摘要:
The invention provides for verifying correctness of a database system. A SQL instruction is received and access paths of the received SQL instruction are extended. The SQL instruction is executed by using the extended access paths, and the correctness of the database system is verified according to results of executing the SQL instruction. With the method and system of the invention, the object of verifying correctness of a database system by automatically extending access paths of SQL statement may be achieved, and the object of verifying correctness of a database system scientifically, effectively and purposefully based on ratio of error or defect present in database itself due to various data manipulation approaches (different values of access path elements) may also be achieved.
摘要:
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.
摘要:
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.
摘要:
Embodiments of the invention relate to database large object (LOB) reorganization. An aspect of the invention includes calculating an activity of an inline LOB. The length of an inline LOB is redefined according to the activity of the inline LOB. LOB reorganization is performed based on the redefined length of the inline LOB.
摘要:
Embodiments of the present invention relate to dynamically merging executable structures in a database system. In one embodiment, there is provided a method of dynamically merging executable structures in a database system that includes, in response to a query to the database system, extracting a stem and a branch of a query statement. The query statement includes query conditions, and the branch includes at least a subset of the query conditions. An executable structure of the stem is obtained from a cache of the database system, and an executable structure of the branch is generated. The executable structure of the stem and the executable structure of the branch are merged into a runtime executable structure.
摘要:
The invention provides a method for verifying correctness of a database system, comprising: receiving SQL instruction; extending access paths of the received SQL instruction; executing the SQL instruction by using the extended access paths; and verifying correctness of the database system according to result of executing the SQL instruction. With the method and system of the invention, the object of verifying correctness of a database system by automatically extending access paths of SQL statement may be achieved, and the object of verifying correctness of a database system scientifically, effectively and purposefully based on ratio of error or defect present in database itself due to various data manipulation approaches (different values of access path elements) may also be achieved.
摘要:
Embodiments of the invention relate to database large object (LOB) reorganization. An aspect of the invention includes calculating an activity of an inline LOB. The length of an inline LOB is redefined according to the activity of the inline LOB. LOB reorganization is performed based on the redefined length of the inline LOB.
摘要:
A method and system for mitigating distortion in coherent single-ended photo-detection is disclosed. The methodology comprises: receiving an optical signal carried on an optical transmission medium and coherently detecting the received optical signal to produce a digitized signal; estimating a time-dependent random variable introducing distortion to the coherently detected signal; and subtracting the distortion from digitized signal to produce a distortion mitigated output signal.