diff --git a/src/backend/access/nbtree/README b/src/backend/access/nbtree/README
index 40f09e397ea453ff78a9db98d1932b60d055568d..bf5bc38273d96d5f3ab401cb5b74e69da1c7b811 100644
--- a/src/backend/access/nbtree/README
+++ b/src/backend/access/nbtree/README
@@ -438,14 +438,17 @@ location of the root page --- both the true root and the current effective
 root ("fast" root).  To avoid fetching the metapage for every single index
 search, we cache a copy of the meta-data information in the index's
 relcache entry (rd_amcache).  This is a bit ticklish since using the cache
-implies following a root page pointer that could be stale.  We require
-every metapage update to send out a SI "relcache inval" message on the
-index relation.  That ensures that each backend will flush its cached copy
-not later than the start of its next transaction.  Therefore, stale
-pointers cannot be used for longer than the current transaction, which
-reduces the problem to the same one already dealt with for concurrent
-VACUUM --- we can just imagine that each open transaction is potentially
-"already in flight" to the old root.
+implies following a root page pointer that could be stale.  However, a
+backend following a cached pointer can sufficiently verify whether it
+reached the intended page; either by checking the is-root flag when it
+is going to the true root, or by checking that the page has no siblings
+when going to the fast root.  At worst, this could result in descending
+some extra tree levels if we have a cached pointer to a fast root that is
+now above the real fast root.  Such cases shouldn't arise often enough to
+be worth optimizing; and in any case we can expect a relcache flush will
+discard the cached metapage before long, since a VACUUM that's moved the
+fast root pointer can be expected to issue a statistics update for the
+index.
 
 The algorithm assumes we can fit at least three items per page
 (a "high key" and two real data items).  Therefore it's unsafe
diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c
index 49c084a5abeb23297c99c0dda0a58b2bc6d81a59..91407499981a38ba8b4283c04fa0a8b99332fd4b 100644
--- a/src/backend/access/nbtree/nbtinsert.c
+++ b/src/backend/access/nbtree/nbtinsert.c
@@ -21,7 +21,6 @@
 #include "miscadmin.h"
 #include "storage/lmgr.h"
 #include "storage/predicate.h"
-#include "utils/inval.h"
 #include "utils/tqual.h"
 
 
@@ -868,13 +867,9 @@ _bt_insertonpg(Relation rel,
 
 		END_CRIT_SECTION();
 
-		/* release buffers; send out relcache inval if metapage changed */
+		/* release buffers */
 		if (BufferIsValid(metabuf))
-		{
-			if (!InRecovery)
-				CacheInvalidateRelcache(rel);
 			_bt_relbuf(rel, metabuf);
-		}
 
 		_bt_relbuf(rel, buf);
 	}
@@ -1963,10 +1958,6 @@ _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf)
 
 	END_CRIT_SECTION();
 
-	/* send out relcache inval for metapage change */
-	if (!InRecovery)
-		CacheInvalidateRelcache(rel);
-
 	/* done with metapage */
 	_bt_relbuf(rel, metabuf);
 
diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c
index c7c65a6a40d1a97ad755f713ffd6915ec82884f8..1e7885800138aabfa8f20a0d36cbd79d45c0b66c 100644
--- a/src/backend/access/nbtree/nbtpage.c
+++ b/src/backend/access/nbtree/nbtpage.c
@@ -28,7 +28,6 @@
 #include "storage/indexfsm.h"
 #include "storage/lmgr.h"
 #include "storage/predicate.h"
-#include "utils/inval.h"
 #include "utils/snapmgr.h"
 
 
@@ -246,12 +245,6 @@ _bt_getroot(Relation rel, int access)
 
 		END_CRIT_SECTION();
 
-		/*
-		 * Send out relcache inval for metapage change (probably unnecessary
-		 * here, but let's be safe).
-		 */
-		CacheInvalidateRelcache(rel);
-
 		/*
 		 * swap root write lock for read lock.	There is no danger of anyone
 		 * else accessing the new root page while it's unlocked, since no one
@@ -1545,12 +1538,10 @@ _bt_pagedel(Relation rel, Buffer buf, BTStack stack)
 
 	END_CRIT_SECTION();
 
-	/* release metapage; send out relcache inval if metapage changed */
+	/* release metapage */
 	if (BufferIsValid(metabuf))
-	{
-		CacheInvalidateRelcache(rel);
 		_bt_relbuf(rel, metabuf);
-	}
+
 	/* can always release leftsib immediately */
 	if (BufferIsValid(lbuf))
 		_bt_relbuf(rel, lbuf);
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index b7f9e2e1608056594dddb2b78f62a05224ee14e3..1da9548d57b54ef0f670e479eafd56c8312a146a 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -148,14 +148,6 @@ btbuild(PG_FUNCTION_ARGS)
 	}
 #endif   /* BTREE_BUILD_STATS */
 
-	/*
-	 * If we are reindexing a pre-existing index, it is critical to send out a
-	 * relcache invalidation SI message to ensure all backends re-read the
-	 * index metapage.	We expect that the caller will ensure that happens
-	 * (typically as a side effect of updating index stats, but it must happen
-	 * even if the stats don't change!)
-	 */
-
 	/*
 	 * Return statistics
 	 */