diff --git a/src/pnl.c b/src/pnl.c
index 88f14c7f..d573c987 100644
--- a/src/pnl.c
+++ b/src/pnl.c
@@ -23,6 +23,13 @@ void pnl_free(pnl_t pnl) {
     osal_free(pnl - 1);
 }
 
+pnl_t pnl_clone(const pnl_t src) {
+  pnl_t pl = pnl_alloc(MDBX_PNL_ALLOCLEN(src));
+  if (likely(pl))
+    memcpy(pl, src, MDBX_PNL_SIZEOF(src));
+  return pl;
+}
+
 void pnl_shrink(pnl_t __restrict *__restrict ppnl) {
   assert(pnl_bytes2size(pnl_size2bytes(MDBX_PNL_INITIAL)) >= MDBX_PNL_INITIAL &&
          pnl_bytes2size(pnl_size2bytes(MDBX_PNL_INITIAL)) < MDBX_PNL_INITIAL * 3 / 2);
@@ -234,3 +241,18 @@ __hot __noinline size_t pnl_search_nochk(const pnl_t pnl, pgno_t pgno) {
     assert(!MDBX_PNL_ORDERED(it[0], pgno));
   return it - begin + 1;
 }
+
+size_t pnl_maxspan(const pnl_t pnl) {
+  size_t len = MDBX_PNL_GETSIZE(pnl);
+  if (len > 1) {
+    size_t span = 1, left = len - span;
+    const pgno_t *scan = MDBX_PNL_BEGIN(pnl);
+    do {
+      const bool contiguous = MDBX_PNL_CONTIGUOUS(*scan, scan[span], span);
+      span += contiguous;
+      scan += 1 - contiguous;
+    } while (--left);
+    len = span;
+  }
+  return len;
+}
diff --git a/src/pnl.h b/src/pnl.h
index c0b7d542..a329b9b2 100644
--- a/src/pnl.h
+++ b/src/pnl.h
@@ -45,10 +45,12 @@ typedef const pgno_t *const_pnl_t;
 #define MDBX_PNL_EDGE(pl) ((pl) + 1)
 #define MDBX_PNL_LEAST(pl) MDBX_PNL_FIRST(pl)
 #define MDBX_PNL_MOST(pl) MDBX_PNL_LAST(pl)
+#define MDBX_PNL_CONTIGUOUS(prev, next, span) ((next) - (prev)) == (span))
 #else
 #define MDBX_PNL_EDGE(pl) ((pl) + MDBX_PNL_GETSIZE(pl))
 #define MDBX_PNL_LEAST(pl) MDBX_PNL_LAST(pl)
 #define MDBX_PNL_MOST(pl) MDBX_PNL_FIRST(pl)
+#define MDBX_PNL_CONTIGUOUS(prev, next, span) (((prev) - (next)) == (span))
 #endif
 
 #define MDBX_PNL_SIZEOF(pl) ((MDBX_PNL_GETSIZE(pl) + 1) * sizeof(pgno_t))
@@ -83,6 +85,8 @@ MDBX_INTERNAL pnl_t pnl_alloc(size_t size);
 
 MDBX_INTERNAL void pnl_free(pnl_t pnl);
 
+MDBX_MAYBE_UNUSED MDBX_INTERNAL pnl_t pnl_clone(const pnl_t src);
+
 MDBX_INTERNAL int pnl_reserve(pnl_t __restrict *__restrict ppnl, const size_t wanna);
 
 MDBX_MAYBE_UNUSED static inline int __must_check_result pnl_need(pnl_t __restrict *__restrict ppnl, size_t num) {
@@ -144,3 +148,5 @@ MDBX_MAYBE_UNUSED static inline size_t pnl_search(const pnl_t pnl, pgno_t pgno,
 }
 
 MDBX_INTERNAL size_t pnl_merge(pnl_t dst, const pnl_t src);
+
+MDBX_MAYBE_UNUSED MDBX_NOTHROW_PURE_FUNCTION MDBX_INTERNAL size_t pnl_maxspan(const pnl_t pnl);