Abstract: Methods, systems, and computer-readable storage media for receiving, from a database client, an asynchronous lookup request including a key representative of a query and, in response, returning a value handle including a value promise, receiving, from the database client, a get request based on the value promise, determining that a query result corresponding to the key is unavailable in a results cache and that the key is in an unlocked state, and in response, returning a null pointer and a first key lock status to the first database client, receiving, from the database client, a key, value pair including the key and a value, the value comprising the query result, and storing the key, value pair in the results cache.

Abstract: Computer-readable media, methods, and systems are disclosed for linear interval-based dynamic range partitioning in one or more database systems. A request is received by a database management system to insert a new row into a partitioned database table. The partitioned database table may include a plurality of existing partitions and a partition others partition. Based on determining that the new row should be inserted into the partition others partition a series of steps are performed. First, one or more new partitions are added to the partitioned database table. Then, the new row is inserted into the one of the one or more new partitions in the partitioned database table.

Abstract: Computer-readable media, methods, and systems are disclosed for utilizing partition-based locking mechanisms to improve execution of overlapping data definition language (DDL) and data manipulation language (DML) operations on a partitioned database table. A first node receives a DML statement associated with a first transaction. The first node acquires a intent exclusive lock on table metadata. A second node receives a DDL statement associated with a second transaction and acquires an exclusive metadata lock on the partitioned table metadata. Next, an intent exclusive lock is acquired for the relevant partition table data on the second node and an exclusive lock on table metadata on the second node. The second transaction waits for the DML operation of the first transaction to complete. Then the first transaction is committed. Finally exclusive locks are acquired on table data and metadata and the second transaction is executed and committed.

Abstract: A double-deck rail vehicle and a vehicle body thereof are provided. An underframe (11) of the vehicle body comprises a lower-layer underframe (111), end underframes (112, 115), sealing plates (114, 116), and side underframes (118, 119); wherein the lower-layer underframe is provided with an underframe middle beam (1111); the end underframe is fixedly connected to the underframe middle beam by means of reinforcement middle beams (113, 117); the sealing plate is fixedly connected between the end underframe and the lower-layer underframe; and the side underframe comprises side beams (1181, 1191) of the side underframe that are integrated, and the side underframe is fixedly connected to the end underframe by means of the side beams of the side underframe. The vehicle body supplements the reinforcement middle beams capable of increasing the connection strength between the end underframe and the lower-layer underframe, and uses the integrated side beams of the side underframe.

Abstract: Computer-readable media, methods, and systems are disclosed for database table partition pruning based on statistical information associated with non-partition columns. A tree partition specification is received defining partitions for a plurality of computed column statistics. Respective partitions are created for the plurality of computed column statistics based on the tree partition specification. A request is received to compute statistics for a plurality of columns of the plurality of computed column statistics to result in a plurality of computed column statistics. In response to determining that one or more modifications have been made to the partitioned database, the plurality of computed column statistics is marked as invalid. The computed column statistics are refreshed in response to modifications of the partitioned table. Thereafter, the statistics are marked as valid. Unnecessary table partitions are pruned based on the statistics, and the associated query is executed.

Abstract: Computer-readable media, methods, and systems are disclosed for linear interval-based dynamic range partitioning in one or more database systems. A request is received by a database management system to insert a new row into a partitioned database table. The partitioned database table may include a plurality of existing partitions and a partition others partition. Based on determining that the new row should be inserted into the partition others partition a series of steps are performed. First, one or more new partitions are added to the partitioned database table. Then, the new row is inserted into the one of the one or more new partitions in the partitioned database table.

Abstract: Computer-readable media, methods, and systems are disclosed for database table partition pruning based on statistical information associated with non-partition columns. A tree partition specification is received defining partitions for a plurality of computed column statistics. Respective partitions are created for the plurality of computed column statistics based on the tree partition specification. A request is received to compute statistics for a plurality of columns of the plurality of computed column statistics to result in a plurality of computed column statistics. In response to determining that one or more modifications have been made to the partitioned database, the plurality of computed column statistics is marked as invalid. The computed column statistics are refreshed in response to modifications of the partitioned table. Thereafter, the statistics are marked as valid. Unnecessary table partitions are pruned based on the statistics, and the associated query is executed.

