Enhance aggregate function `collect_set` and `collect_list` to support optional `max_size` param,
which enables to limit the number of elements in result array.
1. Fixed a problem with histogram statistics collection parameters.
2. Solved the problem that it takes a long time to collect histogram statistics.
TODO: Optimize histogram statistics sampling method and make the sampling parameters effective.
The problem is that the histogram function works as expected in the single-node test, but doesn't work in the multi-node test. In addition, the performance of the current support sampling to collect histogram is low, resulting in a large time consumption when collecting histogram information.
Fixed the parameter issue and temporarily removed support for sampling to speed up the collection of histogram statistics.
Will next support sampling to collect histogram information.
This pr mainly to optimize the histogram(👉🏻https://github.com/apache/doris/pull/14910) aggregation function. Including the following:
1. Support input parameters `sample_rate` and `max_bucket_num`
2. Add UT and regression test
3. Add documentation
4. Optimize function implementation logic
Parameter description：
- `sample_rate`：Optional. The proportion of sample data used to generate the histogram. The default is 0.2.
- `max_bucket_num`：Optional. Limit the number of histogram buckets. The default value is 128.
---
Example：
```
MySQL [test]> SELECT histogram(c_float) FROM histogram_test;
+-------------------------------------------------------------------------------------------------------------------------------------+
| histogram(`c_float`) |
+-------------------------------------------------------------------------------------------------------------------------------------+
| {"sample_rate":0.2,"max_bucket_num":128,"bucket_num":3,"buckets":[{"lower":"0.1","upper":"0.1","count":1,"pre_sum":0,"ndv":1},...]} |
+-------------------------------------------------------------------------------------------------------------------------------------+
MySQL [test]> SELECT histogram(c_string, 0.5, 2) FROM histogram_test;
+-------------------------------------------------------------------------------------------------------------------------------------+
| histogram(`c_string`) |
+-------------------------------------------------------------------------------------------------------------------------------------+
| {"sample_rate":0.5,"max_bucket_num":2,"bucket_num":2,"buckets":[{"lower":"str1","upper":"str7","count":4,"pre_sum":0,"ndv":3},...]} |
+-------------------------------------------------------------------------------------------------------------------------------------+
```
Query result description：
```
{
"sample_rate": 0.2,
"max_bucket_num": 128,
"bucket_num": 3,
"buckets": [
{
"lower": "0.1",
"upper": "0.2",
"count": 2,
"pre_sum": 0,
"ndv": 2
},
{
"lower": "0.8",
"upper": "0.9",
"count": 2,
"pre_sum": 2,
"ndv": 2
},
{
"lower": "1.0",
"upper": "1.0",
"count": 2,
"pre_sum": 4,
"ndv": 1
}
]
}
```
Field description：
- sample_rate：Rate of sampling
- max_bucket_num：Limit the maximum number of buckets
- bucket_num：The actual number of buckets
- buckets：All buckets
- lower：Upper bound of the bucket
- upper：Lower bound of the bucket
- count：The number of elements contained in the bucket
- pre_sum：The total number of elements in the front bucket
- ndv：The number of different values in the bucket
> Total number of histogram elements = number of elements in the last bucket(count) + total number of elements in the previous bucket(pre_sum).
MySQL [db]> SELECT SUM(a.r[1]) as active_user_num, SUM(a.r[2]) as active_user_num_1day, SUM(a.r[3]) as active_user_num_3day, SUM(a.r[4]) as active_user_num_7day FROM ( SELECT user_id, retention( day = '2022-11-01', day = '2022-11-02', day = '2022-11-04', day = '2022-11-07') as r FROM login_event WHERE (day >= '2022-11-01') AND (day <= '2022-11-21') GROUP BY user_id ) a;
ERROR 1105 (HY000): errCode = 2, detailMessage = sum requires a numeric parameter: sum(%element_extract%(a.r, 1))
1. remove FE config `enable_array_type`
2. limit the nested depth of array in FE side.
3. Fix bug that when loading array from parquet, the decimal type is treated as bigint
4. Fix loading array from csv(vec-engine), handle null and "null"
5. Change the csv array loading behavior, if the array string format is invalid in csv, it will be converted to null.
6. Remove `check_array_format()`, because it's logic is wrong and meaningless
7. Add stream load csv test cases and more parquet broker load tests
