# ogr2ogr

Converts simple features data between file formats.

## Synopsis

    Usage: ogr2ogr [--help] [--long-usage] [--help-general]
                   [-of <output_format>] [-dsco <NAME>=<VALUE>]...
                   [-lco <NAME>=<VALUE>]...
                   [[-append]|[-upsert]|[-overwrite]]
                   [-update] [-sql <statement>|@<filename>] [-dialect <dialect>]
                   [-spat <xmin> <ymin> <xmax> <ymax>]
                   [-where <restricted_where>|@<filename>] [-select <field_list>]
                   [-nln <name>] [-nlt <type>]... [-s_srs <srs_def>]
                   [[-a_srs <srs_def>]|[-t_srs <srs_def>]]
                   <dst_dataset_name> <src_dataset_name> [<layer_name>]...

    Field related options:
                   [-addfields] [-relaxedFieldNameMatch]
                   [-fieldTypeToString All|<type1>[,<type2>]...]
                   [-mapFieldType <srctype>|All=<dsttype>[,<srctype2>=<dsttype2>]...]
                   [-fieldmap <field_1>[,<field_2>]...] [-splitlistfields]
                   [-maxsubfields <n>] [-emptyStrAsNull] [-forceNullable]
                   [-unsetFieldWidth] [-unsetDefault] [-resolveDomains]
                   [-dateTimeTo UTC|UTC(+|-)<HH>|UTC(+|-)<HH>:<MM>] [-noNativeData]

    Advanced geometry and SRS related options:
                   [-dim layer_dim|2|XY|3|XYZ|XYM|XYZM] [-s_coord_epoch <epoch>]
                   [-a_coord_epoch <epoch>] [-t_coord_epoch <epoch>]
                   [-ct <pipeline_def>] [-ct_opt <NAME>=<VALUE>]...
                   [-spat_srs <srs_def>] [-geomfield <name>]
                   [-segmentize <max_dist>] [-simplify <tolerance>] [-makevalid]
                   [-skipinvalid] [-wrapdateline] [-datelineoffset <val_in_degree>]
                   [-clipsrc [<xmin> <ymin> <xmax> <ymax>]|<WKT>|<datasource>|spat_extent]
                   [-clipsrcsql <sql_statement>] [-clipsrclayer <layername>]
                   [-clipsrcwhere <expression>]
                   [-clipdst [<xmin> <ymin> <xmax> <ymax>]|<WKT>|<datasource>]
                   [-clipdstsql <sql_statement>] [-clipdstlayer <layername>]
                   [-clipdstwhere <expression>] [-explodecollections]
                   [-zfield <name>]
                   [-gcp <ungeoref_x> <ungeoref_y> <georef_x> <georef_y> [<elevation>]]...
                   [-tps] [-order 1|2|3] [-xyRes <val>[ m|mm|deg]]
                   [-zRes <val>[ m|mm]] [-mRes <val>] [-unsetCoordPrecision]

    Other options:
                   [--quiet] [-progress] [-if <format>]... [-oo <NAME>=<VALUE>]...
                   [-doo <NAME>=<VALUE>]...
                   [-fid <FID>] [-preserve_fid] [-unsetFid]
                   [[-skipfailures]|[-gt <n>|unlimited]]
                   [-limit <nb_features>] [-ds_transaction] [-mo <NAME>=<VALUE>]...
                   [-nomd]

## Description

ogr2ogr can be used to convert simple features data between file formats. It can also perform various operations during the process, such as spatial or attribute selection, reducing the set of attributes, setting the output coordinate system or even reprojecting the features during translation.

--help

  Show this help message and exit

--help-general

  Gives a brief usage message for the generic GDAL commandline options and exit.

-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.

  Added in version 3.2.

-of <format_name>, -f <format_name>

  Output file format name, e.g. `ESRI Shapefile`, `MapInfo File`, `PostgreSQL`. Starting with GDAL 2.3, if not specified, the format is guessed from the extension (previously was ESRI Shapefile).

-append

  Append to existing layer instead of creating new. This option also enables `-update`.

-upsert

  Added in version 3.6.

  Variant of `-append` where the `OGRLayer::UpsertFeature()` operation is used to insert or update features instead of appending with `OGRLayer::CreateFeature()`.

