At 05:55 PM 3/3/98 +0100, alessandro.forcina@dianos.it wrote:
>... it was the only process running...
>And the messages in errlog.log are self-explicative.
>I admit it could have been a pathological situation, due to the fact that:
>  1) The table is 480696 pages and  ~3000000 rows big.
>  2) An sql script deleted ~2600000 rows from the table without modifying
>it
>     (so the freed space wasn't reclaimed)

Ok, I did a little more playing around.  Both 6.4 and OpenIngres will log
the actions of MODIFY TO MERGE.  Since MODIFY TO MERGE is an internal
reorganization in place, it must be logged so that any partially
completed merge can be undone (if it aborts) or redone (for fast-commit).

It seems that MODIFY TO MERGE is one of the situations where OpenIngres
logs more data than 6.4 did.  OI is logging about 8-9 K per index page
cleaned up (2 bi's, 2 ai, and some housekeeping);  while 6.4 is logging
about 6 K per index page (3 bi's and some housekeeping).  The extra logging
may be related to OI's freespace management;  I did not attempt to analyze
it sufficiently to find out.

In your particular instance a MODIFY TO BTREE would have been a better idea.

Karl R. Schendel, Jr.
K/B Computer Associates   schendel@kbcomputer.com
Ingres and Unix Expertise

Ingres Q & A

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