Sap Se

Changgyoo Park

Juchang Lee

Ivan Schreter

Mihnea Andrei

Norman May

Hannes Jakschitsch

Yongjae Chuh

Thomas Seufert

Thorsten Glebe

Michael Muehle

Eunsang Kim

Byunghoon Kim

A system includes reception of a request for recovery of a database to a recovery time, determination of a recovery logical timestamp corresponding to the recovery time, identification of database log records associated with a logical timestamp preceding the recovery logical timestamp, application of the identified database log records to the database sequentially according to log sequence number, identification, after applying the identified database log records, of one or more open transactions on the database, identification of a first one or more of the one or more open transactions which are associated with a commit log record associated with a logical timestamp preceding the recovery logical timestamp, and, in response to identification of the first one or more of the one or more open transactions, committing of the first one or more of the one or more open transactions.

Database recovery based on logical timestamp

Implementations of the present disclosure include associating a first transaction executed within a database system with a first transaction control block (TCB) index, setting a status of the first transaction to active and a lock status of the first transaction to holding in response to a first set of locks being established for the first transaction, the first set of locks including one or more locks that each inhibit access to a respective resource within the database system, providing a lock table that records, for a set of locks within the database system, a set of lock owners including one or more transactions identified based on respective TCB indexes and a wait queue, and determining that the first transaction has completed, and in response setting the status of the first transaction to indicate completion of the transaction and the lock status of the first transaction to released.

Time-efficient lock release in database systems

Disclosed herein are system, method, and computer program product embodiments for efficiently providing transaction-consistent snapshots of data stored in or associated with a database stored within a database management system. An embodiment operates by receiving, at a source database, an update request to update a table at the source database and transmitting a message to a cache node to invalidate a copy of a table time stamp associated with the table, where the copy of the table time stamp is stored at the cache node. The embodiment continues by updating the table at the source database based on the update request.

Transactional cache invalidation for inter-node caching

Disclosed herein are systems, methods, and computer program products for providing transaction-consistent snapshots of data stored in or associated with a database. An embodiment operates by receiving, at a source database, an update request to update data associated with a table stored at the source database, and modifying a value of a modification-in-progress data structure corresponding to the table to indicate that a modification is in progress for the table. The embodiment includes updating a value of a commit identification counter and a table time stamp associated with the table to indicate that cached data having a time stamp older than the updated time stamp are invalid. The embodiment further includes modifying the value of the modification-in-progress counter to indicate completion of table modification.

Atomic visibility switch for transactional cache invalidation

A plurality of transactions is handled in a database. Each transaction includes a plurality of operations on at least one record in the database with at least two of the transactions being handled concurrently. Thereafter, a temporary timestamp is assigned to each record. The temporary timestamp are based, at least in part, on the corresponding transaction. Further, a final timestamp is assigned to each record with a commit operation. It can later be determined, using a visibility function and based on the assigned temporary timestamps and final timestamps, which of the records are visible in a consistent view for a first transaction. Based on such determination, access can be provided to those records determined to be visible to be accessed to the first transaction.

Database system with transaction control block index

A plurality of transactions are handled in a database. Each transaction comprises a plurality of operations on at least one record in the database with at least two of the transactions being handled concurrently. Thereafter, a temporary timestamp is assigned to each record that is based, at least in part, on the corresponding transaction. A first transaction among the plurality of transactions is subsequently committed. Afterwards, re-stamping of at least one commit timestamp modified by the first transaction is delegated. Related apparatus, systems, techniques and articles are also described.

Delegation of database post-commit processing

A database upon opening each of at least one cursor for a transaction, assigns each statement forming part of a transaction a statement sequence number (SSN) involving at least one row of the database. Thereafter, temporary timestamps are assigned to the at least one row using a transaction identifier and the corresponding SSN. Further, active cursors are monitored such that a final timestamp is prevented from being associated with each row until it has no remaining cursors. Related apparatus, systems, techniques and articles are also described.

Growing community of inventors

Seoul, South Korea

Changgyoo Park