Abstract: Computer-readable media, methods, and systems are disclosed for utilizing partition-based locking mechanisms to improve execution of overlapping data definition language (DDL) and data manipulation language (DML) operations on a partitioned database table. A first node receives a DML statement associated with a first transaction. The first node acquires a intent exclusive lock on table metadata. A second node receives a DDL statement associated with a second transaction and acquires an exclusive metadata lock on the partitioned table metadata. Next, an intent exclusive lock is acquired for the relevant partition table data on the second node and an exclusive lock on table metadata on the second node. The second transaction waits for the DML operation of the first transaction to complete. Then the first transaction is committed. Finally exclusive locks are acquired on table data and metadata and the second transaction is executed and committed.

Abstract: A method may include generating a database table to include a first partition having a first range and a dynamic partition associated with an undefined range of a specified length. A record may be inserted into the database table. In response to one or more values of the record being outside of the first range of the first partition, a second partition having a second range of the specified length that includes the one or more values of the record may be generated. The record may be stored in the second partition. Moreover, a query on the database table may be executed by the first partition and/or the second partition of the database table. Related systems and articles of manufacture are also provided.

Abstract: A method for processing a query may include evaluating a query on a database table to identify a time based function included in the query. One or more partitions of the database table may be pruned from the query based at least on the partitions being associated with a first time range that does not overlap with a second time range associated with the time based function. An execution plan for the query may be generated to include a sequence of operations that avoids accessing the one or more partitions pruned from the query. The query may be executed based at least on the execution plan by at least accessing a second partition of the database table but not the first partition of the database table pruned from the query. Related systems and articles of manufacture are also provided.

Abstract: A method may include generating a database table to include a first partition having a first range and a dynamic partition associated with an undefined range of a specified length. A record may be inserted into the database table. In response to one or more values of the record being outside of the first range of the first partition, a second partition having a second range of the specified length that includes the one or more values of the record may be generated. The record may be stored in the second partition. Moreover, a query on the database table may be executed by the first partition and/or the second partition of the database table. Related systems and articles of manufacture are also provided.

Abstract: A double-deck rail vehicle and a vehicle body thereof are provided. An underframe (11) of the vehicle body comprises a lower-layer underframe (111), end underframes (112, 115), sealing plates (114, 116), and side underframes (118, 119); wherein the lower-layer underframe is provided with an underframe middle beam (1111); the end underframe is fixedly connected to the underframe middle beam by means of reinforcement middle beams (113, 117); the sealing plate is fixedly connected between the end underframe and the lower-layer underframe; and the side underframe comprises side beams (1181, 1191) of the side underframe that are integrated, and the side underframe is fixedly connected to the end underframe by means of the side beams of the side underframe. The vehicle body supplements the reinforcement middle beams capable of increasing the connection strength between the end underframe and the lower-layer underframe, and uses the integrated side beams of the side underframe.

Abstract: Disclosed are heterocyclic compounds of the formula and the pharmaceutically acceptable salts thereof wherein the variables A, V, Y, J, E, X, T, G, Q, W, Z, b, n and m are defined herein. These compounds are highly selective agonists, antagonists or inverse agonists for GABAA brain receptors or prodrugs of agonists, antagonists or inverse agonists for GABAA brain receptor.

Abstract: Disclosed are heterocyclic compounds of the formula 1

Abstract: Disclosed are heterocyclic compounds of the formula and the pharmaceutically acceptable salts thereof wherein the variables A, V, Y, J, E, X, T, G, Q, W, Z, b, n and m are defined herein. These compounds are highly selective agonists, antagonists or inverse agonists for GABAA brain receptors or prodrugs of agonists, antagonists or inverse agonists for GABAA brain receptor.

Abstract: Disclosed are heterocyclic compounds of the formula 1