On Fri, Jan 19, 2024 at 11:37 AM Tom Lane <tgl@xxxxxxxxxxxxx> wrote:
Ron Johnson <ronljohnsonjr@xxxxxxxxx> writes:
> On an RDMS which I used in the 1990s and 2000s, b-tree indices of sequences
> would get unbalanced, since every new leaf was added to the far right
> corner of the tree.
> Sure, they would auto-balance *to a degree* during node splits, but all
> those "far-right corner" inserts still left them pretty lopsided.
> Thus, they provided a utility which we could use to determine the
> lopsidedness, and thus decide when to rebuild an index.
> Does Postgresql keep b-tree indexes on sequences fully balanced? If not,
> how do I see how unbalanced they are? (Assume PG12+.)
As far as I know, we don't have a problem of that sort. Continued
insertions will eventually force a split of the root node, which will
rebalance the tree.
Thanks for the explanation.
