The changes of this PR for JdbcOracleClient are as follows:
#### bug fixes:
1. Fix the problem that if there is an approximate table name for Schema synchronization with a table name with `/` characters, the synchronization Column will be confused
2. Fix the NPE problem of metadata synchronization after enabling lower_case_table_names configuration
#### improvement:
1. Modify the method of synchronizing Oracle User to Doris Database mapping, use `metadata.getSchemas` instead of `SELECT DISTINCT OWNER FROM all_tables`
2. When synchronizing metadata, change `null` at the catalog level to `conn.getcatalog`
The data type `NUMBER(p,s)` of oracle has some different of doris decimal type in semantics.
For Oracle Number(p,s) type：
1.
if s<0 , it means this is an Interger. This `NUMBER(p,s)` has (p+|s| ) significant digit,
and rounding will be performed at s position.
eg: if we insert 1234567 into `NUMBER(5,-2)` type, then the oracle will store 1234500. In this case,
Doris will use
int type (`TINYINT/SMALLINT/INT/.../LARGEINT`).
2. if s>=0 && s<p , it just like doris Decimal(p,s) behavior.
3. if s>=0 && s>p, it means this is a decimal(like 0.xxxxx).
p represents how many digits can be left to the left after the decimal point,
the figure after the decimal point s will be rounded. eg: we can not insert 0.0123456 into `NUMBER(5,7)` type,
because there must be two zeros on the right side of the decimal point,
we can insert 0.0012345 into `NUMBER(5,7)` type. In this case, Doris will use `DECIMAL(s,s)`
4. if we don't specify p and s for `NUMBER(p,s)` like `NUMBER`,
the p and s of `NUMBER` are uncertain. In this case, doris can not determine p and s,
so doris can not determine data type.