  This is currently implemented only in a few drivers: GPKG -- GeoPackage vector and MongoDBv3.

  The upsert operation uses the FID of the input feature, when it is set and is a "significant" (that is the FID column name is not the empty string), as the key to update existing features. It is crucial to make sure that the FID in the source and target layers are consistent.

  For the GPKG driver, it is also possible to upsert features whose FID is unset or non-significant (`-unsetFid` can be used to ignore the FID from the source feature), when there is a UNIQUE column that is not the integer primary key.

-overwrite

  Delete the output layer and recreate it empty

-update

  Open existing output datasource in update mode rather than trying to create a new one

-select <field_list>

  Comma-delimited list of fields from input layer to copy to the new layer.

  Starting with GDAL 3.9, field names with spaces, commas or double-quote should be surrounded with a starting and ending double-quote character, and double-quote characters in a field name should be escaped with backslash.

  Depending on the shell used, this might require further quoting. For example, to select `regular_field`, `a_field_with space, and comma` and `a field with " double quote` with a Unix shell:

      -select "regular_field,\"a_field_with space, and comma\",\"a field with \\\" double quote\""

  A field is only selected once, even if mentioned several times in the list and if the input layer has duplicate field names.

  Geometry fields can also be specified in the list.

  All fields are selected when -select is not specified. Specifying the empty string can be used to disable selecting any attribute field, and only keep geometries.

  Note this setting cannot be used together with `-append`. To control the selection of fields when appending to a layer, use `-fieldmap` or `-sql`.

-progress

  Display progress on terminal. Only works if input layers have the "fast feature count" capability.

-sql <sql_statement>|@<filename>

  SQL statement to execute. The resulting table/layer will be saved to the output. Starting with GDAL 2.1, the `@filename` syntax can be used to indicate that the content is in the pointed filename. (Cannot be used with `-spat_srs`.)

-dialect <dialect>

  SQL dialect. In some cases can be used to use the (unoptimized) OGR SQL dialect instead of the native SQL of an RDBMS by passing the `OGRSQL` dialect value. The SQL SQLite dialect dialect can be chosen with the `SQLITE` and `INDIRECT_SQLITE` dialect values, and this can be used with any datasource.

-where <restricted_where>|@<filename>

  Attribute query (like SQL WHERE). Starting with GDAL 2.1, the `@filename` syntax can be used to indicate that the content is in the pointed filename.

-skipfailures

  Continue after a failure, skipping the failed feature.

-spat <xmin> <ymin> <xmax> <ymax>

  spatial query extents, in the SRS of the source layer(s) (or the one specified with `-spat_srs`). Only features whose geometry intersects the extents will be selected. The geometries will not be clipped unless `-clipsrc` is specified.

-spat_srs <srs_def>

  Override spatial filter SRS. (Cannot be used with `-sql`.)

-geomfield <field>

  Name of the geometry field on which the spatial filter operates on.

-dsco <NAME>=<VALUE>

  Dataset creation option (format specific)

-lco <NAME>=<VALUE>

  Layer creation option (format specific)

-nln <name>

  Assign an alternate name to the new layer

-nlt <type>

  Define the geometry type for the created layer. One of `NONE`, `GEOMETRY`, `POINT`, `LINESTRING`, `POLYGON`, `GEOMETRYCOLLECTION`, `MULTIPOINT`, `MULTIPOLYGON`, `MULTILINESTRING`, `CIRCULARSTRING`, `COMPOUNDCURVE`, `CURVEPOLYGON`, `MULTICURVE`, and `MULTISURFACE` non-linear geometry types. Add `Z`, `M`, or `ZM` to the type name to specify coordinates with elevation, measure, or elevation and measure. `PROMOTE_TO_MULTI` can be used to automatically promote layers that mix polygon or multipolygons to multipolygons, and layers that mix linestrings or multilinestrings to multilinestrings. Can be useful when converting shapefiles to PostGIS and other target drivers that implement strict checks for geometry types. `CONVERT_TO_LINEAR` can be used to to convert non-linear geometry types into linear geometry types by approximating them, and `CONVERT_TO_CURVE` to promote a non-linear type to its generalized curve type (`POLYGON` to `CURVEPOLYGON`, `MULTIPOLYGON` to `MULTISURFACE`, `LINESTRING` to `COMPOUNDCURVE`, `MULTILINESTRING` to `MULTICURVE`). Starting with version 2.1 the type can be defined as measured ("25D" remains as an alias for single "Z"). Some forced geometry conversions may result in invalid geometries, for example when forcing conversion of multi-part multipolygons with `-nlt POLYGON`, the resulting polygon will break the Simple Features rules.

