alter_srs

Use the alter_srs command to update a spatial reference system definition in the database.

When this command is processed, information about the spatial reference system is updated in the DB2GSE.ST_SPATIAL_REFERENCE_SYSTEMS catalog view.

Restriction: You cannot alter a spatial reference system if a registered spatial column uses that spatial reference system.

Attention: Use care with this stored procedure. If you use this stored procedure to change offset, scale, or coordinate system name parameters of the spatial reference system, and if you have existing spatial data that is associated with the spatial reference system, you might inadvertently change the spatial data. If spatial data is affected, you are responsible for ensuring that the changed spatial data is still accurate and valid.

Authorization

The user ID under which the command is invoked must have either SYSADM or DBADM authority.

Command syntax

DSN5SCLP /alter_srs SUBSYSLOC
	-srsName srs_name
	[-srsId srs_id]
	[-xOffset x_offset]
	[-xScale x_scale]
	[-yOffset y_offset]
	[-yScale y_scale]
	[-zOffset z_offset]
	[-zScale z_scale]
	[-mOffset m_offset]
	[-mScale m_scale]
	[-coordsysName cs_name]
	[-description description_string]

Parameter descriptions

All parameters are required and case-sensitive unless otherwise indicated.

-srsName

Identifies the name of the spatial reference system. You must specify a non-empty value for this parameter.

-srsId

Uniquely identifies the spatial reference system. This parameter is optional.

This numeric identifier is used as an input parameter for various spatial functions. If you do not specify this parameter, the numeric identifier of the spatial reference system is not changed.

-xOffset

Specifies the offset for all X coordinates of geometries that are represented in this spatial reference system. This parameter is optional.

If you do not specify this parameter, the value for this parameter in the definition of the spatial reference system is not changed.

The offset is subtracted before the scale factor -xScale is applied when geometries are converted from external representations (WKT, WKB, shape) to the IBM® Spatial Support for Db2 for z/OS® internal representation. (WKT is well-known text, and WKB is well-known binary.)

-xScale

Specifies the scale factor for all X coordinates of geometries that are represented in this spatial reference system. This parameter is optional.

If this parameter is not specified, the value for this parameter in the definition of the spatial reference system is not changed.

The scale factor is applied (multiplication) after the offset -xOffset is subtracted when geometries are converted from external representations (WKT, WKB, shape) to the IBM Spatial Support for Db2 for z/OS internal representation.

-yOffset

Specifies the offset for all Y coordinates of geometries that are represented in this spatial reference system. This parameter is optional.

If this parameter is not specified, the value for this parameter in the definition of the spatial reference system is not changed.

The offset is subtracted before the scale factor -yScale is applied when geometries are converted from external representations (WKT, WKB, shape) to the IBM Spatial Support for Db2 for z/OS internal representation.

-yScale

Specifies the scale factor for all Y coordinates of geometries that are represented in this spatial reference system. This parameter is optional.

If this parameter is not specified, the value for this parameter in the definition of the spatial reference system is not changed.

The scale factor is applied (multiplication) after the offset -yOffset is subtracted when geometries are converted from external representations (WKT, WKB, shape) to the IBM Spatial Support for Db2 for z/OS internal representation. This scale factor must be the same as -xScale.

-zOffset

Specifies the offset for all Z coordinates of geometries that are represented in this spatial reference system. This parameter is optional.

If this parameter is not specified, the value for this parameter in the definition of the spatial reference system is not changed.

The offset is subtracted before the scale factor -zScale is applied when geometries are converted from external representations (WKT, WKB, shape) to the IBM Spatial Support for Db2 for z/OS internal representation.

-zScale

Specifies the scale factor for all Z coordinates of geometries that are represented in this spatial reference system. This parameter is optional.

If this parameter is not specified, the value for this parameter in the definition of the spatial reference system is not changed.

The scale factor is applied (multiplication) after the offset -zOffset is subtracted when geometries are converted from external representations (WKT, WKB, shape) to the IBM Spatial Support for Db2 for z/OS internal representation.

-mOffset

Specifies the offset for all M coordinates of geometries that are represented in this spatial reference system. This parameter is optional.

If this parameter is not specified, the value for this parameter in the definition of the spatial reference system is not changed.

The offset is subtracted before the scale factor -mScale is applied when geometries are converted from external representations (WKT, WKB, shape) to the IBM Spatial Support for Db2 for z/OS internal representation.

-mScale

Specifies the scale factor for all M coordinates of geometries that are represented in this spatial reference system. This parameter is optional.

If this parameter is not specified, the value for this parameter in the definition of the spatial reference system is not changed.

The scale factor is applied (multiplication) after the offset -mOffset is subtracted when geometries are converted from external representations (WKT, WKB, shape) to the IBM Spatial Support for Db2 for z/OS internal representation.

-coordsysName

Uniquely identifies the coordinate system on which this spatial reference system is based. This parameter is optional.

If this parameter is not specified, the coordinate system that is used for the spatial reference system is not changed.

The coordinate system must be listed in the view DB2GSE.ST_COORDINATE_SYSTEMS.

-description

Describes the spatial reference system by explaining its application. This parameter is optional.

If this parameter is not specified, the description information about the spatial reference system is not changed.

Example

This example shows the alter_srs command with all of the parameters specified.

DSN5SCLP alter_srs SUBSYSLOC +
-srsName NEW_SRS_2006 -srsId 2002 -xOffset -180 +
-xScale 5000000 -yOffset -90 -yScale 5000000 +
-zOffset 0 -zScale 1 -mOffset 0 -mScale 1 +
-coordsysName COORD_SYS1 -description NEW_SRS_2006v2