Compression[05][06][07][08]

The available encoders (compressors) are ZSTD, ZLIB, SNAPPY and in PLAIN. On a record-level base configuration it is done by updating Cell-Value with the desired encoder. On a page-level base that is applied at Cell-Store-Block it is done by defining the default configuration for a schema or by column-schema definition with the encoder to use. Transactions of Communications are configurable at a program specific (application level) with an application designated configuration property and file. Variable-Length integers are used for most of numerical primitives either long-term/persistent storage or intermediate run-time consumption.

Concurrency Control[05][09]

The option to define the maximum cell-versions to keep/retain in SWC-DB is done by configuring the column's Schema property "cell_versions", whereas the order and the revision of a cell is determined by the Cell's definitions of timestamp and it's order DESC/ASC. The timestamp defaults to AUTO that is swcdbRanger application system's time and order to ASC. Additionally to the user-supplied timestamp SWC-DB cell has an internal cell-revision definition that let to determine the latest data that should be retain or removed.

The precision of timestamp used in SWC-DB is in nanoseconds. Whereas the configurable 'cell_ttl' property of a column schema is in milliseconds. The Cell's TTL of the schema is applied against timestamp of a cell and at reach of TTL the cell is auto-considered as non-existing, depends on momentum and max-versions, by changing the Schema's cell-ttl before Compaction has under-go It is a possibility the Cell still exists.

Data Model

Joins

Query Interface