Subject Re: Max. # of records in a table.
Author Michael Vilhelmsen
--- In, "Leyne, Sean" <Sean@B...> wrote:
> Michael,
> I am not aware of any way to calculate an absolute number.

I know - I'm not interesseted in an absolute number.
I'm more interesseted in a "hint" to how many records a table might hold.
As I read the text (the link) I can see, that there IS a difference
between how many records you teoretically can have in a table, and the
actual number of records.

If there was such a calculation, I could calculate a number (whcih I
know wouldn't be exact), and that would give me a hint.

I my opinion, I would rather have a number like 70.000.000 instead of
2 to the power of 32.

And what has been done in FB2 is great, but sinse a lot of our
custumers are using FB 1.5 and will be for some time to come, I just
wanted to know....


Thanks anyway

> I can say that prior to Firebird v2.0, each record had a 32 bit DB$KEY
> value. The 32 bits were not a true counter but a 'reference' value
> which incorporated information concerning the table number, the page
> number and then the page offset. All told the maximum size of a table
> worked out to be 30 to 40 GB in size.
> In v2.0 the DB$KEY has been increased to a 40 bit value. The additional
> bits were added to allow for a table to support more pages, thus more
> records. This means that the maximum size of a table (if my reasoning
> is right) should now be 30^8 or 40^8 GB in size.
> Sean