Browse Prior Art Database

Building of All Data Objects Prior to Threaded Code Generation

IP.com Disclosure Number: IPCOM000037581D
Original Publication Date: 1989-Apr-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Coyle, DJ: AUTHOR [+3]

Abstract

Disclosed is an algorithm for building all data objects that will be needed to correctly interpret a given query. These data objects are used at thread building time to build the threaded code that is used to interpret the query.

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Building of All Data Objects Prior to Threaded Code Generation

Disclosed is an algorithm for building all data objects that will be needed to correctly interpret a given query. These data objects are used at thread building time to build the threaded code that is used to interpret the query.

The basic structures used in a typical query: tables, columns, indexes, column functions, sorts, joins, etc., all have associated object structures that need to be built in order to implement the query. The disclosed algorithm uses the referent table structures that have already been created to determine which data objects need to be created. The query block structures are traversed in a query block by query block progression until all query blocks needed to implement the specified query have been processed. While traversing a particular query block the plan entries associated with that query block are traversed to determine what type of object structures are needed to completely describe each particular plan entry. Based on what type of plan entry is being processed any number of data object structures will be created within the access section. For instance if a plan involves a table, then a "Table Object" structure is built to describe this table. In addition "Column Object" structures for each column of that particular table that is used in the query are built to describe the column entries. The offsets within the access section at which these object structures are located...