Class RelationShapeOnly

java.lang.Object
dev.frostlake.executor.RelationShapeOnly

public final class RelationShapeOnly extends Object
A thread-local mode in which a relation is read for its SHAPE and never for its rows: every base source resolves to zero rows and a FROM-less item that cannot be computed is left NULL, so the columns come out typed by the static channel while nothing value-dependent runs.

CREATE VIEW derives its column list this way (live-verified): a body whose values would fault at row time — a cast to a narrower VARCHAR, 1/0, TO_DATE of text that is no date, a number past its declared width — is a view all the same, DESCRIBE knows its columns, and the fault waits for whoever selects from it. A body that does not COMPILE — an unknown column or function, an argument family a function refuses — is still refused at CREATE, because the static checks run over zero rows exactly as they run over any.

  • Method Details

    • isActive

      public static boolean isActive()
      Whether the current thread is reading shapes only.
    • begin

      public static boolean begin()
      Enter the mode; hands back the state to put back with end(boolean).
    • end

      public static void end(boolean previous)