Abstract: An improved method to dramatically reduce the time required to reorganize DB2 tablespaces and index files by not utilizing conventional sort techniques. Viewing access is allowed during the reorganization process by setting the files to read only status. The process is basically non-destructive, allowing a prompt return to the original state, and is checkpointed, allowing restarting at selected intervals. Briefly, the original table and indices are considered as A files and read into memory. New row IDs or RIDs are developed using a non-sorting technique so that the proper order of the data is developed. After the new RIDs have been developed, both the clustering index and the row data are read out of memory and written to a new table and clustering index files in the proper order as B files. All of the table files are then stopped to allow exclusive access. Next, a series of AMS statements are built to do the renaming operations.

Abstract: An improved method to dramatically reduce the time required to reorganize DB2 tablespaces and index files by not utilizing conventional sort techniques. Viewing access is allowed during the reorganization process by setting the files to read only status. The process is basically non-destructive, allowing a prompt return to the original state, and is checkpointed, allowing restarting at selected intervals. Briefly, the original table and indices are considered as A files and read into memory. New row IDs or RIDs are developed using a non-sorting technique so that the proper order of the data is developed. After the new RIDs have been developed, both the clustering index and the row data are read out of memory and written to a new table and clustering index files in the proper order as B files. Then any remaining non-clustering indices are reorganized using non-sorting techniques in a similar fashion.

Abstract: A method for reorganizing database index files without performing a conventional sort operation. The index file uses a balanced tree structure, with the logical order of the entries in each page being maintained by the database program. In the reorganizing method the logical order of the leaf pages is determined. A logical order buffer is developed which correlates the logical order to the physical order. This buffer is transposed to a physical order to logical order buffer. A large buffer is set aside in memory and the index file is read sequentially. As each physical page is read, it is placed in its logical position in the large memory buffer. When the large buffer is filled, the pages are sequentially written to a new index file, with the various tree pages being developed in the fly. When the writing operation is completed, the old index file is removed and the new, ordered index file is used.