This enhancement shall extend existing logic for SHOW PARTITIONS FROM to include: -
Limit/Offset
Where [partition name only] [equal operator and like operator]
Order by [partition name only]
Issue Number: close#27834
* [regression-test](Variant) Add more cases related to schema changes
And fix bugs about schema change for variant:
fix bug schema change crash on doing schema change with tablet schema that contains extracted columns
If specified, got a column of constant. otherwise an incremental series like it always be.
mysql> select * from numbers("number" = "5", "const_value" = "-123");
+--------+
| number |
+--------+
| -123 |
| -123 |
| -123 |
| -123 |
| -123 |
+--------+
5 rows in set (0.11 sec)
If the original data is：
```sql
+-----------------------------------------------------+
| s_info |
+-----------------------------------------------------+
| {"s_id": 2, "s_name": "nereids", "s_address": "20"} |
| {"s_id": 1, "s_name": "doris", "s_address": "18"} |
+-----------------------------------------------------+
```
In the original logic, the struct type data exported to a csv file format did not contain column names,like
```
{2, "nereids", "20"}
{1, "doris", "18"}
```
This pr do not need to be merged into branch-2.0
refactor:
1. split InsertIntoTableCommand into three sub command
- InsertIntoTableCommand
- InsertOverwriteTableCommand
- BatchInsertIntoTableCommand
feature:
1. support DEFAULT keywords in values list
2. support empty values list
3. support temporary partition
4. support insert into values in txn model
fix:
1. should start transaction before release read lock on target table
* [DNM](decimal) use new way for decimal arithmetic precision promotion
* [improvement](decimal) [DNM](decimal) use new way for decimal arithmetic precision promotion
1. [DNM](decimal) use new way for decimal arithmetic precision promotion
2. throw exception if it overflows for decimal arithmetics
3. throw exception if it overflows when casting among number types
* fix compile error of gcc
* improvement
---------
Co-authored-by: morrySnow <morrysnow@126.com>
q1: "select * from ut_p temporary partitions(tp1) where val > 0"
in q1, temporary partition tp1 is scaned
q2: "select * from ut_p where val > 0"
in q2, temporary partition tp1 is not scaned.
1. max compute partition prune,
we just support filter mc partitions by '='，it can filter just one partition
to support multiple partition filter and range operator('>','<', '>='..), the partition prune should be supported.
2. add max compute row count cache and partitionValues cache
3. add max compute regression case
this change improves performance of tpch q20. on sf500, improved from 6.3sec to 1.1 sec
this change has no impaction on tpcds
when column stats is unknown,
the basic algorithm to estimate left semi join output row count is its left child output row count.
q1: "A left semi join B on A.x=B.x"
the output row is estimated as A.rowCount.
But the basic algorithm is not good to following pattern:
q2: "A left semi join filter(B) on A.x=B.x"
Because there is a filter on B, usually this left semi join also reduce the row count of A, and we estimate
the output of q2 as A.rowCount * Filter.rowCount/B.rowCount
