Package dev.frostlake.functions.aggregate

Class Median

java.lang.Object
dev.frostlake.functions.BuiltInFunction
dev.frostlake.functions.AggregateFunction
dev.frostlake.functions.aggregate.Median
public class Median extends AggregateFunction

  • Constructor Details

    • Median

      public Median()

  • Method Details

    • createAccumulator

      public AggregateFunction.Accumulator createAccumulator()
      Description copied from class: AggregateFunction
      Creates the fresh, empty per-group state for one evaluation of this aggregate; the executor makes one per group (or per window partition) and never shares them.
      Specified by:
      createAccumulator in class AggregateFunction
      Returns:
      a new accumulator starting from this aggregate's empty-group state

    • evaluate

      public Object evaluate(List<Object> args)
      Description copied from class: BuiltInFunction
      Computes the function's result over its already-evaluated argument values. A SQL NULL argument arrives as Java null, and returning null makes the SQL result NULL.
      Specified by:
      evaluate in class BuiltInFunction
      Parameters:
      args - the argument values, in call order
      Returns:
      the function's value for these arguments, or null for SQL NULL

    • getMinArgCount

      public int getMinArgCount()
      Description copied from class: BuiltInFunction
      The fewest arguments a call to this function may pass; fewer is an argument-count error.
      Specified by:
      getMinArgCount in class BuiltInFunction
      Returns:
      the minimum accepted argument count

    • getMaxArgCount

      public int getMaxArgCount()
      Description copied from class: BuiltInFunction
      The most arguments a call to this function may pass; Integer.MAX_VALUE marks a variadic function (see BuiltInFunction.isVariadic()).
      Specified by:
      getMaxArgCount in class BuiltInFunction
      Returns:
      the maximum accepted argument count

    • semiStructuredRejection

      public SemiStructuredRejection semiStructuredRejection(int position)
      MEDIAN orders its input against a numeric accumulator, and refuses a semi-structured value with a message shape of its own: live, MEDIAN(o) is "incompatible types: [OBJECT] and [NUMBER(9,0)]" (SQLSTATE 42846, vendor code 1010 — not the 42P13 argument-type list SUM uses), MEDIAN(a) names ARRAY and a structured column names its whole type. It fires on an EMPTY input and inside a GROUP BY alike, while MEDIAN(v) over a VARIANT is accepted.
      Overrides:
      semiStructuredRejection in class BuiltInFunction
      Parameters:
      position - the zero-based argument position being asked about
      Returns:
      the refusal this position gives a semi-structured value, or NONE when undeclared