Abstract: A mechanism is described for constructing work granules, where the work granules are constructed independently of whether two or more of the work granules are assigned to operate on a logical storage unit that contains a portion of the same row. A database system maintains transaction control data for data blocks in a manner that avoids self-deadlocks for slaves that follow a row collision protocol. A row collision protocol is a set of rules or steps that slaves follow to ensure that only one subtransaction in a distributed transaction updates a spanning row. Thus, for a particular spanning row, a single subtransaction modifies all the row pieces of the spanning row in any data block containing any row pieces of the spanning row. Consequently, a given data block may be affected by multiple subtransactions in a distributed transaction, one subtransaction affecting a row piece in the data block, another subtransaction affecting other rows in the data block.

Abstract: Disclosed is a method and mechanism for duration-based management of temporary large objects (“LOBs”) in a database system. According to one aspect, temporary LOBs are associated with a duration having a lifespan that corresponds to the lifespan of the temporary LOBs. When the duration ends, the associated temporary LOBs, and any resources allocated to the temporary LOBs, are automatically released. According to another aspect, multiple durations of varying, and possibly overlapping lifespans, can exist in the database system. According to yet another aspect, a tree of durations can be created having multiple ancestor and descendant durations.

Abstract: Disclosed is a method and mechanism for duration-based management of temporary large objects (“LOBs”) in a database system. According to one aspect, temporary LOBs are associated with a duration having a lifespan that corresponds to the lifespan of the temporary LOBs. When the duration ends, the associated temporary LOBs, and any resources allocated to the temporary LOBs, are automatically released. According to another aspect multiple durations of varying, and possibly overlapping lifespans, can exist in the database system. According to yet another aspect, a tree of durations can be created having multiple ancestor and descendant durations.