Sap Se

Anupam Mukherjee

Amarnadh Sai Eluri

Vimal Chandran Satheesh

Mihnea Andrei

Andreas Tonder

Disclosed herein are system, method, and computer program product embodiments for managing timestamp information in memory systems. In an embodiment, an infrastructure may utilize a controller to manage sparse timestamp blocks. These sparse timestamp blocks may manage timestamp information in a persistent memory structure. Controllermay utilize a transient timestamp accessor to map the timestamp information for faster hash lookups. Controllermay also utilize a garbage collection map as a bitmap to further save processing steps. Controllermay utilize the sparse timestamp blocks, transient timestamp accessor, and garbage collection map to efficiently store timestamp data and to quickly retrieve the stored timestamp data.

Sparse infrastructure for tracking ad-hoc operation timestamps

A method may include iterating through at least a portion of a table stored in a database by identifying a timestamp block associated with a range of rows forming the portion of the table. In response to determining that the timestamp block is a sparse timestamp block storing timestamps associated with only some of the rows in the first range of rows, generating a bitmap. Each of the binary values in the bitmap may correspond one of the rows in the range of rows. Moreover, each of the binary values in the bitmap may indicate whether the timestamp block includes a timestamp associated with a corresponding row from the range of rows. Iterating through the range of rows may include accessing, based on the bitmap, the timestamp block to read or write timestamps of transaction affecting the rows in the range of rows.

Timestamp block iterator

A method may include performing a transaction on a row in a table stored in a database. In response to performing the transaction, a first timestamp block associated with a range of rows including the row may be retrieved. In response to determining that the first timestamp block is a sparse timestamp block that has reached maximum capacity, a second timestamp block may be allocated for storing the timestamp associated with the transaction. The sparse timestamp block may be allocated with sufficient storage space for storing some but not all of the timestamps associated with the range of rows. By contrast, the second timestamp block may be a dense timestamp block allocated with sufficient storage space for storing all of the timestamps associated with the range of rows. The timestamp associated with the transaction may be stored in the second timestamp block.

Adaptive timestamp access controller

Provided is a system and method for improving memory management in a database. In one example, the method may include receiving a request to store a data object within a database, determining a category type associated with the data object from among a plurality of category types based on an attribute of the data object, and storing the data object via a memory pool corresponding to the determined category from among a plurality of memory pools corresponding to the plurality of respective categories, where the storing comprises allocating a first category type of data object to a first memory pool locked to main memory and allocating a second category type of data object to a second memory pool that is swapped out to disk over time. The locked memory pool can ensure that more important data items remain available even when they are the least recently used.

Growing community of inventors

Palo Alto, CA, United States of America

Anupam Mukherjee