Sap Se

Sybase, Inc.

Sybass, Inc.

Prasanta Ghosh

Girish Vaitheeswaran

Colin Florendo

Simhachala Sasikanth Gottapu

Sarika Iyer

Prateek Agarwal

Vadiraja Bhatt

Mihnea Andrei

Norman May

Praveen Vegulla

Chaitanya Gottipati

Fei Zhou

Srikanth Sampath

Nirvik Basak

Souvik Pal

Taghi Fatemi

Amit Saonerkar

Disclosed herein are system, method, and computer program product embodiments for adaptive caching for hybrid columnar databases with heterogeneous page sizes. An embodiment operates by scanning one or more pools comprising one or more pages of the same size in a buffer cache. The embodiment determines an increment of a reuse rate for the pools in the buffer cache within a time interval. The embodiment determines a cumulative reuse rate that is the sum of the increments of the reuse rate over several time intervals. The embodiment determines a gliding average reuse rate of the cumulative reuse rate over several time intervals. The embodiment compares the average reuse rates of the plurality of the pools to a threshold to dynamically determine whether a pool should reuse memory from the existing pages of the same pool or rebalance memory from one or more victim pools.

Adaptive caching for hybrid columnar databases with heterogeneous page sizes

Disclosed herein are system, method, and computer program product embodiments for adaptive caching for hybrid columnar databases with heterogeneous page sizes. An embodiment operates by receiving a request to load a new page of memory from a disk in a buffer cache. The embodiment scans one or more pools comprising one or more pages of the same size in a buffer cache. The embodiment determines an increment of a reuse rate for the pools in the buffer cache within a time interval. The embodiment determines a cumulative reuse rate that is the sum of the increments of the reuse rate over several time intervals. The embodiment determines a gliding average reuse rate of the cumulative reuse rate over several time intervals. The embodiment compares the average reuse rates of the plurality of the pools to a threshold to dynamically determine whether a pool should reuse memory from the existing pages of the same pool or rebalance memory from one or more victim pools.

System, method, and various embodiments for providing a metadata based memory management system are described herein. An embodiment operates by determining metadata of a table of a database indicating whether data of the table is to be stored in memory or disk storage, wherein the table comprises a plurality of columns and a plurality of rows. A first column of the table is identified. A hierarchy of the metadata for the table including a column value, partition value, and table value is determined, wherein the column value is prioritized over the partition value, and wherein the partition value is prioritized over the table value. The data of the table stored in the column is loaded from the disk storage into the memory based on the hierarchy. A query is processed based on the data loaded into the memory.

Hierarchical metadata enhancements for a memory management system

A database system providing self-tuned parallel database recovery is described. In one embodiment, for example, in a database system, a method is described for performing recovery operations using an optimal number of recovery threads, the method comprises steps of: (a) spawning an initial recovery thread to perform recovery operations; (b) measuring I/O (input/output) performance with the initial recovery thread; (c) spawning a subsequent recovery thread to perform recovery operations; (d) measuring I/O performance with the subsequent recovery thread; and (e) as long as I/O performance does not degrade beyond a preselected percentage, repeating steps (c) and (d) for spawning a desired number of additional recovery threads. In another embodiment, the database system auto-tunes the cache during performance of database recovery operations to optimize the performance of recovery operations.

Database system providing self-tuned parallel database recovery

A database system providing methodology for extended memory support is described. In one embodiment, for example, a method is described for extended memory support in a database system having a primary cache, the method comprises steps of: creating a secondary cache in memory available to the database system; mapping a virtual address range to at least a portion of the secondary cache; when the primary cache is full, replacing pages from the primary cache using the secondary cache; in response to a request for a particular page, searching for the particular page in the secondary cache if the particular page is not found in the primary cache; if the particular page is found in the secondary cache, determining a virtual address in the secondary cache where the particular page resides based on the mapping; and swapping the particular page found in the secondary cache with a page in the primary cache, so as to replace a page in the primary cache with the particular page from the secondary cache.

Database system providing methodology for extended memory support

A database system providing improved methods for asynchronous logging of transactions is described. Log records are created describing changes to a database made by a transaction. When a command committing changes to the database for the transaction is received, a logging request is placed in a queue. An asynchronous logging service removes requests from the queue and transfers log records from the transaction to a shared cache. The shared cache stores log records before they are written to the transaction log. The logging service writes log pages containing log records for the transaction from the cache to the transaction log. After all log pages in the cache for the transaction have been written to the transaction log, changes to the database made by the transaction can be committed to the database.

Database system with improved methods for asynchronous logging of transactions

A multi-tier database system is modified such that a middle-tier application server (EJB server) and a database server run on the same host computer and communicate via shared-memory interprocess communication. The system includes a database (e.g., JDBC) driver thread that attaches to the database server, specifically by attaching to the database server's shared memory segment. Operation of the JDBC driver is modified to provide direct access between the middle tier (i.e., EJB server) and the database server, when the two are operating on the same host computer.

Growing community of inventors

San Ramon, CA, United States of America

Prasanta Ghosh