Re: [pgsql-advocacy] MySQL to PostgreSQL, was ENUM type

On Jul 27, 2005, at 9:53 PM, Tom Lane wrote:

> Gregory Youngblood <pgcluster(at)netio(dot)org> writes:
>
>> ... the problem is unsigned bigint in mysql to postgresql.
>> There's not another larger integer size that can be used that would
>> allow the 18446744073709551615 (is that the max value?) max value
>> available in mysql. Or am I missing something?
>>
>
> You'd have to translate that to NUMERIC, which would work but would
> take a bit of a performance hit ...

The most common places I've seen unsigned bigint used have been
primary keys for tables where the counter is expected to basically
grow forever. I've also seen it used to store unique user id numbers
instead of varchar fields. In both of those cases, the number is used
as a key, either alone or with another field, in an index. Would
there be much of a performance hit for that type of use? I can image
the biggest performance hit being mathematical calculations, such as
sum(), etc. Or would the performance hit be across the board?

Greg