slow marray query on small subset

[Dimitar Misev]

Script is attached to reproduce a slow marray query which constructs a 3x20x20 array:

SELECT encode(

  MARRAY T1 in [0:2,0:19,2392:2411]
  VALUES  c.0[T1[0],T1[1],T1[2]] -

          CONDENSE max
          OVER pt in [0:2]
          USING c.0[pt[0],T1[1],T1[2]]

, "csv" ) FROM coll AS c

Equivalent query with max_cells instead of condense shows the same behavior:

SELECT encode(

  MARRAY T1 in [0:2,0:19,2392:2411]
  VALUES  c.0[T1[0],T1[1],T1[2]] -

          max_cells( c.0[0:2,T1[1],T1[2]] )

, "csv" ) FROM coll AS c

[Dimitar Misev]

run ./test.sh ingest the first time to setup the data

[Dimitar Misev]

The problem is that in an expression like c.0[T1[0],T1[1],T1[2]], the .0 is first applied on the whole array c, then subset is applied.

The workaround is to write c[T1[0],T1[1],T1[2]].0, it works fast as expected in this case.