Konstantin Karpov wrote:

> > Does support fixed quantity of rows in a table (deleting of 
> older rows) > guarantee that the table file size won't grow?
> 
>       Sorry, my previous question wasn't correct. Not table 
> file size, but physical table size.

The same number of rows does not necessarily mean the exact
number of space used.
Space is used in pages (8KB).
Rows usually differ in length (see explanations about internally
used number of bytes in the reference manual
http://www.sapdb.org/htmhelp/ff/baaba8d55a11d2a97400a0c9449261/frameset.htm
if for (VAR)CHAR there is given + 2 / + 3 it has to be pointed out,
that the length will depend on the actual length of the character value
and not of the maximum possible character count).

If we assume a page is filled completely, then two rows
will be deleted somewhere in the middle --> the page is not free,
but filled in a way that no putting-together with the left or right page
would result in a free page, then there is space waisted.
And if you add 2 rows (--> the number of rows is exactly the same
as it was in the beginning) it depends on the key, if this space
will be reused or somewhere else in the tree there is used some
free space or if a new, additional page is needed for this table.

but after some time usually there is some number of pages
which will not vary much for this table any more (if the rows
do not change in number or size)

Elke
SAP Labs Berlin
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