28. In a continuous computation system, a method for distributing processing of a query over a cluster of servers, where the query subscribes to at least one input data stream, the method comprising: determining whether input messages for the query can be partitioned into groups that can be processed independent of each other by analyzing the semantics of the query; and in response to determining that input messages for the query can be partitioned into groups that can be processed independent of each other: installing identical logic for processing the query on two of more servers in the cluster, wherein such logic is installed prior to processing input messages; continuously running the query logic on such servers; receiving, at the continuous computation system, streaming input messages on one or more data streams, wherein input messages can arrive continuously; distributing the input messages among such servers by such groups, wherein messages are distributed while the query is running; generating partial outputs for the query on such servers; and combining such partial outputs to generate output data for the query.
28. In a continuous computation system, a method for distributing processing of a query over a cluster of servers, where the query subscribes to at least one input data stream, the method comprising: determining whether input messages for the query can be partitioned into groups that can be processed independent of each other by analyzing the semantics of the query; and in response to determining that input messages for the query can be partitioned into groups that can be processed independent of each other: installing identical logic for processing the query on two of more servers in the cluster, wherein such logic is installed prior to processing input messages; continuously running the query logic on such servers; receiving, at the continuous computation system, streaming input messages on one or more data streams, wherein input messages can arrive continuously; distributing the input messages among such servers by such groups, wherein messages are distributed while the query is running; generating partial outputs for the query on such servers; and combining such partial outputs to generate output data for the query. 33. The method of claim 28 , where, in generating the partial outputs, the query operates on the input messages in accordance with a row-based window.