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writer_properties

archiver::archive_format

Function writer_properties 

Source 
pub fn writer_properties(key_value_metadata: Vec<KeyValue>) -> WriterProperties
Expand description

Parquet writer settings for the two-column sample schema.

Timestamps are strictly regular, so delta encoding reduces them to almost nothing. Values come from a 16-bit converter and repeat heavily, so they keep dictionary encoding. zstd compresses the result. Measured on a real 2 kHz MU1 file this is about 14x smaller than uncompressed PLAIN output.

In detail: zstd at the parquet crate’s default level for all columns, dictionary encoding off and DELTA_BINARY_PACKED on for timestamp_unix_ns, and the writer’s defaults for value.

§Arguments

  • key_value_metadata - File-level key-value metadata to store in the footer, for example the calibration entry.