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authorAndrew Gierth <rhodiumtoad@postgresql.org>2020-11-24 20:58:32 +0000
committerAndrew Gierth <rhodiumtoad@postgresql.org>2020-11-24 21:16:58 +0000
commit6dda057043df4a56683e8fa31a74737b63da4c47 (patch)
treed297deef8890d0383b1a8a3995f2d6f5ac3da8f6
parent340ae3cfb8f38a49664c0da3ff033346e92f0450 (diff)
downloadpostgresql-6dda057043df4a56683e8fa31a74737b63da4c47.tar.gz
postgresql-6dda057043df4a56683e8fa31a74737b63da4c47.zip
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
-rw-r--r--src/backend/executor/execAmi.c5
-rw-r--r--src/backend/optimizer/util/plancat.c2
-rw-r--r--src/include/nodes/pathnodes.h1
3 files changed, 8 insertions, 0 deletions
diff --git a/src/backend/executor/execAmi.c b/src/backend/executor/execAmi.c
index e2154ba86aa..0c10f1d35c2 100644
--- a/src/backend/executor/execAmi.c
+++ b/src/backend/executor/execAmi.c
@@ -417,6 +417,11 @@ ExecSupportsMarkRestore(Path *pathnode)
{
case T_IndexScan:
case T_IndexOnlyScan:
+ /*
+ * Not all index types support mark/restore.
+ */
+ return castNode(IndexPath, pathnode)->indexinfo->amcanmarkpos;
+
case T_Material:
case T_Sort:
return true;
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c
index 25545029d7a..3c7f3087a8b 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -275,6 +275,8 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
info->amhasgettuple = (amroutine->amgettuple != NULL);
info->amhasgetbitmap = amroutine->amgetbitmap != NULL &&
relation->rd_tableam->scan_bitmap_next_block != NULL;
+ info->amcanmarkpos = (amroutine->ammarkpos != NULL &&
+ amroutine->amrestrpos != NULL);
info->amcostestimate = amroutine->amcostestimate;
Assert(info->amcostestimate != NULL);
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index 485d1b06c91..8d1ad3339f2 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -864,6 +864,7 @@ struct IndexOptInfo
bool amhasgettuple; /* does AM have amgettuple interface? */
bool amhasgetbitmap; /* does AM have amgetbitmap interface? */
bool amcanparallel; /* does AM support parallel scan? */
+ bool amcanmarkpos; /* does AM support mark/restore? */
/* Rather than include amapi.h here, we declare amcostestimate like this */
void (*amcostestimate) (); /* AM's cost estimator */
};