  Starting with GDAL 3.0.5, `-nlt CONVERT_TO_LINEAR` and `-nlt PROMOTE_TO_MULTI` can be used simultaneously.

-dim <val>

  Force the coordinate dimension to val (valid values are `XY`, `XYZ`, `XYM`, and `XYZM` - for backwards compatibility `2` is an alias for `XY` and `3` is an alias for `XYZ`). This affects both the layer geometry type, and feature geometries. The value can be set to `layer_dim` to instruct feature geometries to be promoted to the coordinate dimension declared by the layer. Support for M was added in GDAL 2.1.

-a_srs <srs_def>

  Assign an output SRS, but without reprojecting (use `-t_srs` to reproject)

  The coordinate reference systems that can be passed are anything supported by the `OGRSpatialReference::SetFromUserInput()` call, which includes EPSG Projected, Geographic or Compound CRS (i.e. EPSG:4296), a well known text (WKT) CRS definition, PROJ.4 declarations, or the name of a .prj file containing a WKT CRS definition.

-a_coord_epoch <epoch>

  Added in version 3.4.

  Assign a coordinate epoch, linked with the output SRS. Useful when the output SRS is a dynamic CRS. Only taken into account if `-a_srs` is used.

-t_srs <srs_def>

  Reproject/transform to this SRS on output, and assign it as output SRS.

  A source SRS must be available for reprojection to occur. The source SRS will be by default the one found in the source layer when it is available, or as overridden by the user with `-s_srs`

  The coordinate reference systems that can be passed are anything supported by the `OGRSpatialReference::SetFromUserInput()` call, which includes EPSG Projected, Geographic or Compound CRS (i.e. EPSG:4296), a well known text (WKT) CRS definition, PROJ.4 declarations, or the name of a .prj file containing a WKT CRS definition.

-t_coord_epoch <epoch>

  Added in version 3.4.

  Assign a coordinate epoch, linked with the output SRS. Useful when the output SRS is a dynamic CRS. Only taken into account if `-t_srs` is used. It is also mutually exclusive with `-a_coord_epoch`.

  Before PROJ 9.4, `-s_coord_epoch` and `-t_coord_epoch` were mutually exclusive, due to lack of support for transformations between two dynamic CRS.

-s_srs <srs_def>

  Override source SRS. If not specified the SRS found in the input layer will be used. This option has only an effect if used together with `-t_srs` to reproject.

  The coordinate reference systems that can be passed are anything supported by the `OGRSpatialReference::SetFromUserInput()` call, which includes EPSG Projected, Geographic or Compound CRS (i.e. EPSG:4296), a well known text (WKT) CRS definition, PROJ.4 declarations, or the name of a .prj file containing a WKT CRS definition.

-xyRes "<val>[ m|mm|deg]"

  Added in version 3.9.

  Set/override the geometry X/Y coordinate resolution. If only a numeric value is specified, it is assumed to be expressed in the units of the target SRS. The m, mm or deg suffixes can be specified to indicate that the value must be interpreted as being in meter, millimeter or degree.

  When specifying this option, the `OGRGeometry::SetPrecision()` method is run on geometries (that are not curves) before passing them to the output driver, to avoid generating invalid geometries due to the potentially reduced precision (unless the `OGR_APPLY_GEOM_SET_PRECISION` configuration option is set to `NO`)

  If neither this option nor `-unsetCoordPrecision` are specified, the coordinate resolution of the source layer, if available, is used.

-zRes "<val>[ m|mm]"

  Added in version 3.9.

  Set/override the geometry Z coordinate resolution. If only a numeric value is specified, it is assumed to be expressed in the units of the target SRS. The m or mm suffixes can be specified to indicate that the value must be interpreted as being in meter or millimeter. If neither this option nor `-unsetCoordPrecision` are specified, the coordinate resolution of the source layer, if available, is used.

