecting tables by the multiple joins is analyzed. A local predicate may then be identified from the analyzed query and may be determined to be either a where-clause local predicate or an on-clause local predicate. Accordingly, a transitive local predicate may be inferred across a selection of the tables based on the determination.

Abstract: Described are methods for data compression of a column store database. A method may include providing a plurality of columns sorted from a first position to a last position in increasing order of individual cardinality, permuting columns of the plurality of columns one-by-one to a second position of the plurality of columns, except for the column at the first position, to determine a first permutation of the plurality of columns having the greatest run-length encoding (RLE) compression, and permuting columns of the first permutation one-by-one to a third position, except for columns at the second position and the first position, to determine a second permutation having the greatest RLE compression. The method may further include continuing permuting the plurality of columns to determine a final sort order, and compressing columns of the final sort order using RLE compression.

Abstract: In an example, a transitive local predicates may be inferred across multiple joins, wherein the multiple outer joins include multiple outer joins. A query connecting tables by the multiple joins is analyzed. A local predicate may then be identified from the analyzed query and may be determined to be either a where-clause local predicate or an on-clause local predicate. Accordingly, a transitive local predicate may be inferred across a selection of the tables based on the determination.