Abstract: Among other things, we describe a computer-implemented method, performed by a data processing system, of executing a computer program based on a query that is expressed in accordance with a query language applicable to a relational database, the computer program executed based at least in part on data stored in a tangible, non-transitory computer-readable medium, the executing including receiving a SQL query, where the SQL query includes an identifier associated with a resource that is external to the data processing system, generating a computer program based on the SQL query, and executing the computer program, causing transmitting one or more instructions to the resource, the instructions defining operations other than operations of the SQL query, and receiving data from the resource in response to the instructions.

Abstract: Among other things, a method of generating a computer program based on an SQL query includes receiving a SQL query, including a reference to a first data set stored at a first data source, and including a reference to a second data set stored at a second data source different from the first data source, determining that the SQL query includes two or more commands, the commands including a first union-type operation, and a first aggregation operation, and determining that the SQL query describes that the first union-type operation shall be applied to at least a portion of data from the first data set, and applied to at least a portion of data from the second data set, determining that the SQL query describes that the first aggregation operation shall be applied to data resulting from the first union-type operation, and generating the computer program.

Abstract: Among other things, we describe a computer-implemented method, performed by a data processing system, of executing a computer program based on a query that is expressed in accordance with a query language applicable to a relational database, the computer program executed based at least in part on data stored in a tangible, non-transitory computer-readable medium, the executing including receiving a SQL query, where the SQL query includes an identifier associated with a resource that is external to the data processing system, generating a computer program based on the SQL query, and executing the computer program, causing transmitting one or more instructions to the resource, the instructions defining operations other than operations of the SQL query, and receiving data from the resource in response to the instructions.

Abstract: In one aspect, in general, a computer-implemented method includes receiving an order-dependent list of rules generating a binary decision diagram based on the order-dependent list of rules, the binary decision diagram including decision nodes that include expressions including Boolean operators and operands, and generating an order-independent list of rules based on the binary decision diagram.

Abstract: One method includes receiving a database query, receiving information about a database table in data storage populated with data elements, producing a structural representation of the database table that includes a formatted data organization reflective of the database table and is absent the data elements of the database table, and providing the structural representation and the database query to a plan generator capable of producing a query plan representing operations for executing the database query on the database table. Another method includes receiving a query plan from a plan generator, the plan representing operations for executing a database query on a database table, and producing a dataflow graph from the query plan, wherein the dataflow graph includes at least one node that represents at least one operation represented by the query plan, and includes at least one link that represents at least one dataflow associated with the query plan.

Abstract: In a first aspect, a method includes, at a node of a Hadoop cluster, the node storing a first portion of data in HDFS data storage, executing a first instance of a data processing engine capable of receiving data from a data source external to the Hadoop cluster, receiving a computer-executable program by the data processing engine, executing at least part of the program by the first instance of the data processing engine, receiving, by the data processing engine, a second portion of data from the external data source, storing the second portion of data other than in HDFS storage, and performing, by the data processing engine, a data processing operation identified by the program using at least the first portion of data and the second portion of data.

Abstract: One method includes receiving a database query, receiving information about a database table in data storage populated with data elements, producing a structural representation of the database table that includes a formatted data organization reflective of the database table and is absent the data elements of the database table, and providing the structural representation and the database query to a plan generator capable of producing a query plan representing operations for executing the database query on the database table. Another method includes receiving a query plan from a plan generator, the plan representing operations for executing a database query on a database table, and producing a dataflow graph from the query plan, wherein the dataflow graph includes at least one node that represents at least one operation represented by the query plan, and includes at least one link that represents at least one dataflow associated with the query plan.

Abstract: In one aspect, in general, a method of generating a dataflow graph representing a database query includes receiving a query plan from a plan generator, the query plan representing operations for executing a database query on at least one input representing a source of data, producing a dataflow graph from the query plan, wherein the dataflow graph includes at least one node that represents at least one operation represented by the query plan, and includes at least one link that represents at least one dataflow associated with the query plan, and altering one or more components of the dataflow graph based on at least one characteristic of the at least one input representing the source of data.

Abstract: In a first aspect, a method includes, at a node of a Hadoop cluster, the node storing a first portion of data in HDFS data storage, executing a first instance of a data processing engine capable of receiving data from a data source external to the Hadoop cluster, receiving a computer-executable program by the data processing engine, executing at least part of the program by the first instance of the data processing engine, receiving, by the data processing engine, a second portion of data from the external data source, storing the second portion of data other than in HDFS storage, and performing, by the data processing engine, a data processing operation identified by the program using at least the first portion of data and the second portion of data.

Abstract: In one aspect, in general, a method of generating a dataflow graph representing a database query includes receiving a query plan from a plan generator, the query plan representing operations for executing a database query on at least one input representing a source of data, producing a dataflow graph from the query plan, wherein the dataflow graph includes at least one node that represents at least one operation represented by the query plan, and includes at least one link that represents at least one dataflow associated with the query plan, and altering one or more components of the dataflow graph based on at least one characteristic of the at least one input representing the source of data.