-mRes <val>

  Added in version 3.9.

  Set/override the geometry M coordinate resolution. If neither this option nor `-unsetCoordPrecision` are specified, the coordinate resolution of the source layer, if available, is used.

-unsetCoordPrecision

  Added in version 3.9.

  Prevent the geometry coordinate resolution from being set on target layer(s).

-s_coord_epoch <epoch>

  Added in version 3.4.

  Assign a coordinate epoch, linked with the source SRS. Useful when the source SRS is a dynamic CRS. Only taken into account if `-s_srs` is used.

  Before PROJ 9.4, `-s_coord_epoch` and `-t_coord_epoch` were mutually exclusive, due to lack of support for transformations between two dynamic CRS.

-ct <string>

  Added in version 3.0.

  A PROJ string (single step operation or multiple step string starting with +proj=pipeline), a WKT2 string describing a CoordinateOperation, or a urn:ogc:def:coordinateOperation:EPSG::XXXX URN overriding the default transformation from the source to the target CRS.

  It must take into account the axis order of the source and target CRS, that is typically include a `step proj=axisswap order=2,1` at the beginning of the pipeline if the source CRS has northing/easting axis order, and/or at the end of the pipeline if the target CRS has northing/easting axis order.

-ct_opt <NAME>=<VALUE>

  Added in version 3.11.

  Specify a coordinate operation option that influences how PROJ selects coordinate operations when `-ct` is not set.

  The following options are available:

  - `ONLY_BEST``=``YES`/`NO`. By default (at least in the PROJ 9.x series), PROJ may use coordinate operations that are not the "best" if resources (typically grids) needed to use them are missing. It will then fallback to other coordinate operations that have a lesser accuracy, for example using Helmert transformations, or in the absence of such operations, to ones with potential very rough accuracy, using "ballpark" transformations (see https://proj.org/glossary.html). When calling this method with YES, PROJ will only consider the "best" operation, and error out (at Transform() time) if they cannot be used. This method may be used together with `ALLOW_BALLPARK``=``NO` to only allow best operations that have a known accuracy. Note that this method has no effect on PROJ versions before 9.2. The default value for this option can be also set with the `PROJ_ONLY_BEST_DEFAULT` environment variable, or with the `only_best_default` setting of proj.ini. Setting ONLY_BEST=YES/NO overrides such default value.

  - `ALLOW_BALLPARK``=``YES`/`NO`. Whether ballpark coordinate operations are allowed. Default is YES.

  - `WARN_ABOUT_DIFFERENT_COORD_OP``=``YES`/`NO`. Can be set to NO to avoid GDAL warning when different coordinate operations are used to transform the different geometries of the dataset (or part of the same geometry). Default is YES.

-preserve_fid

  Use the FID of the source features instead of letting the output driver automatically assign a new one (for formats that require a FID). If not in append mode, this behavior is the default if the output driver has a FID layer creation option, in which case the name of the source FID column will be used and source feature IDs will be attempted to be preserved. This behavior can be disabled by setting `-unsetFid`. This option is not compatible with `-explodecollections`.

-fid <fid>

  If provided, only the feature with the specified feature id will be processed. Operates exclusive of the spatial or attribute queries. Note: if you want to select several features based on their feature id, you can also use the fact the 'fid' is a special field recognized by OGR SQL. So, -where "fid in (1,3,5)" would select features 1, 3 and 5.

-limit <nb_features>

  Limit the number of features per layer.

-oo <NAME>=<VALUE>

  Dataset open option (format specific).

  If a driver supports the `OGR_SCHEMA` open option, it can be used to partially or completely override the auto-detected schema (i.e. which fields are read, with which types, subtypes, length, precision etc.) of the dataset.

  The value of this option is a JSON string or a path to a JSON file that complies with the OGR_SCHEMA open option schema definition

-doo <NAME>=<VALUE>

  Destination dataset open option (format specific), only valid in -update mode.

-gt <n>

  Group n features per transaction (default 100 000). Increase the value for better performance when writing into DBMS drivers that have transaction support. `n` can be set to unlimited to load the data into a single transaction.

