Обсуждение: 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 ------ REL_11_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/d807200b4a73a100cb8f41ee2f3ff1e2507647b8 Modified Files -------------- src/backend/access/gist/gistget.c | 77 +++++++++++++++++++++++++------------- src/backend/access/gist/gistscan.c | 25 +++++++++++-- src/include/access/gist_private.h | 26 +++++++++++-- 3 files changed, 95 insertions(+), 33 deletions(-)