Abstract: A shared storage architecture persistently stores database files in non-volatile random access memories (NVRAMs) of computing nodes of a multi-node DBMS. The computing nodes of the multi-node DBMS not only collectively store database data on NVRAMs of the computing nodes, but also host database server instances that process queries in parallel, host database sessions and database processes, and together manage access to a database stored on the NVRAMs of the computing nodes. To perform a data block read operation from persistent storage, a data block may be transferred directly over a network between NVRAM of a computing node that persistently stores the data block to a database buffer in non-volatile RAM of another computing node that requests the data block. The transfer is accomplished using remote direct memory access (“RDMA).

Abstract: A shared storage architecture persistently stores database files in non-volatile random access memories (NVRAMs) of computing nodes of a multi-node DBMS. The computing nodes of the multi-node DBMS not only collectively store database data on NVRAMs of the computing nodes, but also host database server instances that process queries in parallel, host database sessions and database processes, and together manage access to a database stored on the NVRAMs of the computing nodes. To perform a data block read operation from persistent storage, a data block may be transferred directly over a network between NVRAM of a computing node that persistently stores the data block to a database buffer in non-volatile RAM of another computing node that requests the data block. The transfer is accomplished using remote direct memory access (“RDMA).

Abstract: Aspects of the present invention provide a “SuperTag” cache that manages cache at three granularities: (i) coarse grain, multi-block “super blocks,” (ii) single cache blocks and (iii) fine grain, fractional block “data segments.” Since contiguous blocks have the same tag address, by tracking multi-block super blocks, the SuperTag cache inherently increases per-block tag space, allowing higher compressibility without incurring high area overheads. To improve compression ratio, the SuperTag cache uses variable-packing compression allowing variable-size compressed blocks without requiring costly compactions. The SuperTag cache also stores data segments dynamically. In addition, the SuperTag cache is able to further improve the compression ratio by co-compressing contiguous blocks. As a result, the Super Tag cache improves energy and performance for memory intensive applications over conventional compressed caches.

Abstract: Aspects of the present invention provide a “SuperTag” cache that manages cache at three granularities: (i) coarse grain, multi-block “super blocks,” (ii) single cache blocks and (iii) fine grain, fractional block “data segments.” Since contiguous blocks have the same tag address, by tracking multi-block super blocks, the SuperTag cache inherently increases per-block tag space, allowing higher compressibility without incurring high area overheads. To improve compression ratio, the SuperTag cache uses variable-packing compression allowing variable-size compressed blocks without requiring costly compactions. The SuperTag cache also stores data segments dynamically. In addition, the SuperTag cache is able to further improve the compression ratio by co-compressing contiguous blocks. As a result, the Super Tag cache improves energy and performance for memory intensive applications over conventional compressed caches.