Refactor nbtree insertion scankeys. Use dedicated struct to represent nbtree insertion scan keys. Having a dedicated struct makes the difference between search type scankeys and insertion scankeys a lot clearer, and simplifies the signature of several related functions. This is based on a suggestion by Andrey Lepikhov.
Streamline how unique index insertions cache binary search progress. Cache the state of in-progress binary searches within _bt_check_unique() for later instead of having callers avoid repeating the binary search in an ad-hoc manner. This makes it easy to add a new optimization: _bt_check_unique() now falls out of its loop immediately in the common case where it's already clear that there couldn't possibly be a duplicate. The new _bt_check_unique() scheme makes it a lot easier to manage cached binary search effort afterwards, from within _bt_findinsertloc(). This is needed for the upcoming patch to make nbtree tuples unique by treating heap TID as a final tiebreaker column. Unique key binary searches need to restore lower and upper bounds. They cannot simply continue to use the >= lower bound as the offset to insert at, because the heap TID tiebreaker column must be used in comparisons for the restored binary search (unlike the original _bt_check_unique() binary search, where scankey's heap TID column must be omitted). Author: Peter Geoghegan, Heikki Linnakangas Reviewed-By: Heikki Linnakangas, Andrey Lepikhov Discussion: https://postgr.es/m/cah2-wzme6ahudk9ndwbf4k3hjwxzbx3+umc7mh7+wdrkcrt...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/e5adcb789d80ba565ccacb1ed4341a7c29085238 Modified Files -------------- contrib/amcheck/verify_nbtree.c | 52 ++--- src/backend/access/nbtree/README | 29 +-- src/backend/access/nbtree/nbtinsert.c | 400 +++++++++++++++++++--------------- src/backend/access/nbtree/nbtpage.c | 12 +- src/backend/access/nbtree/nbtsearch.c | 227 +++++++++++++------ src/backend/access/nbtree/nbtsort.c | 8 +- src/backend/access/nbtree/nbtutils.c | 94 +++----- src/backend/utils/sort/tuplesort.c | 16 +- src/include/access/nbtree.h | 78 +++++-- 9 files changed, 529 insertions(+), 387 deletions(-)
