Sap Se

Mehul Wagle

Daniel Booss

Ivan Schreter

Colin Florendo

Robert Schulze

Guenter Radestock

Reza Sherkat

Amit Pathak

Robert Kettler

Pushkar Khadilkar

Harshada Khandekar

Akanksha Meghlan

Disclosed herein are system, method, and computer program product embodiments for providing paged and compressed storage for column data, while maintaining existing access mechanisms for the data. In order to reduce an in-memory footprint for column data, columns may be stored in pageable format using page chains, and only those pages of the column data needed to resolve a query will be placed in memory, and evicted from memory when no longer needed. In order to further reduce the footprint for these columns, compression can be applied, and the compressed column data stored in the same pageable format using page chains. The compressed data includes a plurality of vectors, each of which is converted into pages and stored on the page chain with the others so that they can be efficiently retrieved during database retrieval operations.

Space efficient vector for columnar data storage

A system for allocating memory (e.g., heap) in multi-core processors is provided. In some implementations, the system performs operations comprising receiving, at a shared cache having a plurality of segments, a first data allocation including a plurality of data blocks, and allocating at least a first and second data block from the first allocation. First and second segments in the shared cache can each comprise a plurality of data slots (e.g., of equal length). Allocating the first and second data blocks can include storing the first data block in a data slot of the first segment and storing the second data block in a data slot of the second segment. The plurality of data slots which do not contain data may contain padding, and/or the data slots to which the first and second data blocks are allocated are not adjacent. Related systems, methods, and articles of manufacture are also described.

Memory allocation in multi-core processors

A system includes reception of an instruction to create a data block associated with a portion of a database table in a non-volatile memory system, creation, in response to the instruction to create the data block, of a file associated with the data block in the non-volatile memory system, where a filename of the file comprises an indication that the data block is a temporary block, creation of an entry in a data block map table indicating that the data block is a temporary block, reception of an instruction to commit the data block, and, in response to the instruction to commit the data block, flush data associated with the data block to the file in the non-volatile memory system, rename the file to remove the indication that the data block is a temporary block, and update the entry in the data block map to indicate that the data block is a committed block.

DBMS storage management for non-volatile memory

A system includes a first node including a first processor and a first memory, and a second node including a second processor and a second memory. A worker thread of the first processor calls an allocation API to allocate a portion of the first memory, and calls a first allocator of a first memory manager associated with the first node to allocate a specified size of the first memory. The first memory manager calls an operating system function to reserve a memory segment of the specified size, sets a first Non-Uniform Memory Access policy of the first node to preferred, binds the reserved memory segment to the first node, adds the memory segment to a global freelist, and returns an address pointer of the reserved memory segment to the worker thread.

NUMA-aware memory allocation

Disclosed herein are system, method, and computer program product embodiments for managing non-uniform memory access (NUMA) in a database management system. An embodiment operates by receiving a request to load data from a disk into an in-memory database. An optimal one of the plurality of nodes onto which to load the data from the disk based on a system state is determined. It is determined whether the optimal node has sufficient free local memory in a free list to store the data. If the optimal node does not have sufficient free list memory, a memory allocation is requested from an operating system. An address of the memory storing the data is provided.

Non-uniform memory access (NUMA) database management system

Instances of a call stack executing in a database management system and separated by a sampling interval can be compared and upwardly traversed until reaching a point of difference between the instances. A call counter can be incremented for each new frame identified in the second instance of the call stack since the point of difference such that relative call count frequencies of multiple frames (which can include function calls) can be determined. Systems, methods, and computer program products are described.

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Pune, India

Mehul Wagle