[Improvement] change default config

[JNSimba]

Proposed changes

Issue Number: close #xxx

Problem Summary:

In some scenarios, such as when reading a large amount of data, the default parameters of the Connector may cause failure, such as timeout, memory limit, etc.
So here we improve the default parameter values to ensure that they can be used out of the box as much as possible.

Checklist(Required)

1. Does it affect the original behavior: (Yes/No/I Don't know)
2. Has unit tests been added: (Yes/No/No Need)
3. Has document been added or modified: (Yes/No/No Need)
4. Does it need to update dependencies: (Yes/No)
5. Are there any changes that cannot be rolled back: (Yes/No)

Further comments

If this is a relatively large or complex change, kick off the discussion at [email protected] by explaining why you chose the solution you did and what alternatives you considered, etc...