[Improvement]: Change the cost for reading and writing file to the same when evaluating the cost for optimizing partition

[klion26]

Search before asking

• [X] I have searched in the issues and found no similar issues.

What would you like to be improved?

Currently, the cost for writing a file is treated as 3 times as reading, when optimizing, we need to read/write all columns, both have essentially the same overheads.

How should we improve?

change the cost for writing as the same as reading

Are you willing to submit PR?

• [X] Yes I am willing to submit a PR!

Subtasks

No response

Code of Conduct

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