Foreign Keys

Not Supported

Stored Procedures

Supported

Data Model

Array / Matrix

System Architecture

Shared-Nothing

Compression

Run-Length Encoding Null Suppression

SciDB allows users to define how each attribute of an array will be compressed when the array is created. The default is no compression. The additional options are zlib, bzlib, or null filter (null suppression) compression. Since SciDB stores data by attribute, vertically partitioning logical chunks of an array into single-attribute physical chunks, the specified compression is used on a chunk-by-chunk basis. If certain parts of a chunk are accessed more often than others, causing overhead due to decompression and recompression, SciDB can partition a chunk into tiles and compress on a tile-by-tile basis. Run-length encoding is used to compress recurring sequences of data. In addition, SciDB’s storage manager compression engine can split or group logical chunks in order to optimize memory usage while remaining within the limit of the buffer pool’s fixed-size slots.

Storage Model

Custom

Query Interface

Custom API

Storage Architecture

Disk-oriented