Thread: pgsql: Fix past pd_upper write in ginRedoRecompress()
Fix past pd_upper write in ginRedoRecompress() ginRedoRecompress() replays actions over compressed segments of posting list in-place. However, it might lead to write past pg_upper, because intermediate state during playing the changes can take more space than both original state and final state. This commit fixes that by refuse from in-place modification. Instead page tail is copied once modification is started, and then it's used as the source of original segments. Backpatch to 9.4 where posting list compression was introduced. Reported-by: Sivasubramanian Ramasubramanian Discussion: https://postgr.es/m/1536091151804.6588%40amazon.com Author: Alexander Korotkov based on patch from and ideas by Sivasubramanian Ramasubramanian Review: Sivasubramanian Ramasubramanian Backpatch-through: 9.4 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/5f08accdad2b03e0107bdc73d48783a01fe51c8c Modified Files -------------- src/backend/access/gin/ginxlog.c | 80 +++++++++++++++++++++++++++++----------- 1 file changed, 59 insertions(+), 21 deletions(-)