On Mon, May 17, 2004 at 10:09:32 +0200,
Oliver Fromme <olli@lurza.secnetix.de> wrote:
>
> I can't believe that's true. That would be a serious show-
> stopper bug in PostgreSQL, in my opinion. The documentation
> does not mention anywhere that periodically dropping and re-
> creating indices might be necessary. In fact, in chapter
> 11.8 it specifically says "indexes in PostgreSQL do not need
> maintenance and tuning".
There was a problem with reclaming dead space in btrees before 7.4.
If old data was deleted and new data added with the key for the new
date always increasing (or always decreasing), then the freed up
pages would never get reused. Changes were mage in 7.4 to alleviate
this problem. The developers weren't sure if there were still some
usage patterns that could result in a lot of wasted space. My memory
is that there was an O(n) upper bound on the space used now, but I
might be wrong about that.