Rasql_Error when scale axis to a slicing point

[Bang Pham Huu]

scaling to an interval that contains any slices should throw an error in rasql.

Examples:

SELECT encode(SCALE(c, [100,243]), "csv" ) FROM rgb AS c

and

SELECT encode(SCALE(c, [100:102,243]), "csv" ) FROM rgb AS c

and

SELECT encode(SCALE(c, [100,100:243]), "csv" ) FROM rgb AS c

In all of these cases rasql should throw an exception: "Invalid scaling minterval".

Scaling in rasdaman is handled in source:qlparser/qtbinaryfunc.cc (QtScale class).

[Dimitar Misev]

Please check if scaling to a point is valid in the WCPS standard, perhaps an interval is mandatory.

[Bang Pham Huu]

Dimitar, I think in this case, Rasql should throw an exception when scale at a point, instead of error like this.

rasql -q "select csv(scale( c, [100,243] )) from rgb AS c " --out string
rasql: rasdaman query tool v1.0, rasdaman v9.2.0-beta1-gf79e291 -- generated on 21.01.2016 14:39:26.
opening database RASBASE at localhost:7001...ok
Executing retrieval query...rasdaman error 0: General error received from the server.
aborting transaction...E0209 09:11:56.585736960   12746 tcp_client_posix.c:171]     failed to connect to 'ipv4:10.70.11.237:7002': socket error: connection refused
E0209 09:11:57.586939956   12746 tcp_client_posix.c:171]     failed to connect to 'ipv4:10.70.11.237:7002': socket error: connection refused
E0209 09:11:59.050714220   12746 tcp_client_posix.c:171]     

[Dimitar Misev]

Well scale to "point" in rasql is actually valid. In this case the "point" is a vector of integers, and the respective dimension size is multiplied by the respective values you have in the point.

So for array with sdom [0:399,0:343] scaled with vector [100, 243] you get back an array of size [0:39999,0:83591].. which is really big and that's why the query fails.

See section 9.4 Scaling in the QL guide.

So this case needs to be prevented in WCPS actually.

[Bang Pham Huu]

I agree, it is "SCALEAXES" from WCS as you can scale the axis multiple times. However, I don't know how WCPS can prevent it ? as how can it calculate the size of the output coverage before running this query to Rasql ? I think this ticket can be closed.

[Dimitar Misev]

If it's a valid WCPS request to specify such a vector then it's fine.