Document NTILE

src/docs/asciidoc/en/refdocs/fblangref40/_fblangref40-functions-window.adoc

@@ -394,11 +394,11 @@ select
 ----
 id  salary  dense_rank  rank  row_number  sum
 --  ------  ----------  ----  ----------  ---
-3     8.00           1     1           1    1
-4     9.00           2     2           2    2
-1    10.00           3     3           3    4
-5    10.00           3     3           4    4
-2    12.00           4     5           5    5
+ 3    8.00           1     1           1    1
+ 4    9.00           2     2           2    2
+ 1   10.00           3     3           3    4
+ 5   10.00           3     3           4    4
+ 2   12.00           4     5           5    5
 ----
 
 The difference between `DENSE_RANK` and `RANK` is that there is a gap related to duplicate rows (relative to the window ordering) only in `RANK`.
@@ -442,12 +442,12 @@ order by salary;
 [listing]
 ----
 id salary cume_dist
-- ------- ---------
-3    8.00       0.2
-4    9.00       0.4
-1   10.00       0.8
-5   10.00       0.8
-2   12.00         1
+-- ------ ---------
+ 3   8.00       0.2
+ 4   9.00       0.4
+ 1  10.00       0.8
+ 5  10.00       0.8
+ 2  12.00         1
 ----
 
 .See also <<fblangref40-windowfuncs-rank>>, <<fblangref40-windowfuncs-perc-rank>>
@@ -488,16 +488,71 @@ order by salary;
 [listing]
 ----
 id salary dense_rank
-- ------ -----------
-3   8.00           1
-4   9.00           2
-1  10.00           3
-5  10.00           3
-2  12.00           4
+-- ------ ----------
+ 3  8.00           1
+ 4  9.00           2
+ 1 10.00           3
+ 5 10.00           3
+ 2 12.00           4
 ----
 
 .See also <<fblangref40-windowfuncs-rank>>, <<fblangref40-windowfuncs-row-number>>
 
+[[fblangref40-windowfuncs-ntile]]
+=== `NTILE()`
+
+.Available in
+DSQL, PSQL
+
+.Result type
+`BIGINT`
+
+.Syntax
+[listing,subs=+quotes]
+----
+NTILE ( _number_of_tiles_ ) OVER <window_name_or_spec>
+----
+
+[[fblangref40-windowfuncs-tbl-ntile]]
+.Arguments of `NTILE`
+[cols="<1,<3", options="header",stripes="none"]
+|===
+^| Argument
+^| Description
+
+|number_of_tiles
+|Number of tiles (groups).
+Restricted to a positive integer literal, a named parameter (PSQL), or a positional parameter (DSQL).
+|===
+
+`NTILE` distributes the rows of the current window partition into the specified number of tiles (groups).
+
+[[fblangref40-windowfuncs-ntile-exmpl]]
+==== `NTILE` Examples
+
+[source]
+----
+select
+  id,
+  salary,
+  rank() over (order by salary),
+  ntile(3) over (order by salary)
+from employee
+order by salary;
+----
+
+.Result
+[listing]
+----
+ID SALARY RANK NTILE
+== ====== ==== =====
+ 3   8.00    1     1
+ 4   9.00    2     1
+ 1  10.00    3     2
+ 5  10.00    3     2
+ 2  12.00    5     3
+----
+
 [[fblangref40-windowfuncs-perc-rank]]
 === `PERCENT_RANK()`
 
@@ -536,12 +591,12 @@ order by salary;
 [listing]
 ----
 id salary rank percent_rank
-- ------- ---- ------------
-3    8.00    1            0
-4    9.00    2         0.25
-1   10.00    3          0.5
-5   10.00    3          0.5
-2   12.00    5            1
+-- ------ ---- ------------
+ 3   8.00    1            0
+ 4   9.00    2         0.25
+ 1  10.00    3          0.5
+ 5  10.00    3          0.5
+ 2  12.00    5            1
 ----
 
 .See also <<fblangref40-windowfuncs-rank>>, <<fblangref40-windowfuncs-cume-dist>>
@@ -582,12 +637,12 @@ order by salary;
 [listing]
 ----
 id salary rank
-- ------ -----
-3   8.00     1
-4   9.00     2
-1  10.00     3
-5  10.00     3
-2  12.00     5
+-- ------ ----
+ 3  8.00     1
+ 4  9.00     2
+ 1 10.00     3
+ 5 10.00     3
+ 2 12.00     5
 ----
 
 .See also
@@ -627,12 +682,12 @@ order by salary;
 [listing]
 ----
 id salary rank
-- ------ -----
-3   8.00     1
-4   9.00     2
-1  10.00     3
-5  10.00     4
-2  12.00     5
+-- ------ ----
+ 3  8.00     1
+ 4  9.00     2
+ 1 10.00     3
+ 5 10.00     4
+ 2 12.00     5
 ----
 
 .See also