>>>>> "Tom" == Tom Lane <t...@sss.pgh.pa.us> writes:
Tom> Oh, sorry, I misread your comment to be that you wanted to add a
Tom> field to IndexAmRoutine. You're right, the real issue here is that
Tom> ExecSupportsMarkRestore lacks any convenient access to the needed
Tom> info, and we need to add a bool to IndexOptInfo to fix that.
Tom> I don't see any compelling reason why you couldn't add the field
Tom> at the end in the back branches; that's what we usually do to
Tom> avoid ABI breaks. Although actually (counts fields...) it looks
Tom> like there's at least one pad byte after amcanparallel, so you
Tom> could add a bool there without any ABI consequence, resulting in a
Tom> reasonably natural field order in all branches.
I guess that's close enough; this should suffice then.
--
Andrew (irc:RhodiumToad)
diff --git a/src/backend/executor/execAmi.c b/src/backend/executor/execAmi.c
index e2154ba86a..0c10f1d35c 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 52c01eb86b..3e94256d34 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -284,6 +284,8 @@ 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 abe6f570e3..5a10c1855d 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 */
};
