Abstract: In some embodiments, a system is provided, comprising: memory storing instructions that, when executed, cause a processor to: submit a first database query; receive a runtime to execute the first database query using a plan selected by a query optimizer; receive runtimes to execute the first database query using a plurality of test plans; determine, based on the runtimes, a metric indicative of the effectiveness of the query optimizer; and cause the metric indicative of the effectiveness of the query optimizer to be presented to a user.

Abstract: In some examples, candidate projection enumeration based query response generation may include obtaining a query, and identifying, based on the query, a plurality of candidate columns from at least one table to respond to the query. Using a tree-based model, the candidate columns may be analyzed to generate a candidate set of projections to respond to the query. Each candidate projection of the candidate set of projections may include a sort order associated with at least one candidate column of the candidate columns, a segmentation key value associated with at least one candidate column of the candidate columns, and a replication value associated with the candidate projection. Based on the candidate set of projections, a response to the query may be generated.

Abstract: In some examples, candidate projection enumeration based query response generation may include obtaining a query, and identifying, based on the query, a plurality of candidate columns from at least one table to respond to the query. Using a tree-based model, the candidate columns may be analyzed to generate a candidate set of projections to respond to the query. Each candidate projection of the candidate set of projections may include a sort order associated with at least one candidate column of the candidate columns, a segmentation key value associated with at least one candidate column of the candidate columns, and a replication value associated with the candidate projection. Based on the candidate set of projections, a response to the query may be generated.

Abstract: Methods, systems, and media for distributing database queries across a metered virtual network are provided, the method comprising: receiving a first query at a first time; selecting, using probabilistic models, a first virtual machine to execute the first query, each of the probabilistic models associated with one of a plurality of virtual machines; receiving information indicative of a monetary cost of executing the first query based at least in part on the execution time of the first query by the first virtual machine; providing an observation to each of the plurality of probabilistic models, wherein the observation includes at least information about the cost of executing the first query, and information about an action selected by the probabilistic model in connection with the first query; and reducing, over time, the costs of using the metered virtual network to execute queries received after the first query based on the observations.

Abstract: Systems, methods, and media for measuring the effectiveness and efficiency of database query optimizers are provided. In some embodiments, a system is provided, comprising: memory storing instructions that, when executed, cause a processor to: submit a first database query; receive a runtime to execute the first database query using a plan selected by a query optimizer; receive runtimes to execute the first database query using a plurality of test plans; determine, based on the runtimes, a metric indicative of the effectiveness of the query optimizer; and cause the metric indicative of the effectiveness of the query optimizer to be presented to a user.

Abstract: A method of providing a deployment plan for a query in a distributed shared stream processing system includes storing a set of feasible deployment plans for a query that is currently deployed in the stream processing system. A query includes a plurality of operators hosted on nodes in the stream processing system providing a data stream responsive to a client request for information. The method also includes determining whether a QoS metric constraint for the query is violated, and selecting a deployment plan from the set of feasible deployment plans to be used for providing the query in response to determining the QoS metric constraint is violated.