Subject Re: AW: [ib-support] FB crash
Author Helen Borrie
At 03:39 PM 08-05-02 +0200, you wrote:
> >The page_size has to be large enough to accommodate one row of your table
> >structure. Your two varchar(4000) columns on their own would require a
> >page_size of 8K. Add the other columns and we come out at 8224 bytes -
> >plus a few for page info data. So 8192 bytes is too small.
>helen, i have used varchar's bigger than the page size in some databases and
>never ran into problems so far. where does this limit come from? where is
>this documented? can i expect to run into problems? why doesn't the server
>throw a error if i create a record that is too big?
>could you please comment on this

Michael, I think you are right. <g> I can recall back some years creating
varchars of 32K, and that was when page_size was limited to 8K. Oh, and I
think I even remember Ann (?) recommending to use blobs rather than
varchars of such a size that a single record had to be distributed across
multiple pages.

I'm pretty convinced that the problem reported was not caused by the large
varchars directly but by corruption of shared memory space. The problem
started to occur after he added the two varchar(4000) columns so possibly
they were just lucky previously, when their record was only a couple of
hundred bytes.

Thanks for picking up on that.


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