-ds_transaction

  Force the use of a dataset level transaction (for drivers that support such mechanism), especially for drivers such as FileGDB that only support dataset level transaction in emulation mode.

-clipsrc [<xmin> <ymin> <xmax> <ymax>]|WKT|<datasource>|spat_extent

  Clip geometries (before potential reprojection) to one of the following:

  - the specified bounding box (expressed in source SRS)

  - a WKT geometry (POLYGON or MULTIPOLYGON expressed in source SRS)

  - one or more geometries selected from a datasource

  - the spatial extent of the -spat option if you use the spat_extent keyword.

  When specifying a datasource, you will generally want to use -clipsrc in combination of the -clipsrclayer, -clipsrcwhere or -clipsrcsql options.

-clipsrcsql <sql_statement>

  Select desired geometries from the source clip datasource using an SQL query.

-clipsrclayer <layername>

  Select the named layer from the source clip datasource.

-clipsrcwhere <expression>

  Restrict desired geometries from the source clip layer based on an attribute query.

-clipdst [<xmin> <ymin> <xmax> <ymax>]|<WKT>|<datasource>

  Clip geometries (after potential reprojection) to one of the following:

  - the specified bounding box (expressed in destination SRS)

  - a WKT geometry (POLYGON or MULTIPOLYGON expressed in destination SRS)

  - one or more geometries selected from a datasource

  When specifying a datasource, you will generally want to use -clipdst in combination with the -clipdstlayer, -clipdstwhere or -clipdstsql options.

-clipdstsql <sql_statement>

  Select desired geometries from the destination clip datasource using an SQL query.

-clipdstlayer <layername>

  Select the named layer from the destination clip datasource.

-clipdstwhere <expression>

  Restrict desired geometries from the destination clip layer based on an attribute query.

-wrapdateline

  Split geometries crossing the dateline meridian (long. = +/- 180deg)

-datelineoffset

  Offset from dateline in degrees (default long. = +/- 10deg, geometries within 170deg to -170deg will be split)

-simplify <tolerance>

  Distance tolerance for simplification. Note: the algorithm used preserves topology per feature, in particular for polygon geometries, but not for a whole layer.

  The specified value of this option is the tolerance used to merge consecutive points of the output geometry using the `OGRGeometry::SimplifyPreserveTopology()` method The unit of the distance is in georeferenced units of the source vector dataset. This option is applied before the reprojection implied by `-t_srs`

-segmentize <max_dist>

  The specified value of this option is the maximum distance between two consecutive points of the output geometry before intermediate points are added. The unit of the distance is georeferenced units of the source layer. This option is applied before the reprojection implied by `-t_srs`

-makevalid

  Run the `OGRGeometry::MakeValid()` operation, followed by `OGRGeometryFactory::removeLowerDimensionSubGeoms()`, on geometries to ensure they are valid regarding the rules of the Simple Features specification.

-skipinvalid

  Run the `OGRGeometry::IsValid()` operation on geometries to check if they are valid regarding the rules of the Simple Features specification. If they are not, the feature is skipped. This check is done after all other geometry operations.

-fieldTypeToString All|<type1>[,<type2>]...

  Converts any field of the specified type to a field of type string in the destination layer. Valid types are : `Integer`, `Integer64`, `Real`, `String`, `Date`, `Time`, `DateTime`, `Binary`, `IntegerList`, `Integer64List`, `RealList`, `StringList`. Special value `All` can be used to convert all fields to strings. This is an alternate way to using the CAST operator of OGR SQL, that may avoid typing a long SQL query. Note that this does not influence the field types used by the source driver, and is only an afterwards conversion. Also note that this option is without effects on fields whose presence and type is hard-coded in the output driver (e.g KML, GPX). For an alternative way to manipulate field types earlier in the process while they are read from the input dataset see `-oo` `OGR_SCHEMA` (only available for a limited set of formats).

