Database Size?

[Frank Schima]

On Aug 21, 2004, at 1:08 AM, Ruslan Zasukhin wrote:

> On 8/21/04 6:53 AM, "Frank Schima" <frank-list2 at mindstarprods.com> 
> wrote:
>
>> Really! This is very interesting. Do you remember that I had a problem
>> with a database becoming corrupt because the segment size was too
>> small? I was trying to use 128 *bytes* and I saw the problem. I have
>> used 512 bytes successfully though. It's too bad because 4KB becomes
>> the smallest record size then for a single table database.
>>
>> So I guess there is no way to support smaller than 4kB segment size?
>
> You can specify less size.
>
> And this ALSO will reduce the initial size of db.
> Db with 2KB with be 2 times less than db with 4KB.
>
> I have to think more...my words are above are wrong.
>
> We can have db.segment e.g. 1KB.
> So on one physical page of OS file will be located 4 Valentina 
> segments.
> This still will work.
>
> And if we want to read 1 Valentina segment then OS will load into RAM 
> all 4
> segments. Because they are on single page of OS file.
>
> I don't know why there was problems with so small segment size.
> Probably because FAT also is built on segments, and if you have 128 
> bytes
> segment, then one FAT page can keep refs of only 32 data-pages. 
> Probably
> this cause very fast some problems.
>
> I remember that with size of segment is based some limit on size of db.
> Hmm, we have never talk about this...because limit this limit is very 
> high
> even for 1-4KB. I need refresh my memory on this.

I was looking back at my small segment size project. Here is the weird 
thing. When I set the segment size to 128 bytes and 1 file, then it 
creates a corrupted database. But when I change it to a 4 file 
database, then it was ok! For a single file database, I had to set the 
segment size to 4 kB (or larger) in order to create a database that was 
not corrupt. I had sent you the project and file before, let me know if 
you need them again.


-Frank