修复vacuum在调用UBTreeVacuumPage时可能出现的不回收问题

src/gausskernel/storage/access/ubtree/ubtpage.cpp

@@ -165,7 +165,7 @@ Buffer UBTreeGetRoot(Relation rel, int access)
             BufferDesc *buf = GetBufferDescriptor(rootbuf - 1); // caveat for GetBufferDescriptor for -1!
             valid = PinBuffer(buf, NULL);
             if (valid && TryLockBuffer(rootbuf, BT_READ, false)) {
-                isRootCacheValid = buf->tag.forkNum == MAIN_FORKNUM &&
+                isRootCacheValid = (!IS_EXRTO_STANDBY_READ) && (buf->tag.forkNum == MAIN_FORKNUM) &&
                     RelFileNodeEquals(buf->tag.rnode, rel->rd_node) && (buf->tag.blockNum == rootblkno);
                 if (!isRootCacheValid) {
                     UnlockReleaseBuffer(rootbuf);

src/gausskernel/storage/access/ubtree/ubtree.cpp

@@ -905,6 +905,11 @@ restart:
         if (minoff <= maxoff) {
             stats->num_index_tuples += maxoff - minoff + 1;
         }
+        
+        if(vstate->cycleid !=0 && opaque->btpo_cycleid == vstate->cycleid
+           && !(opaque->btpo_flags & BTP_SPLIT_END) && !P_RIGHTMOST(opaque) && opaque->btpo_next < origBlkno){
+            recurseTo = opaque->btpo_next;
+        }
     }
 
     if (deleteNow) {