The datatype of the column inside a existing table is of type Char(4). Now, can there be any impact while choosing that row basically boost the column length to express 10.

In my opinion whenever you increase a char area, extra spaces are put into complete individuals not already filled, in certain databases if not completely.

This might impact some programs which were not expecting this behavior, and could cause some output issues if extra whitespace isn't being trimmed.

I suppose substring-like functions (and individuals based on string length) can also be affected as the duration of your string has transformed.

Why don't you varchar2(10)? Are you currently really while using entire string for each record?

Inside a vacuum tthere shouldn't be real impact of growing the the VARCHAR2 datatype on the column.

Unlike CHAR that are right-padded with blanks, a bigger VARCHAR2 size won't noticeably change any existing records.

However, as others have pointed out, what we're not able to predict is exactly what occur in any layer you've on the top from the database which might depend around the column as being a particular size but I am sure you can answer that much better than us.

Be cautious though, it isn't very easy creating a VARCHAR2 column more compact again. Even when your computer data is at the brand new restrictions Oracle will require the column being empty. Your best choice would be to export the rows and rebuild the table or shuffle posts (create new column, migrate values, drop old column).

"While choosing that row"

In individuals cases, the only real impact you may be suffering is unpredicted truncation. From the once asking towards the DB2 specialist during my company exactly what the indicator value "-2" meant. He did not know.

But when you have any query anywhere which involves "LENGTH(yourcolumnname)", also it works out that the code depends on that LENGTH() invocation not to return something > 4, then obviously you are in danger.