parquetWrite

Arguments

filename

Scalar string specifying the output file. Supported extensions are .parquet and .arrow.

data

A table or timeseries containing the data to write.

compression

Scalar string or string array specifying the compression algorithm for Parquet files. If a scalar string is provided, the compression applies to the entire file. If a string array (with length matching the number of variables) is provided, each element specifies the compression for the corresponding variable. Supported values are "gzip" (default), "snappy", "zstd" and "uncompressed".

Description

parquetWrite writes the contents of a table or timeseries to a Parquet (.parquet) or Arrow (.arrow) file.

Each column of the file corresponds to a column of the table.

The name of the column are the same as in the table.

Examples

a = ["A"; "B"; "C"];
b = hours([1;3;5]);
c = rand(3,1);
t = table(a, b, c, "VariableNames", ["string", "hours", "double"]);
parquetWrite(fullfile(TMPDIR, "data.parquet"), t)
parquetRead(fullfile(TMPDIR, "data.parquet"))

// t = [3x3 table]
// 
//    string    hours      double  
//    ______   ________   _________
//                                 
//    A        01:00:00   0.2113249
//    B        03:00:00   0.7560439
//    C        05:00:00   0.0002211

a = ["A"; "B"; "C"];
b = hours([1;3;5]);
c = rand(3,1);
ts = timeseries(b, a, c, "VariableNames", ["hours", "string", "double"]);
parquetWrite(fullfile(TMPDIR, "data.parquet"), ts)
ts2 = parquetRead(fullfile(TMPDIR, "data.parquet"), "OutputType", "timeseries")

// ts2 = [3x2 timeseries]
//
//    hours     string    double  
//   ________   ______   _________
//                                
//   01:00:00   A        0.2113249
//   03:00:00   B        0.7560439
//   05:00:00   C        0.0002211

See also

• parquetRead — Read a Parquet or Arrow file and return a table/timeseries.
• table — create a table from variables
• timeseries — create a timeseries - table with time as index
• datetime — create points in time
• duration — create a duration - duration in hours, minutes and seconds

History