Re: [HACKERS] Re: [SQL] Column name's length

wieck(at)debis(dot)com (Jan Wieck) writes:
> What about building them from the tables OID plus the column
> numbers.

The parser doesn't know what OID will be assigned to the table at the
time it builds the names for the derived objects. I suppose we could
postpone the creation of these names until after the table OID is known,
but that looks like a rather large and risky change to be making at this
stage of the release cycle...

At this point I like Zalman's idea, which if I understood it properly
went like this:

1. If table and column name are short enough, use "table_column_key"
etc (so, no change in the cases that the system accepts now).

2. Otherwise, truncate table and/or column name to fit, leaving room for
a few extra characters that are made from a hash of the removed
characters. The result would look something like "tab_col_5927_key".

This still isn't a 100% solution, but it's probably a 99.5% solution
where the simple truncation idea would be maybe 95%. Not sure that
the additional coverage is worth making the names harder to predict
for a person, though.

regards, tom lane