摘要:
A method and apparatus for debugging the source code of a computer program are provided. A debugging system typically provides step into and step over commands that allow for the stepwise execution of a computer program. Embodiments of the invention allow users to specify lines of source code at which to override a step over command and instead perform a step into command. Further, a debugging system configured according to the present invention may analyze user activity or the program being debugged to identify locations in the source code where a programmer may prefer to step into a function call, rather than perform a step over operation.
摘要:
A query processor includes a HAVING clause processing mechanism that processes the HAVING clause in a query when generating the intermediate results, instead of generating the intermediate results without regard to the HAVING clause, then applying the HAVING clause to the intermediate results. As a result, the size of the intermediate results may be significantly reduced, and effort is not wasted in placing data into the intermediate results in one step that would be removed were the HAVING clause processed separately.
摘要:
An apparatus and method to optimize a query access plan in a computer database system. In preferred embodiments, the query optimizer determines the query can be optimized and generates for the query an optimized access plan that eliminates records defined by a Where clause and one or more ordering criteria prior to ordering the records (sorting or grouping) and then returning a first n rows.
摘要:
A master table and one or more slave tables are linked together by different referential integrity constraints. A database engine maintains a separate data structure that includes information about which slave tables include corresponding records that may be affected by a constraint. Accordingly, when an operation is performed on the master table, the data structure is referenced to determine which slave tables has records which are affected as well. The data structure may be a bitmap, an encoded vector index, or separate fields within the master database. As a result of this data structure, unnecessary I/O operations are avoided involving slave tables without a corresponding record.
摘要:
An apparatus and method optimize a UNION-type query, where the query has common components on both sides of the UNION-type operator. The UNION-type expression is analyzed to determine if the expression can be optimized, and if so, common portions on both sides of the UNION-type expression are extracted and the expression is reformulated so the common portions on both sides of the union expression are only run one time.
摘要:
A computer system, program product and method debug an object-oriented computer program by tracking the creation of objects by a plurality of creators (e.g., constructor methods) of a selected class. A user need not separately track each creator. Instead, a debugger identifies each creator and associates breakpoints with all or a user-specified subset of creators to facilitate tracking. Any of the breakpoints may then trigger a halting of execution during debugging. Moreover, in some instances it may be desirable to track the number of creations by all or the subset of the creators for the selected class during program execution until a user-specified condition is satisfied, whereupon program execution is terminated and debugging information is provided to the user.
摘要:
A database engine and optimizer framework includes a decoder to identify and process SQL queries or statements that reference a UDF before they are executed. Once such a statement is detected, the decoder determines if the UDF is capable of being merged into an SQL statement and, if so, performs such a merge. In some embodiments, the decoder may not use a pre-cached version of the UDF but, instead, may include a component that locates and retrieves the latest version of the UDF for use when performing the merge. Also, for UDFs that cannot easily be merged into an SQL statement, the decoder may not merge the UDF into an SQL statement but may allow the optimizer and execution engine to retrieve and execute the UDF in the usual manner.