International Business Machines Corporation

Jian Wei Zhang

Xin Yang

Shuo Li

Ke Wei Wei

Li Ping Yang

Ping Liang

Shu Hua Liu

Zhong Su

Jian Ye Chen

Xiang Sean Zhou

Sheng Hua Bao

You-Chin Gene Fuh

Wei Jiang

Heng Liu

Jing Zhou

A computer-implemented method includes receiving a batch processing job. The method identifies multiple access paths for the batch processing job. The method determines one or more runtime costs for each of the multiple access paths. The method determines whether the batch processing job includes comparable access paths. The method responds to the batch processing job not including comparable access paths by receiving a query and selecting a desired access, based on the one or more runtime costs. The method responds to the batch processing job including comparable access paths by determining one or more context costs for each of the one or more access paths, receiving a query, identifying a context for the query, and selecting a desired access path for the query. The desired access path is based on the one or more runtime costs, the one or more context costs, and the context for the query.

Context based access path selection

A method to optimize a database is provided. A processor determines a frequency of search for a plurality of columns in a table. A processor determines a length of the plurality of columns. A processor determines a rank for the plurality of columns based, at least in part, on both the frequency of search and the length of the plurality of columns. A processor generates a first set of combinations of the plurality of columns. A processor determines an optimization of the first set of combinations of the plurality of columns. A processor selects an optimal combination of the first set of combinations, wherein the optimization of the optimal combination is greater than the optimization for all other combinations in the first set of combinations. A processor moves the plurality of columns excluded from the optimal combination.

Data table performance optimization

Embodiments of the present invention provide a method, computer program product, and computer system for masking indexes. The method may include masking the index if the index contention exceeds a defined threshold. The method may also include configuring the mask type for the index to insert the index without masking. In response to determining that the mask type for the index is configured to insert the index without masking, the index is masked according to a set of rules.

Index masking based on insert contention ratio

A computer system to optimize a database is provided. A processor determines a frequency of search for a plurality of columns in a table. A processor determines a length of the plurality of columns. A processor determines a rank for the plurality of columns based, at least in part, on both the frequency of search and the length of the plurality of columns. A processor generates a first set of combinations of the plurality of columns. A processor determines an optimization of the first set of combinations of the plurality of columns. A processor selects an optimal combination of the first set of combinations, wherein the optimization of the optimal combination is greater than the optimization for all other combinations in the first set of combinations. A processor moves the plurality of columns excluded from the optimal combination.

A computer program product to optimize a database is provided. A processor determines a frequency of search for a plurality of columns in a table. A processor determines a length of the plurality of columns. A processor determines a rank for the plurality of columns based, at least in part, on both the frequency of search and the length of the plurality of columns. A processor generates a first set of combinations of the plurality of columns. A processor determines an optimization of the first set of combinations of the plurality of columns. A processor selects an optimal combination of the first set of combinations, wherein the optimization of the optimal combination is greater than the optimization for all other combinations in the first set of combinations. A processor moves the plurality of columns excluded from the optimal combination.

Managing free space in a relational database. A data statistics history for the relational database is received, including a distribution of index key columns for a clustering index. Based on the data statistics history, increasing index key columns are identified. A rate of increase of the increasing index key columns is measured. Based on the measured rate of increase and on an estimate of database reorganization frequency, free space for the increasing index key columns is reserved.

Free space management in databases

A terminal that includes a transmitter, a receiver, and an updater. The transmitter is configured to broadcast a first data packet in response to the terminal being connected to a local area network (LAN). The first data packet includes at least one of an Internet protocol (IP) address and a media access control (MAC) address of the terminal as well as a domain name of the terminal. The receiver is configured to receive a second data packet broadcasted by another terminal on the LAN. The second data packet includes at least one of an IP address and a MAC address of the other terminal as well as a domain name of the other terminal. The updater is configured to update a domain name system (DNS) configuration in the terminal based on the second data packet received by the receiver.

Providing a virtual domain name system (DNS) in a local area network (LAN)

Embodiments of the invention relate to organizing data records in a relational database. An aspect of the invention includes creating index items for a plurality of data records. Each index item includes a counter and the creating results in a plurality of counters. The numerical values of counters in corresponding index items are updated for data records in the plurality of data records that are subjected to random access. The plurality of data records are reorganized based upon the numerical values of the plurality of counters.

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Beijing, China

Jian Wei Zhang