# Data Compression in C#

> Please refer to the Data Compression page for a discussion of the advantages of in-memory and persistent database compression.

> ## In-Memory Database Compression

> For C# in-memory database applications the Database.Parameters for managing data compression are `CompressionLevel`, `CompressionMask` and `ExpectedCompressionRatio` which have the same effect as the corresponding `mode_mask` parameters for C applications. Please see the C API Data Compression page for details. The mode bit `MCO_DB_INMEMORY_COMPRESSION` is automatically applied to the mode mask if some non default (not -1) `CompressionLevel` is set. So it is not necessary to set this flag to field `Mode` manually.

> ## Persistent Database Compression

> It is not currently possible to enable persistent database compression on Windows systems. Note that eXtremeDB implements LZ compression in two special file system libraries: `mcofu98zip` and `mcofu98ziplog` which are only available on Unix systems like Linux, MacOS and Solaris.