# `gdal vector partition`

Added in version 3.12.

Partition a vector dataset into multiple files.

## Synopsis

    Usage: gdal vector partition [OPTIONS] <INPUT> <OUTPUT>

    Partition a vector dataset into multiple files.

    Positional arguments:
      -i, --input <INPUT>                                  Input vector datasets [required]
      -o, --output <OUTPUT>                                Output directory [required]

    Common Options:
      -h, --help                                           Display help message and exit
      --json-usage                                         Display usage as JSON document and exit
      --config <KEY>=<VALUE>                               Configuration option [may be repeated]
      -q, --quiet                                          Quiet mode (no progress bar)

    Options:
      --overwrite                                          Whether overwriting existing output is allowed
                                                           Mutually exclusive with --append
      --append                                             Whether appending to existing layer is allowed
                                                           Mutually exclusive with --overwrite
      -f, --of, --format, --output-format <OUTPUT-FORMAT>  Output format
      --co, --creation-option <KEY>=<VALUE>                Creation option [may be repeated]
      --lco, --layer-creation-option <KEY>=<VALUE>         Layer creation option [may be repeated]
      --field <FIELD>                                      Field(s) on which to partition [may be repeated] [required]
      --scheme <SCHEME>                                    Partitioning scheme. SCHEME=hive|flat (default: hive)
      --pattern <PATTERN>                                  Filename pattern ('part_%010d' for scheme=hive, '{LAYER_NAME}_{FIELD_VALUE}_%010d' for scheme=flat)
      --feature-limit <FEATURE-LIMIT>                      Maximum number of features per file
      --max-file-size <MAX-FILE-SIZE>                      Maximum file size (MB or GB suffix can be used)
      --omit-partitioned-field                             Whether to omit partitioned fields from target layer definition
      --skip-errors                                        Skip errors when writing features

    Advanced Options:
      --if, --input-format <INPUT-FORMAT>                  Input formats [may be repeated]
      --oo, --open-option <KEY>=<VALUE>                    Open options [may be repeated]

## Description

gdal vector partition dispatches features into different files, depending on the values the feature take on a subset of fields specified by the user.

Two partitioning schemes are available:

- `hive`, corresponding to Apache Hive partitioning, is the default one.

  Each partitioning field corresponds to a nested directory. Let's consider a layer with fields "continent" and "country", chosen as partitioning fields. All features where "continent" evaluates to "Europe" and "country" evaluates to "France", will be written in the "continent=Europe/country=France/" subdirectory of the output directory.

  NULL values for partitioning fields are encoded as `__HIVE_DEFAULT_PARTITION__` in the directory name. Non-ASCII characters, space, equal sign, or characters not compatible with directory name constraints are percent-encoded (e.g. `%20` for space).

- `flat` where files are written directly under the output directory using a default filename pattern of `{LAYER_NAME}_{FIELD_VALUE}_%10d`.

By default, the format of the input dataset will be used for the output, if it can be determined and the input driver supports writing. Otherwise, `--format` must be used.

gdal vector partition can be used as the last step of a pipeline.

The following options are available:

### Standard options

--output <OUTPUT-DIRECTORY>

  Root of the output directory. [required]

--field <FIELD-NAME>

  Fields(s) on which to partition. [required]

  Only fields of type String, Integer and Integer64 are allowed. The order into which fields are specified matter to determine the directory hierarchy.

-f, --of, --format, --output-format <OUTPUT-FORMAT>

  Which output vector format to use. Allowed values may be given by `gdal --formats | grep vector | grep rw | sort`

--co <NAME>=<VALUE>

  Many formats have one or more optional dataset creation options that can be used to control particulars about the file created. For instance, the GeoPackage driver supports creation options to control the version.

  May be repeated.

  The dataset creation options available vary by format driver, and some simple formats have no creation options at all. A list of options supported for a format can be listed with the --formats command line option but the documentation for the format is the definitive source of information on driver creation options. See Vector drivers format specific documentation for legal creation options for each format.

  Note that dataset creation options are different from layer creation options.

--layer-creation-option <NAME>=<VALUE>

  Many formats have one or more optional layer creation options that can be used to control particulars about the layer created. For instance, the GeoPackage driver supports layer creation options to control the feature identifier or geometry column name, setting the identifier or description, etc.

  May be repeated.

  The layer creation options available vary by format driver, and some simple formats have no layer creation options at all. A list of options supported for a format can be listed with the --formats command line option but the documentation for the format is the definitive source of information on driver creation options. See Vector drivers format specific documentation for legal creation options for each format.

  Note that layer creation options are different from dataset creation options.

--overwrite

  Allow program to overwrite existing target file or dataset. Otherwise, by default, gdal errors out if the target file or dataset already exists.

--append

  Whether the output directory must be opened in append mode. Implies that it already exists and that the output format supports appending.

  This mode is useful when adding new features to an already an existing partitioned dataset.

--scheme hive|flat

  Partitioning scheme. Defaults to `hive`.

--pattern <PATTERN>

  Filename pattern. User chosen string, with substitutions for:

  - `{LAYER_NAME}`, when found, is substituted with the layer name (percent encoded where needed).

  - `{FIELD_VALUE}`, when found, is substituted with the partitioning field value (percent encoded where needed). If several partitioning fields are used, each value is separated by underscore (_). Empty strings are substituted with `__EMPTY__` and null fields with `__NULL__`.

  - `%[0?][0-9]?[0]?d`: C-style integer formatter for the part number. Valid values are for example `%d` or `%05d`. One and only one part number specifier must be present in the pattern.

  Default values for the pattern are `part_%010d` for the hive scheme, and `{LAYER_NAME}_{FIELD_VALUE}_%010d` for the flat scheme.`

--feature-limit <FEATURE-LIMIT>

  Maximum number of features per file. By default, unlimited. If the limit is exceeded, several parts are created.

--max-file-size <MAX-FILE-SIZE>

  Maximum file size (MB or GB suffix can be used). By default, unlimited. If the limit is exceeded, several parts are created.

  Note that the maximum file size is used as a hint, and might not be strictly respected, because the evaluation of the file size corresponding to a feature is based on a heuristics, as the file size itself cannot be reliably used when it is under writing. In particular, the heuristics does not assume any compression, so for compressed formats, the actual size of a part can be significantly smaller than the specified limit.

--omit-partitioned-field

  Whether to omit partitioned fields from the target layer definition. Automatically set for Parquet output format and Hive partitioning.

--skip-errors

  Whether failures to write feature(s) should be ignored. Note that this option sets the size of the transaction unit to one feature at a time, which may cause severe slowdown when inserting into databases.

### Advanced options

--oo <NAME>=<VALUE>

  Dataset open option (format specific).

  May be repeated.

--if <format>

  Format/driver name to be attempted to open the input file(s). It is generally not necessary to specify it, but it can be used to skip automatic driver detection, when it fails to select the appropriate driver. This option can be repeated several times to specify several candidate drivers. Note that it does not force those drivers to open the dataset. In particular, some drivers have requirements on file extensions.

  May be repeated.

## Examples

### Example 1: Create a partition based on the "continent" and "country" fields

    $ gdal vector partition world_cities.gpkg out_directory --field continent,country --format Parquet

### Example 2: Create a partition based on the "country" field, filtering on cities with population bigger than 1 million, with a flat partitioning scheme

    $ gdal pipeline ! read world_cities.gpkg ! filter --where "pop > 1e6" ! partition out_directory --field country --format GPKG --scheme flat