diff --git a/src/box/index.h b/src/box/index.h
index 959ec461f215482006ebd4fa0ac4fba7f2c8868b..84e3dd9a282ce05c4436f55ccd9d12c9594e28e4 100644
--- a/src/box/index.h
+++ b/src/box/index.h
@@ -184,7 +184,7 @@ class Index: public Object {
 	virtual struct tuple *replace(struct tuple *old_tuple,
 				      struct tuple *new_tuple,
 				      enum dup_replace_mode mode) = 0;
-	virtual size_t memsize() const = 0;
+	virtual size_t bsize() const = 0;
 	/**
 	 * Create a structure to represent an iterator. Must be
 	 * initialized separately.
diff --git a/src/box/lua/index.cc b/src/box/lua/index.cc
index 0d2336a9d6115d330911ea765a11d2a8cd2dbd7b..ae010f76cd8b2afb7a90e06d48d0082a411675f6 100644
--- a/src/box/lua/index.cc
+++ b/src/box/lua/index.cc
@@ -48,10 +48,10 @@ check_index(uint32_t space_id, uint32_t index_id)
 }
 
 size_t
-boxffi_index_memsize(uint32_t space_id, uint32_t index_id)
+boxffi_index_bsize(uint32_t space_id, uint32_t index_id)
 {
        try {
-               return check_index(space_id, index_id)->memsize();
+               return check_index(space_id, index_id)->bsize();
        } catch (Exception *) {
                return (size_t) -1; /* handled by box.error() in Lua */
        }
diff --git a/src/box/lua/index.h b/src/box/lua/index.h
index adb76c27f0f16ff6bebcfc3d9a2d9603a2d0e526..ec176bb9634fd665a5dfec43925f35841b215b61 100644
--- a/src/box/lua/index.h
+++ b/src/box/lua/index.h
@@ -56,7 +56,7 @@ boxffi_index_iterator(uint32_t space_id, uint32_t index_id, int type,
 		      const char *key);
 
 size_t
-boxffi_index_memsize(uint32_t space_id, uint32_t index_id);
+boxffi_index_bsize(uint32_t space_id, uint32_t index_id);
 
 struct tuple*
 boxffi_iterator_next(struct iterator *itr);
diff --git a/src/box/lua/schema.lua b/src/box/lua/schema.lua
index 54b09f82a181f00b3357a2f8142fb7fbac1615bd..72d8458396acdf36d12737d57d77e5daf4c66cd2 100644
--- a/src/box/lua/schema.lua
+++ b/src/box/lua/schema.lua
@@ -23,7 +23,7 @@ ffi.cdef[[
     size_t
     boxffi_index_len(uint32_t space_id, uint32_t index_id);
     size_t
-    boxffi_index_memsize(uint32_t space_id, uint32_t index_id);
+    boxffi_index_bsize(uint32_t space_id, uint32_t index_id);
     struct tuple *
     boxffi_index_random(uint32_t space_id, uint32_t index_id, uint32_t rnd);
     struct tuple *
@@ -590,9 +590,9 @@ function box.schema.space.bless(space)
         end
         return tonumber(ret)
     end
-    -- index.memsize
-    index_mt.memsize = function(index)
-        local ret = builtin.boxffi_index_memsize(index.space_id, index.id)
+    -- index.bsize
+    index_mt.bsize = function(index)
+        local ret = builtin.boxffi_index_bsize(index.space_id, index.id)
         if ret == -1 then
             box.error()
         end
diff --git a/src/box/memtx_bitset.cc b/src/box/memtx_bitset.cc
index c5a9d89accb39bfc4e34b794f9439aec281dc8d8..64147c67ce0e235c06ffe0a0d00e0a9c48f273e9 100644
--- a/src/box/memtx_bitset.cc
+++ b/src/box/memtx_bitset.cc
@@ -110,7 +110,7 @@ MemtxBitset::size() const
 }
 
 size_t
-MemtxBitset::memsize() const
+MemtxBitset::bsize() const
 {
 	return 0;
 }
diff --git a/src/box/memtx_bitset.h b/src/box/memtx_bitset.h
index 85dc8affdfecf43e9481c9d3e886126d3306eb70..b6b0435aa5f9b14c6f29f9d4cc903db0b554e874 100644
--- a/src/box/memtx_bitset.h
+++ b/src/box/memtx_bitset.h
@@ -49,7 +49,7 @@ class MemtxBitset: public Index {
 				      struct tuple *new_tuple,
 				      enum dup_replace_mode mode);
 
