Properly check index mark/restore in ExecSupportsMarkRestore.
Previously this code assumed that all IndexScan nodes supported
mark/restore, which is not true since it depends on optional index AM
support functions. This could lead to errors about missing support
functions in rare edge cases of mergejoins with no sort keys, where an
unordered non-btree index scan was placed on the inner path without a
protecting Materialize node. (Normally, the fact that merge join
requires ordered input would avoid this error.)
Backpatch all the way since this bug is ancient.
Per report from Eugen Konkov on irc.
Discussion: https://postgr.es/m/87o8jn50be.fsf@news-spur.riddles.org.uk
Branch
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REL_10_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/321c87e5ca1a8a766a55ec4201099a37b9b0c68b
Modified Files
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src/backend/executor/execAmi.c | 5 +++++
src/backend/optimizer/util/plancat.c | 2 ++
src/include/nodes/relation.h | 1 +
3 files changed, 8 insertions(+)