FileIO indicates that files must be loaded using standard I/O.

LoadToRAM indicates that file must be loaded into RAM.

MemoryMap indicates that that the file must be memory-mapped.

None mode indicates that a block is not compressed.

NoVerification indicates DB should not verify checksum for SSTable blocks.

OnBlockRead indicates checksum should be verified on every SSTable block read.

OnTableAndBlockRead indicates checksum should be verified on SSTable opening and on every block read.

OnTableRead indicates checksum should be verified while opening SSTtable.

Snappy mode indicates that a block is compressed using Snappy algorithm.

ZSTD mode indicates that a block is compressed using ZSTD algorithm.

ChecksumVerificationMode tells when should DB verify checksum for SSTable blocks.

CompressionType specifies how a block should be compressed.

FileLoadingMode specifies how data in LSM table files and value log files should be loaded.