Configure the MD5 hash string of a raster object using ST_SetMD5Sum - PolarDB

Stores a provided MD5 hash string in the metadata of a raster object.

Syntax

text ST_SetMD5Sum(raster raster_obj, text md5sum)

Parameters

Parameter	Description
`raster_obj`	The raster object.
`md5sum`	The MD5 hash string to store. Must be exactly 32 characters and contain only digits and lowercase letters.

Description

ST_SetMD5Sum writes the provided MD5 hash string to the metadata of the raster object.

To automatically calculate and store the MD5 hash string when a raster object is saved, configure the following parameter:

Parameter	Type	Default	Description
`ganos.raster.calculate_md5`	Boolean	`false`	Specifies whether to calculate and store the MD5 hash string in metadata when the raster object is stored. Valid values: `true` \| `false`.

SET ganos.raster.calculate_md5 = true;

Examples

Set and immediately verify the MD5 hash string:

SELECT ST_MD5SUM(ST_SetMD5Sum(rast, '21f41fd983d3139c75b04bff2b7bf5c9'))
FROM raster_table
WHERE id = 1;

              st_md5sum
-----------------------------------
 21f41fd983d3139c75b04bff2b7bf5c9

Related functions

ST_MD5Sum — retrieves the MD5 hash string stored in a raster object's metadata.