fix array index func with decimal
in old analyzer when sql with array_position or array_contains with decimal , may loss precision to which will make result wrong
FEATURE:
1. enable array type in Nereids
2. support generice on function signature
3. support array and map type in type coercion and type check
4. add element_at and element_slice syntax in Nereids parser
REFACTOR:
1. remove AbstractDataType
BUG FIX:
1. remove FROM from nonReserved keyword list
TODO:
1. support lambda expression
2. use Nereids' way do function type coercion
3. use castIfnotSame when do implict cast on BoundFunction
4. let AnyDataType type coercion do same thing as function type coercion
5. add below array function
- array_apply
- array_concat
- array_filter
- array_sortby
- array_exists
- array_first_index
- array_last_index
- array_count
- array_shuffle shuffle
- array_pushfront
- array_pushback
- array_repeat
- array_zip
- reverse
- concat_ws
- split_by_string
- explode
- bitmap_from_array
- bitmap_to_array
- multi_search_all_positions
- multi_match_any
- tokenize
if we write sql with : `select cast(array() as array<varchar(10)>)`
castexpr in fe will call analyze() with `Type.matchExactType(childType, type, true);`
here array type only check contains_null , but should check inner type to make array matchExactType right
if we write sql with : select array(1.0,2.0,null, null,2.0)
here will pass arg type with uint8 to be which does not match array() func sign with deicmal, and make be core. so here should cast from be and make null tag to cast decimal type
This function can be used to replace bitmap_union(to_bitmap(expr))， because bitmap_union(to_bitmap(expr)) need create many many small bitmaps firstly and then merge them into a single bitmap.
bitmap_agg will convert the column value into a bitmap directly. Its performance is better than bitmap_union(to_bitmap(expr)) . In our test , there is about 30% improvement.
count_by_enum(expr1, expr2, ... , exprN);
Treats the data in a column as an enumeration and counts the number of values in each enumeration. Returns the number of enumerated values for each column, and the number of non-null values versus the number of null values.
Problem:
When create view with projection group_concat(xxx, xxx order by orderkey). It will failed during second parse of inline view
For example:
it works when doing
"SELECT id, group_concat(`name`, "," ORDER BY id) AS test_group_column FROM test GROUP BY id"
but when create view it does not work
"create view test_view as SELECT id, group_concat(`name`, "," ORDER BY id) AS test_group_column FROM test GROUP BY id"
Reason:
when creating view, we will doing parse again of view.toSql() to check whether it has some syntax error. And when doing toSql() to group_concat with order by, it add seperate ', ' between second parameter and order by. So when parsing again, it
would failed because it is different semantic with original statement.
group_concat(`name`, "," ORDER BY id) ==> group_concat(`name`, "," , ORDER BY id)
Solved:
Change toSql of group_concat and add order by statement analyze() of group_concat in Planner cause it would work if we get order by from view statement and do not analyze and binding slot reference to it
New aggregation function: map_agg.
This function requires two arguments: a key and a value, which are used to build a map.
select map_agg(column1, column2) from t group by column3;
we convert input parameters to double for function ceil, floor and round,
because DecimalV2 could not do these operation. Since we intro DecimalV3,
we should convert all parameters to DecimalV3 to get correct result.
For example, when we use double as parameters, we get wrong result:
```sql
select round(341/20000,4),341/20000,round(0.01705,4);
+-------------------------+---------------+-------------------+
| round((341 / 20000), 4) | (341 / 20000) | round(0.01705, 4) |
+-------------------------+---------------+-------------------+
| 0.017 | 0.01705 | 0.0171 |
+-------------------------+---------------+-------------------+
```
DecimalV3 could get correct result
```sql
select round(341/20000,4),341/20000,round(0.01705,4);
+-------------------------+---------------+-------------------+
| round((341 / 20000), 4) | (341 / 20000) | round(0.01705, 4) |
+-------------------------+---------------+-------------------+
| 0.0171 | 0.01705 | 0.0171 |
+-------------------------+---------------+-------------------+
```
When enable two level hash table , if there is zero value in the existing one level hash table, it will cause dead loop when converting to two level hash table, because the PartitionedHashTable::_is_partitioned flag is not set correctly when doing the converting.
Problem:
Select list should be non const when from list have tables or multiple tuples. Or upper query will regard wrong of isConstant
And make wrong constant folding
For example： when using nullif funtion with subquery which result in two alternative constant, planner would treat it as constant expr. So analyzer would report an error of order by clause can not be constant
Solusion:
Change inline view output to non constant, because (select 1 a from table) as view , a in output is no constant when we see
view.a outside
