nbtree: Move fastpath NULL descent stack assertion. Commit 074251db added an assertion that verified the fastpath/rightmost page insert optimization's assumption about free space: There should always be enough free space on the page to insert the new item without splitting the page. Otherwise, we end up using the "concurrent root page split" phony/fake stack path in _bt_insert_parent(). This does not lead to incorrect behavior, but it is likely to be far slower than simply using the regular _bt_search() path. The assertion catches serious performance bugs that would probably take a long time to detect any other way.
It seems much more natural to make this assertion just before the point that we generate a fake/phony descent stack. Move the assert there. This also makes _bt_insertonpg() a bit more readable. Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/39eabec90451d8badbba9b3e938d6d05432a0517 Modified Files -------------- src/backend/access/nbtree/nbtinsert.c | 46 +++++++++++++++-------------------- 1 file changed, 20 insertions(+), 26 deletions(-)
