International Business Machines Corporation

Di Jin

Min Fang

Li Fei Zheng

Shu Wang

Nigel G Slinger

Wen Jie Zhu

Zhen Yu Shi

Zhenyu Shi

Ye Wy Wang

Bart J L Steegmans

Mei Zhen Cao

Embodiments of the present disclosure relate to a method, system, and computer program product for block level lock on a data table. According to the method, in response to first transactional processing to be applied on a data table, one or more processors determine that first target data to be accessed during execution of the first transactional processing is comprised in a continuous range of data in the data table. One or more processors determine whether a block lock is available for locking the continuous range of data for the first transactional processing. In accordance with a determination that the block lock is available, one or more processors grant the first transactional processing with the block lock, the block lock being associated with lock information indicating the continuous range of data.

Block level lock on data table

Embodiments of the present invention disclose a method, computer program product, and system for inserting one or more records into a database table. An insert request for inserting a new record to a database table is received, wherein the new record includes at least one key field. a partial identity of at least one record matching the at least one key field of the new record is searched for. A partial identity is assigned to the new record based on a result of the searching.

Record insertion by generating unique index bases

Data records may be managed in a relational database by monitoring, a record length for a first data record in a page of memory, an amount of free space in the page, and a page length. In response to receiving an operator command to replace the first data record with a second data record, a database management system may determine whether an estimated record length of a compressed second data record is outside of the amount of free space in the page. In response to determining the estimated record length of a compressed second data record is outside of the amount of free space in the page, the database management system may determine whether an estimated length of a compressed page is outside of the page length. In response to determining the estimated length of a compressed page is within the page length, the page may be compressed.

Managing data records

An approach for index B-tree page creation associated with linear sequential insertions in database management systems (DBMS). A linear pre-splitter receives a current index leaf page for linear sequential insertion. The linear pre-splitter asynchronously creates index leaf pages where the current index leaf page is in a predetermined position at least one page away from a last index leaf page. The linear pre-splitter updates index leaf page position identifiers associated with the index leaf pages where the index leaf page position identifiers link the index leaf pages and the last index leaf page and the linear pre-splitter inserts index leaf page identifiers and index key metadata associated with each of the index leaf pages into index non-leaf pages.

Index B-tree maintenance for linear sequential insertion

Allocating free space in a database table. Statistics associated with records in a database are received, including an average record byte size for records stored in the database table. A primary free space byte size for record updates is determined, including comparing a preliminary free space byte size to the average record byte size and a byte size of a record subjected to a database operation. Based on the primary free space byte size, free space at the page level of the database table is allocated.

Allocating free space in a database

Embodiments of the present invention provide computer-implemented methods, computer systems and computer program products. According to one embodiment of the present invention, an index of a database is obtained, where the index includes at least one node associated with index information of at least one old data entry that has been deleted from the database, and the node is marked as invalid. Then, a node included in the index is selected based on a key value in index information of a new data entry in response to the new data entry being inserted into the database. Next, the selected node is updated with the index information of the new data entry.

Index management

As disclosed herein a method, executed by a computer, includes storing, by one or more processors, entries associated with an index to a first buffer of at least two buffers allocated to the index, and moving, by a batch operation, by one or more processors, entries in the first buffer into an index page for the index in response to an entry movement condition being met. The method further includes storing, by one or more processors, new entries associated with the index to another buffer of the at least two buffers while moving the entries in the first buffer. A computer program product corresponding to the above method is also disclosed herein. A computer program product and computer system corresponding to the above method are also disclosed herein.

A computer-implemented method for recovering data and concurrently rebuilding indexes for the recovered data in a database for a system configured to store fewer than all indexes in backup files may include copying data from one or more database files and storing the copied data to one or more backup files. A recovery manager executing on a processor may read the copied data from the one or more backup files and write the copied data to the one or more database files, wherein the data is recovered to the one or more database files. In response to the reading, an index manager executing on the processor may initiate a rebuilding of one or more indexes for the copied data at substantially the same time as the reading of the copied data.

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Beijing, China

Di Jin