### COLLECT_SET Function
```sql
collect_set([distinct] expr)
```
#### Function Description
The `collect_set` function is used to collect and return a set of unique elements from a given set of input data. This function can handle input data of any type and returns the result as an array. When the `distinct` keyword is specified, the function will compute the deduplicated set. However, note that the function inherently performs deduplication, so the `distinct` keyword does not affect the result in this context.

#### Parameter Description
* `expr`: Can be an expression of any type.

#### Return Result
* Returns an array where the element types are the same as the input parameter types.
* The function does not sort the result, so the order of elements in the returned array is not determined.
* If the input data contains `null` values, `null` will not be included in the final array result.

#### Usage Example
1. Collect a set of integers:
```sql
SELECT collect_set(col) FROM VALUES (1), (2), (1), (null) AS tab(col);
-- Return result: [1, 2]
```
2. Collect a set of strings:
```sql
SELECT collect_set(col) FROM VALUES ("a"), ("b"), (null), ("c") AS tab(col);
-- Return result: ["a", "b", "c"]
```
### 3. Collecting Mixed Type Collections with Duplicate Values: 
```sql
SELECT collect_set(expr) FROM VALUES (true), (false), (true), (null), ('text') AS tab(expr);
-- Return result: [true, false, 'text']
```
4. Collect Date and Time Sets:
```sql
SELECT collect_set(timestamp) FROM VALUES (TIMESTAMP "2023-03-01 10:00:00"), (TIMESTAMP "2023-03-01 11:00:00"), (null), (TIMESTAMP "2023-03-01 10:00:00") AS tab(timestamp);
-- Return result: [TIMESTAMP "2023-03-01 10:00:00", TIMESTAMP "2023-03-01 11:00:00"]
```
5. Collect collections with different data types:
```sql
SELECT collect_set(expr) FROM VALUES (1), (true), ('string'), (null), (3.14) AS tab(expr);
-- Return result: [1, true, 'string', 3.14]
```
#### Notes
* When the input data is entirely `null`, the `collect_set` function will return an empty array.
* Since the order of elements in the array returned by the `collect_set` function is not guaranteed, subsequent logical judgments or processing should not rely on the order of the results.
* When dealing with large datasets, please be aware that this function may consume a significant amount of memory and computational resources.