Thread: pgsql: Fix handling of NULL distances in KNN-GiST
Fix handling of NULL distances in KNN-GiST In order to implement NULL LAST semantic GiST previously assumed distance to the NULL value to be Inf. However, our distance functions can return Inf and NaN for non-null values. In such cases, NULL LAST semantic appears to be broken. This commit fixes that by introducing separate array of null flags for distances. Backpatch to all supported versions. Discussion: https://postgr.es/m/CAPpHfdsNvNdA0DBS%2BwMpFrgwT6C3-q50sFVGLSiuWnV3FqOJuQ%40mail.gmail.com Author: Alexander Korotkov Backpatch-through: 9.4 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/02f90879e75b3d4ccdba1ec7c3cad6af08dff77d Modified Files -------------- src/backend/access/gist/gistget.c | 70 ++++++++++++++++++++---------- src/backend/access/gist/gistscan.c | 25 +++++++++-- src/backend/access/index/indexam.c | 14 ++++-- src/backend/access/spgist/spgscan.c | 1 + src/include/access/genam.h | 4 +- src/include/access/gist_private.h | 26 +++++++++-- src/test/regress/expected/create_index.out | 2 +- 7 files changed, 106 insertions(+), 36 deletions(-)