Aggregating modifications to a database for journal replay
Aggregating database entry modifications for replay of database changes includes: inserting, in a journal modification table, of database entry modifications, where each database entry is associated with a relative record number; and, for each relative record number: aggregating, in the journal modification table, a plurality of the modifications into a single modification.
1. A method of aggregating database entry modifications for replay of database changes, the method comprising:
inserting, by at least one computer, in a journal modification table, a plurality of database entry modifications, each database entry associated with a relative record number, the plurality of database entry modifications comprising a plurality of entry insertion operations;
aggregating, by the at least one computer, in the journal modification table, two or more of the database entry modifications corresponding to a same relative record number by, for each relative record number, identifying, from one or more modifications of each field of a database entry, a last modification of more than one field of the database entry associated with the same relative record number and creating, for each relative record number, a single modification operation to effect each of the identified last modifications of the fields of the database entry;
identifying, by the at least one computer, from the entry insertion operations, a field common amongst the entry insertion operations;
identifying, by the at least one computer, entry insertion operations having a matching value in the identified field; and
grouping, by the at least one computer, the entry insertion operations having the matching value in the identified field by reassigning, in incremental order, the relative record number of each of the entry insertion operations having the matching value in the identified field.
2. The method of claim 1 further comprising ordering, in the journal modification table, the database entry modifications by relative record number.
3. The method of claim 1 further comprising removing from the journal modification table, for each aggregated database entry modification, all database entry modifications comprising the aggregated database entry modification.
4. The method of claim 1 wherein inserting a plurality of database entry modifications in the journal modification table is carried out in parallel with tracking the plurality of database entry modifications in a journal.
5. The method of claim 1 wherein inserting a plurality of database entry modifications in the journal modification table is carried out responsive to parsing a journal that includes the plurality of database entry modifications.
6. The method of claim 1 further comprising prior to aggregating the plurality of database entry modifications into a single modification operation, selecting the plurality of database entry modifications in dependence upon predefined criteria.