-mapFieldType {<srctype>|All=<dsttype>[,<srctype2>=<dsttype2>]...}

  Converts any field of the specified type to another type. Valid types are : `Integer`, `Integer64`, `Real`, `String`, `Date`, `Time`, `DateTime`, `Binary`, `IntegerList`, `Integer64List`, `RealList`, `StringList`. Types can also include subtype between parenthesis, such as `Integer(Boolean)`, `Real(Float32)`, ... Special value `All` can be used to convert all fields to another type. This is an alternate way to using the CAST operator of OGR SQL, that may avoid typing a long SQL query. This is a generalization of -fieldTypeToString. Note that this does not influence the field types used by the source driver, and is only an afterwards conversion. Also note that this option is without effects on fields whose presence and type is hard-coded in the output driver (e.g KML, GPX). For an alternative way to manipulate field types earlier in the process while they are read from the input dataset see `-oo` `OGR_SCHEMA` (only available for a limited set of formats).

-dateTimeTo {UTC|UTC(+|-)<HH>|UTC(+|-)<HH>:<MM>}

  Converts date time values from the timezone specified in the source value to the target timezone expressed with `-dateTimeTo`. Datetime whose timezone is unknown or localtime are not modified.

  HH must be in the [0,14] range and MM=00, 15, 30 or 45.

-unsetFieldWidth

  Set field width and precision to 0.

-splitlistfields

  Split fields of type StringList, RealList or IntegerList into as many fields of type String, Real or Integer as necessary.

-maxsubfields <val>

  To be combined with `-splitlistfields` to limit the number of subfields created for each split field.

-explodecollections

  Produce one feature for each geometry in any kind of geometry collection in the source file, applied after any `-sql` option. This options is not compatible with `-preserve_fid` but `-sql "SELECT fid AS original_fid, * FROM ..."` can be used to store the original FID if needed.

-zfield <field_name>

  Uses the specified field to fill the Z coordinate of geometries.

-gcp <ungeoref_x> <ungeoref_y> <georef_x> <georef_y> [<elevation>]

  Use the indicated ground control point to compute a coordinate transformation. The transformation method can be selected by specifying the `-order` or `-tps` options. Note that unlike raster tools such as gdal_edit or gdal_translate, GCPs are not added to the output dataset. This option may be provided multiple times to provide a set of GCPs (at least 2 GCPs are needed).

-order <n>

  Order of polynomial used for warping (1 to 3). The default is to select a polynomial order based on the number of GCPs.

-tps

  Force use of thin plate spline transformer based on available GCPs.

-fieldmap

  Specifies the list of field indexes to be copied from the source to the destination. The (n)th value specified in the list is the index of the field in the target layer definition in which the n(th) field of the source layer must be copied. Index count starts at zero. To omit a field, specify a value of -1. There must be exactly as many values in the list as the count of the fields in the source layer. We can use the 'identity' setting to specify that the fields should be transferred by using the same order. This setting should be used along with the `-append` setting.

-addfields

  This is a specialized version of `-append`. Contrary to `-append`, `-addfields` has the effect of adding, to existing target layers, the new fields found in source layers. This option is useful when merging files that have non-strictly identical structures. This might not work for output formats that don't support adding fields to existing non-empty layers. Note that if you plan to use -addfields, you may need to combine it with -forceNullable, including for the initial import.

-relaxedFieldNameMatch

  Do field name matching between source and existing target layer in a more relaxed way if the target driver has an implementation for it.

-forceNullable

  Do not propagate not-nullable constraints to target layer if they exist in source layer.

-unsetDefault

  Do not propagate default field values to target layer if they exist in source layer.

-unsetFid

  Can be specified to prevent the name of the source FID column and source feature IDs from being re-used for the target layer. This option can for example be useful if selecting source features with a ORDER BY clause.

-emptyStrAsNull

  Added in version 3.3.

  Treat empty string values as null.

-resolveDomains

  Added in version 3.3.

  When this is specified, any selected field that is linked to a coded field domain will be accompanied by an additional field (`{dstfield}_resolved`), that will contain the description of the coded value.

-nomd

  To disable copying of metadata from source dataset and layers into target dataset and layers, when supported by output driver.

-mo <META-TAG>=<VALUE>

  Passes a metadata key and value to set on the output dataset, when supported by output driver.

-noNativeData

  To disable copying of native data, i.e. details of source format not captured by OGR abstraction, that are otherwise preserved by some drivers (like GeoJSON) when converting to same format.

  Added in version 2.1.

<dst_dataset_name>

  Output dataset name.

<src_dataset_name>

  Source dataset name.

