A method and apparatus for processing count queries in a database system is provided. The database server determines whether it is possible for the target data specified in a count query to contain null values. If the target data cannot contain null values, the count query is converted into a count star query. Count star queries are executed by counting the number of records that store the target data without actually reading and evaluating the target data. If an index for the table that stores the target data exists, then the number of records are counted without accessing the table itself by counting record identifiers in the index. If the index is a bitmap index, the number of bits that are set in bitmaps from the index are counted without actually generating record identifiers from the bitmaps. Many processes are used to generate intermediate count values from the bitmaps. The intermediate count values are summed to produce a total count value. For count queries that contain group by clauses, intermediate count values are generated for each distinct key value. The intermediate count values are summed to produce a total count value for each distinct key value.
A tree system diagram output method of correlating a plurality of objects and outputting the plurality of objects as a tree system diagram includes the steps of: (a) storing, in a first storing part, an identifier specific to each of the plurality of objects written on a first worksheet; (b) selecting at least one object among the plurality of objects written on the first worksheet; (c) pasting the object selected in the step (b) to a second worksheet; and (d) changing the identifier of the object to be pasted in the step (c) to a second identifier.
A linker is described and the method of forming an executable program from object code modules using the linker. The linker uses a linker control language in the form of an ordered sequence of relaxation instructions. The relaxation instructions include a jump relaxation instruction which specifies the instruction count of the relaxation instruction which is subsequently read. In this way, more flexibility can be provided for linkers.
An apparatus and method to significantly improve performance of SQL function processing through the use of an encoded vector index (EVI). An EVI provides the data necessary to count the number of records in a database that match criteria provided by a SQL function. The resulting count can then be used to determine, from among two or more candidate approaches, an approach to use in processing an SQL function. By processing the EVI symbol table in lieu of more traditional database indexes, and/or in lieu of the database table itself, statistics for SQL functions are generated significantly faster.
A tree system diagram output method of correlating a plurality of objects and outputting the plurality of objects as a tree system diagram includes the steps of: (a) storing, in a first storing part, an identifier specific to each of the plurality of objects written on a first worksheet; (b) selecting at least one object among the plurality of objects written on the first worksheet; (c) pasting the object selected in the step (b) to a second worksheet; and (d) changing the identifier of the object to be pasted in the step (c) to a second identifier.
A relational mapper supports the storage of objects from an object oriented environment in one or more relational databases. The relational mapper generates tables in a relational data store for abstract class types, and it generates a mapping, in any predetermined relationship, to map at least one member of an object to a table for the class type in the relational data store. The relational mapper maps members of a class type to members of a data source. A storage type map is generated to map the data source members of the data source to columns of the relational database table for the class type. The relational mapper is bidirectional such that the relational mapper maps data from a relational database to create objects in accordance with a type system of an object oriented environment. The relational mapper generates metadata to describe the object such that the object, created from the relational database, is a full fledged object of the object oriented system.
