Improve the accuracy of sample stats collection. For non distribution columns, use
`n*d / (n - f1 + f1*n/N)`
where `f1` is the number of distinct values that occurred exactly once in our sample of n rows (from a total of N),
and `d` is the total number of distinct values in the sample.
For distribution columns, use `ndv(n) * fraction of tablets sampled` for NDV.
For very large tablet to sample, use limit to control the total lines to scan (for non key column only, because key column is sorted and will be inaccurate using limit).
1. not collect partition stats anymore
2. merge insert of stats
3. delete period collector since it is useless
4. remove enable_auto_sample
5. move some config related to stats to global session variable
Before this PR, when analyze a table, the insert count equals column count times 2
After this PR, insert count of analyze table would reduce to column count / insert_merge_item_count.
According to my test, when analyzing tpch lineitem, the insert sql count is 1
Doris is not responsible for managing snapshots, but it needs to clear all
snapshots before doing backup/restore regression testing, so a property is
added to indicate that existing snapshots need to be cleared when creating a
repo.
In addition, a regression test case for backup/restore has been added.
1. add checks and handling of sequence column in #21896 to insert statement in origin planner and Nereids planner.
2. disable drop sequence mapping column in schema change.
Hive partition columns' stats could be calculated from hive metastore data. Doesn't need to execute sql to get the stats.
This PR is using hive partition metadata to collect partition column stats.
### Before:
return errors when tvf queries an empty file or an error uri:
1. get parsed schema failed, empty csv file
2. Can not get first file, please check uri.
### Now:
we just return empty set when tvf queries an empty file or an error uri.
```sql
mysql> select * from s3(
"uri" = "https://error_uri/exp_1.csv",
"s3.access_key"= "xx",
"s3.secret_key" = "yy",
"format" = "csv") limit 10;
Empty set (1.29 sec)
```
