CREATE CONVERSION
Defines a new encoding conversion.
Synopsis
CREATE [DEFAULT] CONVERSION <name> FOR <source_encoding> TO
<dest_encoding> FROM <funcname>
Description
CREATE CONVERSION
defines a new conversion between character set encodings. Conversion names may be used in the convert function to specify a particular encoding conversion. Also, conversions that are marked DEFAULT
can be used for automatic encoding conversion between client and server. For this purpose, two conversions, from encoding A to B and from encoding B to A, must be defined.
To create a conversion, you must have EXECUTE
privilege on the function and CREATE
privilege on the destination schema.
Parameters
conv_proc(
integer, -- source encoding ID
integer, -- destination encoding ID
cstring, -- source string (null terminated C string)
internal, -- destination (fill with a null terminated C string)
integer -- source string length
) RETURNS void;
Notes
For this release of HAWQ, user-defined functions used in a user-defined cast must be defined as IMMUTABLE
. Any compiled code (shared library files) for custom functions must be placed in the same location on every host in your HAWQ array (master and all segments). This location must also be in the LD_LIBRARY_PATH
so that the server can locate the files.
Examples
To create a conversion from encoding UTF8
to LATIN1
using myfunc
:
CREATE CONVERSION myconv FOR 'UTF8' TO 'LATIN1' FROM myfunc;
Compatibility
There is no CREATE CONVERSION statement in the SQL standard.