<layer_name>

  One or more source layer names to copy to the output dataset. If no layer names are passed, then all source layers are copied.

## Performance Hints

When writing into transactional DBMS (SQLite/PostgreSQL,MySQL, etc...), it might be beneficial to increase the number of INSERT statements executed between BEGIN TRANSACTION and COMMIT TRANSACTION statements. This number is specified with the -gt option. For example, for SQLite, explicitly defining -gt 65536 ensures optimal performance while populating some table containing many hundreds of thousands or millions of rows. However, note that -skipfailures overrides -gt and sets the size of transactions to 1.

For PostgreSQL, the `PG_USE_COPY` config option can be set to YES for a significant insertion performance boost. See the PG driver documentation page.

More generally, consult the documentation page of the input and output drivers for performance hints.

## Known issues

Starting with GDAL 3.8, ogr2ogr uses internally an Arrow array based API (cf RFC 86: Column-oriented read API for vector layers) for some source formats (in particular GeoPackage or FlatGeoBuf), and for the most basic types of operations, to improve performance. This substantial change in the ogr2ogr internal logic has required a number of fixes throughout the GDAL 3.8.x bugfix releases to fully stabilize it, and we believe most issues are resolved with GDAL 3.9. If you hit errors not met with earlier GDAL versions, you may specify `--config OGR2OGR_USE_ARROW_API NO` on the ogr2ogr command line to opt for the classic algorithm using an iterative feature based approach. If that flag is needed with GDAL >= 3.9, please file an issue on the GDAL issue tracker.

## C API

This utility is also callable from C with `GDALVectorTranslate()`.

## Examples

### Example 1: Appending to an existing layer

>     ogr2ogr -append -f PostgreSQL PG:dbname=warmerda abc.tab

### Example 2: Clip input layer with a bounding box

> The bounding box is specified as `<xmin> <ymin> <xmax> <ymax>`:

>     ogr2ogr -spat -13.931 34.886 46.23 74.12 output.gpkg natural_earth_vector.gpkg

### Example 3: Filter Features by a `-where` clause

>     ogr2ogr -where "\"POP_EST\" < 1000000" \
>       output.gpkg natural_earth_vector.gpkg ne_10m_admin_0_countries

More examples are given in the individual format pages.

## Advanced examples

### Example 4: Reprojecting from ETRS_1989_LAEA_52N_10E to EPSG:4326 and clipping to a bounding box

>     ogr2ogr -wrapdateline -t_srs EPSG:4326 -clipdst -5 40 15 55 france_4326.shp europe_laea.shp

### Example 5: Outputting geometries with the CSV driver.

By default, this driver does not preserve geometries on layer creation by default. An explicit layer creation option is needed:

>     ogr2ogr -lco GEOMETRY=AS_XYZ TrackWaypoint.csv TrackWaypoint.kml

### Example 6: Extracting only geometries

There are different situations, depending if the input layer has a named geometry column, or not. First check, with ogrinfo if there is a reported geometry column.

>     $ ogrinfo -so CadNSDI.gdb.zip PLSSPoint | grep 'Geometry Column'
>     Geometry Column = SHAPE

In that situation where the input format is a FileGeodatabase, it is called SHAPE and can thus be referenced directly in a SELECT statement.

>     ogr2ogr -sql "SELECT SHAPE FROM PLSSPoint" \
>       -lco GEOMETRY=AS_XY -f CSV /vsistdout/ CadNSDI.gdb.zip

For a shapefile with a unnamed geometry column, `_ogr_geometry_` can be used as a special name to designate the implicit geometry column, when using the default OGR SQL dialect. The name begins with an underscore and SQL syntax requires that it must appear between double quotes. In addition the command line interpreter may require that double quotes are escaped and the final SELECT statement could look like:

>     ogr2ogr -sql "SELECT \"_ogr_geometry_\" FROM PLSSPoint" \
>       -lco GEOMETRY=AS_XY -f CSV /vsistdout/ CadNSDI.shp

If using the SQL SQLite dialect, the special geometry name is `geometry` when the source geometry column has no name.

>     ogr2ogr -sql "SELECT geometry FROM PLSSPoint" -dialect SQLite \
>       -lco GEOMETRY=AS_XY -f CSV /vsistdout/ CadNSDI.shp