bp #42882#43246#43336
We pick these PRs together because they all fix one problem and if not
do so, the regression test won't be passed.
---------
Co-authored-by: Sun Chenyang <csun5285@gmail.com>
Co-authored-by: qidaye <luen@selectdb.com>
pick from master #42576
intro by #39316. it want to fix a problem intro by #36699. but forgot to
remove all wrong code in #36699.
after #39316, we should not set offset on exchange, when the exchange is
on the top of a limit with offset.
Reverts apache/doris#42255
We have found that after closing the connection pool, there will be
class loading problems and connection release problems for some data
sources. We will remove this function first and re-add it after solving
and testing it completely.
```
insert into t1 (k1, k2, v1) value(1, '', 2);
delete form t1 where k1 = 1 and k2 = '';
alter table modify column v1 string
select * from t1 // expect 0 rows in return, but get 1 row.
```
…cs (#41989)
before this pr: use ! or not in or condition when table has been
analyzed we will meet
```
SELECT
count(1)
FROM
table_30_un_pa_ke_pr_di4
where
col_int_undef_signed_not_null < -128
or not array_contains(col_array_bigint__undef_signed, col_int_undef_signed_not_null);
ERROR 1105 (HY000): errCode = 2, detailMessage = Not-predicate meet unexpected child:
array_contains(col_array_bigint__undef_signed, cast(col_int_undef_signed_not_null as BIGINT))
```
## Proposed changes
Issue Number: close #xxx
<!--Describe your changes.-->
pick (#41992)
We initially introduced jdbc connection pool to improve the connection
performance of jdbc catalog, but we always found that connection pool
would bring some unexpected errors, so we chose to add a catalog
property: `enable_connection_pool` to choose whether to enable the jdbc
connection pool of jdbc catalog, and the default false.However, the
created catalog will still open the connection pool when it is upgraded,
and only the newly created catalog will be false
And we conducted performance tests on this, the performance loss is
within the expected range.
- Enable connection pool: mysqlslap -uroot -h127.0.0.1 -P9030
--concurrency=1 --iterations=100 --query='SELECT * FROM mysql.test.test
limit 1;' --create-schema=mysql --delimiter=";" --verbose
Benchmark
Average number of seconds to run all queries: 0.008 seconds
Minimum number of seconds to run all queries: 0.004 seconds
Maximum number of seconds to run all queries: 0.133 seconds
Number of clients running queries: 1
Average number of queries per client: 1
- Disable connection pool: mysqlslap -uroot -h127.0.0.1 -P9030
--concurrency=1 --iterations=100 --query='SELECT * FROM
mysql_no_pool.test.test limit 1;' --create-schema=mysql --delimiter=";"
--verbose
Benchmark
Average number of seconds to run all queries: 0.054 seconds
Minimum number of seconds to run all queries: 0.047 seconds
Maximum number of seconds to run all queries: 0.184 seconds
Number of clients running queries: 1
Average number of queries per client: 1
pick (#42102)
Add a variable `enable_jdbc_cast_predicate_push_down`, the default value
is false, which prohibits the pushdown of non-constant predicates with
type conversion and all predicates with implicit conversion. This change
can prevent the wrong predicates from being pushed down to the Jdbc data
source, resulting in query data errors, because the predicates with cast
were not correctly pushed down to the data source before. If you find
that the data is read correctly and the performance is better before
this change, you can manually set this variable to true
```
| Expression | Can Push Down |
|-----------------------------------------------------|---------------|
| column type equals const type | Yes |
| column type equals cast const type | Yes |
| cast column type equals const type | No |
| cast column type equals cast const type | No |
| column type not equals column type | No |
| column type not equals cast const type | No |
| cast column type not equals const type | No |
| cast column type not equals cast const type | No |
```
