Remember the last page of an index insert if it's the rightmost leaf page. If the next entry belongs on and can fit in the remembered page, insert the new entry there as long as we can get a lock on the page. Otherwise, fall back on the more expensive method of searching for the right place to insert the entry.
This provides a performance improvement for the common case where an index entry is for monotonically increasing or nearly monotonically increasing value such as an identity field or a current timestamp.
Pavan Deolasee Reviewed by Claudio Freire, Simon Riggs and Peter Geoghegan
2b27273435 Optimize btree insertions for common case of increasing values
src/backend/access/nbtree/nbtinsert.c | 138 +++++++++++++++---
src/test/regress/expected/indexing.out | 249 +++++++++++++++++++++++++++++++++
src/test/regress/sql/indexing.sql | 116 +++++++++++++++
3 files changed, 484 insertions(+), 19 deletions(-)