Patent ID: 6961729

Claim:
A computer implemented method of modifying data in a database system, the method comprising the steps of: constructing work granules that manipulate rows in a manner that groups the rows within said work granules according to logical storage units that contain the rows; and during execution by an entity of a particular work granule that involves manipulation operations for rows in a logical storage unit: causing said entity to perform said manipulation operation for rows completely contained in said logical storage unit; determining that a set of spanning rows that are partially contained in said logical storage unit satisfy a particular condition that relates to which portion of each spanning row of said set of spanning rows resides in said logical storage unit; and causing said entity to perform said manipulation operations for all pieces of all spanning rows in said set of spanning rows based on the step of determining, and wherein said work granules are executed as part of a transaction that includes a first subtransaction and a second subtransaction, wherein a first work granule is executed as part of said first subtransaction and a second work granule is executed as part of said second subtransaction.