-        virtual size_t memsize() const;
+	virtual size_t bsize() const;
 	virtual struct iterator *allocIterator() const;
 	virtual void initIterator(struct iterator *iterator,
 				  enum iterator_type type,
diff --git a/src/box/memtx_hash.cc b/src/box/memtx_hash.cc
index 93b7c63c658fc03fe83bbe273ef84301855cf7fa..f0fd2cc47583c389821d69f3f839c14829ec1ec6 100644
--- a/src/box/memtx_hash.cc
+++ b/src/box/memtx_hash.cc
@@ -230,7 +230,7 @@ MemtxHash::size() const
 }
 
 size_t
-MemtxHash::memsize() const
+MemtxHash::bsize() const
 {
         return matras_extents_count(&hash_table->mtable) * HASH_INDEX_EXTENT_SIZE;
 }
diff --git a/src/box/memtx_hash.h b/src/box/memtx_hash.h
index 711256981258c5506112543971f3f3255582250d..448b576a524ad488ee6139037f19415240dc3cf1 100644
--- a/src/box/memtx_hash.h
+++ b/src/box/memtx_hash.h
@@ -50,7 +50,7 @@ class MemtxHash: public Index {
 	virtual void initIterator(struct iterator *iterator,
 				  enum iterator_type type,
 				  const char *key, uint32_t part_count) const;
-	virtual size_t memsize() const;
+	virtual size_t bsize() const;
 
 protected:
 	struct light_index_core *hash_table;
diff --git a/src/box/memtx_rtree.cc b/src/box/memtx_rtree.cc
index 6a6bc037e723004651b53ebbf08cdb45d1380891..7106aa0f7cf7dae1a83d5fe0a0125962605fb522 100644
--- a/src/box/memtx_rtree.cc
+++ b/src/box/memtx_rtree.cc
@@ -185,9 +185,9 @@ MemtxRTree::size() const
 }
 
 size_t
-MemtxRTree::memsize() const
+MemtxRTree::bsize() const
 {
-        return rtree_used_size(&tree);
+	return rtree_used_size(&tree);
 }
 
 struct tuple *
diff --git a/src/box/memtx_rtree.h b/src/box/memtx_rtree.h
index c72732a9e514ceb3dfef3f5b76401c62e3e07aa8..f4aa0ca614827efc0f2b9f4104d1a1397db1a62d 100644
--- a/src/box/memtx_rtree.h
+++ b/src/box/memtx_rtree.h
@@ -46,7 +46,7 @@ class MemtxRTree: public Index
                                       struct tuple *new_tuple,
                                       enum dup_replace_mode mode);
 
-	virtual size_t memsize() const;
+	virtual size_t bsize() const;
 	virtual struct iterator *allocIterator() const;
 	virtual void initIterator(struct iterator *iterator,
                                   enum iterator_type type,
diff --git a/src/box/memtx_tree.cc b/src/box/memtx_tree.cc
index af0a95b2970a8b9860c3427b46fa822787cf37ae..cc418738db24fd309b50576c272650b80c01a941 100644
--- a/src/box/memtx_tree.cc
+++ b/src/box/memtx_tree.cc
@@ -204,7 +204,7 @@ MemtxTree::size() const
 }
 
 size_t
-MemtxTree::memsize() const
+MemtxTree::bsize() const
 {
 	return bps_tree_index_mem_used(&tree);
 }
diff --git a/src/box/memtx_tree.h b/src/box/memtx_tree.h
index 5102e2458c8140cbc48d5f430f04fe5bbb07cf22..00019cc7b19c5af677f60ecf969c55ef259544bd 100644
--- a/src/box/memtx_tree.h
+++ b/src/box/memtx_tree.h
@@ -68,7 +68,7 @@ class MemtxTree: public Index {
 				      struct tuple *new_tuple,
 				      enum dup_replace_mode mode);
 
-	virtual size_t memsize() const;
+	virtual size_t bsize() const;
 	virtual struct iterator *allocIterator() const;
 	virtual void initIterator(struct iterator *iterator,
 				  enum iterator_type type,
diff --git a/src/box/sophia_index.cc b/src/box/sophia_index.cc
index 5bb10b2de896b5f00a7eb39b179366742d872b27..54ed7fa21df021704f3482c3a5c9132d7bbc9b1d 100644
--- a/src/box/sophia_index.cc
+++ b/src/box/sophia_index.cc
@@ -194,7 +194,7 @@ SophiaIndex::size() const
 }
 
 size_t
-SophiaIndex::memsize() const
+SophiaIndex::bsize() const
 {
 	void *c = sp_ctl(env);
 	char name[128];
diff --git a/src/box/sophia_index.h b/src/box/sophia_index.h
index 8a9bacc0c08bc09bc958a47302e05bf003a1c5bd..cbef29754e34758de95997a621b5218e37e96b94 100644
--- a/src/box/sophia_index.h
+++ b/src/box/sophia_index.h
@@ -46,7 +46,7 @@ class SophiaIndex: public Index {
 	virtual void initIterator(struct iterator *iterator,
 				  enum iterator_type type,
 				  const char *key, uint32_t part_count) const;
-	virtual size_t memsize() const;
+	virtual size_t bsize() const;
 
