Fix incorrect block accounting in TID Range Scans
heapgettup_advance_block() (or heapgettup() and heapgettup_pagemode() in
versions before v16) would incorrectly decrement rs_numblocks when
advancing to the next block. Ordinarily this was fine, but if the TID
Range scan plan was used by a scrollable cursor and the cursor was fetched
backwards enough to result in another block being required, then
rs_numblocks may have reached 0 prematurely resulting in the scan ending
prematurely.
Reported-by: Jeff Davis <pgsql@j-davis.com>
Author: Ewan Young <kdbase.hack@gmail.com>
Author: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/6b50233fcc0f7d6f4845f083777fa9702d9612e4.camel@j-davis.com
Backpatch-through: 14
Branch
------
REL_16_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/6ceac2e125025ca9e392a851a979807ee4dba176
Modified Files
--------------
src/backend/access/heap/heapam.c | 20 +++++++++++---------
src/test/regress/expected/tidrangescan.out | 26 ++++++++++++++++++++++++++
src/test/regress/sql/tidrangescan.sql | 12 ++++++++++++
3 files changed, 49 insertions(+), 9 deletions(-)
