From Newsgroup: comp.databases.ingres

Monday, October 25, 2021, 1:48:29 PM, you wrote:

IAve recently had a btree table which had grown to 8025535 pages
with zero overflow. But after a modify it shrank to a little over 5000 pages.

My suspicion is that this table had grown to this size because it
is daily getting a few hundred thousand rows inserted and then
deleted. The key of the table is increasing and so deleted rows
on the pages are never reused.

Deleted rows on the associated data page should get reused. My
suspicion is MVCC is enabled on the database. That defeats the free
page management in Btrees.

Is there an easy way to determine the number of aemptyA pages? IAve
started experimenting with modify table to table_debug [with
table_option = 1|2|3], but IAm not seeing a smoking gun.

I have written various scripts over the years to join iifile_info and
iitables with the output from ls or dir, as appropriate.
Roy
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