update

Author: adriangb

docs/source/user-guide/sql/aggregate_functions.md

@@ -65,6 +65,7 @@ Note: When no rows pass the filter, `COUNT` returns `0` while `SUM`/`AVG`/`MIN`/
 - [mean](#mean)
 - [median](#median)
 - [min](#min)
+- [percentile_cont](#percentile_cont)
 - [string_agg](#string_agg)
 - [sum](#sum)
 - [var](#var)
@@ -388,6 +389,41 @@ min(expression)
 +----------------------+
 ```
 
+### `percentile_cont`
+
+Returns the exact percentile of input values, interpolating between values if needed.
+
+```sql
+percentile_cont(percentile) WITHIN GROUP (ORDER BY expression)
+```
+
+#### Arguments
+
+- **expression**: The expression to operate on. Can be a constant, column, or function, and any combination of operators.
+- **percentile**: Percentile to compute. Must be a float value between 0 and 1 (inclusive).
+
+#### Example
+
+```sql
+> SELECT percentile_cont(0.75) WITHIN GROUP (ORDER BY column_name) FROM table_name;
++----------------------------------------------------------+
+| percentile_cont(0.75) WITHIN GROUP (ORDER BY column_name) |
++----------------------------------------------------------+
+| 45.5                                                     |
++----------------------------------------------------------+
+```
+
+An alternate syntax is also supported:
+
+```sql
+> SELECT percentile_cont(column_name, 0.75) FROM table_name;
++---------------------------------------+
+| percentile_cont(column_name, 0.75)    |
++---------------------------------------+
+| 45.5                                  |
++---------------------------------------+
+```
+
 ### `string_agg`
 
 Concatenates the values of string expressions and places separator values between them. If ordering is required, strings are concatenated in the specified order. This aggregation function can only mix DISTINCT and ORDER BY if the ordering expression is exactly the same as the first argument expression.