Encoding

    • PLAIN

    PLAIN encoding, the default encoding mode, i.e, no encoding, supports multiple data types. It has high compression and decompression efficiency while suffering from low space storage efficiency.

    Second-order differential encoding is more suitable for encoding monotonically increasing or decreasing sequence data, and is not recommended for sequence data with large fluctuations.

    • RLE

    Run-length encoding is suitable for storing sequence with continuous values, and is not recommended for sequence data with most of the time different values.

    GORILLA encoding is lossless. It is more suitable for numerical sequence with similar values and is not recommended for sequence data with large fluctuations.

    Currently, there are two versions of GORILLA encoding implementation, it is recommended to use instead of (deprecated).

    • DICTIONARY

    DICTIONARY encoding is lossless. It is suitable for TEXT data with low cardinality (i.e. low number of distinct values). It is not recommended to use it for high-cardinality data.

    Correspondence between data type and encoding

    The five encodings described in the previous sections are applicable to different data types. If the correspondence is wrong, the time series cannot be created correctly. The correspondence between the data type and its supported encodings is summarized in the Table below.

    The correspondence between the data type and its supported encodings