[raster] Add ability to change behavior of WKB output for out-db bands

[dustymugs]

Version 1 is intended to correct the handling of out-db raster bands. In Version 0, the output of ST_AsBinary() for a band with out-db values returns the path to the out of database raster file, which is generally useless for a client unless the client has access to the database server's file system.

By using Version 1, we don't break compatibility for those already using Version 0 WKB.

Related ticket regarding ST_AsBinary() is #2217.

[dustymugs]

Proposed spec for raster WKB v1

[dustymugs]

After some additional thinking and discussion, the current thought is NOT to create a new version and cause lots of waves (and probably a whole slew of bugs) but to continue using the current WKB format as is. Instead, we will allow end users to specify that they want out-db bands to be treated as in-db. By default, the current behavior where out-db bands return the path to the external file will continue. But if the user says to tread out-db as in-db, the behavior will change so that the appropriate data contained in the external file will be returned.

[mloskot]

allow end users to specify that they want out-db bands to be treated as in-db

How that will be realise? What steps at user-end will be required?

[dustymugs]

Replying to mloskot:

allow end users to specify that they want out-db bands to be treated as in-db

How that will be realise? What steps at user-end will be required?

ST_AsBinary(rast raster, OutAsIn boolean DEFAULT FALSE)

For remote clients, OutAsIn should be TRUE so that out-db bands are treated as in-db.

[dustymugs]

Done as of r11320.

[mloskot]

@dustymugs Thanks very much for fixing this.