Fix handling of empty uncompressed posting list pages in GIN
PostgreSQL 9.4 introduces posting list compression in GIN. This feature
supports online upgrade, so that after pg_upgrade uncompressed posting
lists are compressed on-the-fly. Underlying code appears to always
expect at least one item on uncompressed posting list page. But there
could be completely empty pages, because VACUUM never deletes leftmost
and rightmost pages from posting trees. This commit fixes that.
Reported-by: Sivasubramanian Ramasubramanian
Discussion: https://postgr.es/m/1531867212836.63354%40amazon.com
Author: Sivasubramanian Ramasubramanian, Alexander Korotkov
Backpatch-through: 9.4
Branch
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REL9_6_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/44b550e0d9a5b3e4aba0211e7654b70e4f78b079
Modified Files
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src/backend/access/gin/gindatapage.c | 20 ++++++++++++--------
src/backend/access/gin/ginxlog.c | 27 +++++++++++++++++++++------
2 files changed, 33 insertions(+), 14 deletions(-)