Column compression

Enterprise Edition

Column compression is available exclusively in the Enterprise Edition. Now supported only by the MemCS engine.

Column compression, introduced in Tarantool Enterprise Edition 3.7.0, aims to save memory space. It compresses a range of consecutive values and stores them in a compressed block. Default block size is 50-100 values.

The following compression algorithms are supported:

A column of any type can be compressed, however the “external” values (the strings that are longer than 12 characters) are not yet compressed.

Note

Only non-indexed columns can be compressed. The compression can be enabled only during the space creation.

Compression settings:

acceleration – LZ4-specific configuration parameter:
- allowed range: 1…65537
- recommended: 10…1000
- higher values improve compression and decompression speed, but reduce the compression ratio

Example:

local format = {
    {'c1', 'uint64'},
    {'c2', 'string', is_nullable = true, compression = 'lz4'},
    {'c3', 'int32', compression = {type = 'lz4', acceleration = 1000}},
}
box.schema.create_space('test', {
    engine = 'memcs', field_count = #format, format = format,
})

Version:

Column compression