Hologres is compatible with PostgreSQL and allows you to use standard PostgreSQL syntax for data development.

Hologres supports a subset of PostgreSQL functions. The following table describes the ordered-set aggregate functions that are supported by Hologres.
Function Description Direct argument type Aggregated argument type Example Return type
mode() WITHIN GROUP (ORDER BY sort_expression) Returns the most frequent input value. If multiple values are equally frequent, the function returns the first value. None A sortable type
  • Example

    select mode() WITHIN GROUP (ORDER BY user_id ) from testtable;

  • Result

    293890

 Same as the sorting expression
percentile_cont(fraction) WITHIN GROUP (ORDER BY sort_expression) Continuous percentile: returns a value that corresponds to the specified fraction in the ordering. If needed, the function interpolates a value between adjacent input items. double precision double precision or interval
  • Example

    select percentile_cont(0.5) WITHIN GROUP (ORDER BY cust_id) from testtable;

  • Result

    1105639996.5

 Same as the sorting expression
percentile_cont(fractions) WITHIN GROUP (ORDER BY sort_expression) Multiple continuous percentile: returns an array of results that match the shape of the fractions parameter, with each non-null element replaced by the value that corresponds to that percentile. double precision[] double precision or interval
  • Example

    select percentile_cont(0.5) WITHIN GROUP (ORDER BY member_id) from testtable;

  • Result

    96727903.5

 Array of the same type as the sorting expression
percentile_disc(fraction) WITHIN GROUP (ORDER BY sort_expression) Discrete percentile: returns the first input value whose position in the ordering equals or exceeds the specified percentile. double precision A sortable type
  • Example

    select percentile_disc(0.6) WITHIN GROUP (ORDER BY (impression_id) from testtable;

  • Result

    0.0

 Same as the sorting expression
percentile_disc(fractions) WITHIN GROUP (ORDER BY sort_expression) Multiple discrete percentile: returns an array of results that match the shape of the fractions parameter, with each non-null element replaced by the input value that corresponds to that percentile. double precision[] A sortable type
  • Example

    select percentile_disc(0.6) WITHIN GROUP (ORDER BY (impr_id) from testtable;

  • Result

    0.0

 Array of the same type as the sorting expression