Abstract: Among other things, we describe a computer-implemented method, performed by a data processing system, of executing a computer program based on a query that is expressed in accordance with a query language applicable to a relational database, the computer program executed based at least in part on data stored in a tangible, non-transitory computer-readable medium, the executing including receiving a SQL query, where the SQL query includes an identifier associated with a resource that is external to the data processing system, generating a computer program based on the SQL query, and executing the computer program, causing transmitting one or more instructions to the resource, the instructions defining operations other than operations of the SQL query, and receiving data from the resource in response to the instructions.

Abstract: Among other things, a method of generating a computer program based on an SQL query includes receiving a SQL query, including a reference to a first data set stored at a first data source, and including a reference to a second data set stored at a second data source different from the first data source, determining that the SQL query includes two or more commands, the commands including a first union-type operation, and a first aggregation operation, and determining that the SQL query describes that the first union-type operation shall be applied to at least a portion of data from the first data set, and applied to at least a portion of data from the second data set, determining that the SQL query describes that the first aggregation operation shall be applied to data resulting from the first union-type operation, and generating the computer program.

Abstract: In a first aspect, a method includes, at a node of a Hadoop cluster, the node storing a first portion of data in HDFS data storage, executing a first instance of a data processing engine capable of receiving data from a data source external to the Hadoop cluster, receiving a computer-executable program by the data processing engine, executing at least part of the program by the first instance of the data processing engine, receiving, by the data processing engine, a second portion of data from the external data source, storing the second portion of data other than in HDFS storage, and performing, by the data processing engine, a data processing operation identified by the program using at least the first portion of data and the second portion of data.

Abstract: In one aspect, in general, a method of generating a dataflow graph representing a database query includes receiving a query plan from a plan generator, the query plan representing operations for executing a database query on at least one input representing a source of data, producing a dataflow graph from the query plan, wherein the dataflow graph includes at least one node that represents at least one operation represented by the query plan, and includes at least one link that represents at least one dataflow associated with the query plan, and altering one or more components of the dataflow graph based on at least one characteristic of the at least one input representing the source of data.

Abstract: In one aspect, in general, a method of generating a dataflow graph representing a database query includes receiving a query plan from a plan generator, the query plan representing operations for executing a database query on at least one input representing a source of data, producing a dataflow graph from the query plan, wherein the dataflow graph includes at least one node that represents at least one operation represented by the query plan, and includes at least one link that represents at least one dataflow associated with the query plan, and altering one or more components of the dataflow graph based on at least one characteristic of the at least one input representing the source of data.

Abstract: A method for supporting communication between a client and a server includes receiving a first message from a client. The method also includes creating an object in response to the first message. The method also includes sending a response to the first message to the client. The method also includes receiving changes to the object from a server. The method also includes storing the changes to the object. The method also includes receiving a second message from the client. The method also includes sending the stored changes to the client with a response to the second message.

Abstract: A method for supporting communication between a client and a server includes receiving a first message from a client. The method also includes creating an object in response to the first message. The method also includes sending a response to the first message to the client. The method also includes receiving changes to the object from a server. The method also includes storing the changes to the object. The method also includes receiving a second message from the client. The method also includes sending the stored changes to the client with a response to the second message.

Abstract: In one aspect, in general, a method of generating a dataflow graph representing a database query includes receiving a query plan from a plan generator, the query plan representing operations for executing a database query on at least one input representing a source of data, producing a dataflow graph from the query plan, wherein the dataflow graph includes at least one node that represents at least one operation represented by the query plan, and includes at least one link that represents at least one dataflow associated with the query plan, and altering one or more components of the dataflow graph based on at least one characteristic of the at least one input representing the source of data.

Abstract: One method includes receiving a database query, receiving information about a database table in data storage populated with data elements, producing a structural representation of the database table that includes a formatted data organization reflective of the database table and is absent the data elements of the database table, and providing the structural representation and the database query to a plan generator capable of producing a query plan representing operations for executing the database query on the database table. Another method includes receiving a query plan from a plan generator, the plan representing operations for executing a database query on a database table, and producing a dataflow graph from the query plan, wherein the dataflow graph includes at least one node that represents at least one operation represented by the query plan, and includes at least one link that represents at least one dataflow associated with the query plan.

Abstract: A method for supporting communication between a client and a server includes receiving a first message from a client. The method also includes creating an object in response to the first message. The method also includes sending a response to the first message to the client. The method also includes receiving changes to the object from a server. The method also includes storing the changes to the object. The method also includes receiving a second message from the client. The method also includes sending the stored changes to the client with a response to the second message.