 	void *env;
 	void *db;
diff --git a/src/box/space.cc b/src/box/space.cc
index 261c455041bc68b150fe167cd33c362366e4f71e..1a2054a09e38c830aca25bf2428dba74529d8b1a 100644
--- a/src/box/space.cc
+++ b/src/box/space.cc
@@ -185,7 +185,7 @@ space_stat(struct space *sp)
 		if (index) {
 			space_stat.index[i].id      = i;
 			space_stat.index[i].keys    = index->size();
-			space_stat.index[i].memsize = index->memsize();
+			space_stat.index[i].bsize   = index->bsize();
 		} else
 			space_stat.index[i].id = -1;
 	}
diff --git a/src/box/space.h b/src/box/space.h
index dd513be6259cacaaaf0d6f2b00f92a1b8be20fc4..fc326c4bd0857ccbfc7f2cb713438b767e954f87 100644
--- a/src/box/space.h
+++ b/src/box/space.h
@@ -271,7 +271,7 @@ space_run_triggers(struct space *space, bool yesno);
 struct index_stat {
 	int32_t id;
 	int64_t keys;
-	int64_t memsize;
+	int64_t bsize;
 };
 
 struct space_stat {
diff --git a/src/ffisyms.cc b/src/ffisyms.cc
index b2917b1798336b13b4b11adefc4eef69d4aa14ca..5062a2af1caa17d69b5e6223aef97c9752acdcc6 100644
--- a/src/ffisyms.cc
+++ b/src/ffisyms.cc
@@ -34,7 +34,7 @@ void *ffi_symbols[] = {
 	(void *) tuple_next,
 	(void *) tuple_unref,
 	(void *) boxffi_index_len,
-	(void *) boxffi_index_memsize,
+	(void *) boxffi_index_bsize,
 	(void *) boxffi_index_random,
 	(void *) boxffi_index_get,
 	(void *) boxffi_index_iterator,
diff --git a/test/big/hash.result b/test/big/hash.result
index d511bdc0773ae0a746072589a1f589b2c83829a5..b5a1ecc0e52c90114b27160f00f796c752a5443d 100644
--- a/test/big/hash.result
+++ b/test/big/hash.result
@@ -13,6 +13,9 @@ hash = box.schema.space.create('tweedledum')
 tmp = hash:create_index('primary', { type = 'hash', parts = {1, 'num'}, unique = true })
 ---
 ...
+bsize = tmp:bsize()
+---
+...
 -- Insert valid fields
 hash:insert{0, 'value1 v1.0', 'value2 v1.0'}
 ---
@@ -30,6 +33,10 @@ hash:insert{3, 'value1 v1.0', 'value2 v1.0'}
 ---
 - [3, 'value1 v1.0', 'value2 v1.0']
 ...
+tmp:bsize() > bsize
+---
+- true
+...
 -- Insert invalid fields
 hash:insert{'invalid key', 'value1 v1.0', 'value2 v1.0'}
 ---
diff --git a/test/big/hash.test.lua b/test/big/hash.test.lua
index 3df6f0be422b2f2cbf4404e869604b86d41a33b7..bf505b3c3fd5cd75f1485e16bf0b89e91b9e58a7 100644
--- a/test/big/hash.test.lua
+++ b/test/big/hash.test.lua
@@ -9,12 +9,16 @@ dofile('utils.lua')
 hash = box.schema.space.create('tweedledum')
 tmp = hash:create_index('primary', { type = 'hash', parts = {1, 'num'}, unique = true })
 
+bsize = tmp:bsize()
+
 -- Insert valid fields
 hash:insert{0, 'value1 v1.0', 'value2 v1.0'}
 hash:insert{1, 'value1 v1.0', 'value2 v1.0'}
 hash:insert{2, 'value1 v1.0', 'value2 v1.0'}
 hash:insert{3, 'value1 v1.0', 'value2 v1.0'}
 
+tmp:bsize() > bsize
+
 -- Insert invalid fields
 hash:insert{'invalid key', 'value1 v1.0', 'value2 v1.0'}
 
diff --git a/test/big/tree_pk.result b/test/big/tree_pk.result
index d75f06d5a05073dceee7e4759d0e868991538bef..a8a3f3cf35623cbfd5286a127fb3db10c48ee96f 100644
--- a/test/big/tree_pk.result
+++ b/test/big/tree_pk.result
@@ -7,6 +7,9 @@ s0 = box.schema.space.create('tweedledum')
 i0 = s0:create_index('primary', { type = 'tree', parts = {1, 'num'}, unique = true })
 ---
 ...
+bsize = i0:bsize()
+---
+...
 -- integer keys
 s0:insert{1, 'tuple'}
 ---
@@ -24,6 +27,10 @@ box.snapshot()
 ---
 - ok
 ...
+i0:bsize() > bsize
+---
+- true
+...
 s0:insert{3, 'tuple 3'}
 ---
 - [3, 'tuple 3']
diff --git a/test/big/tree_pk.test.lua b/test/big/tree_pk.test.lua
index fc48c6f7e71024a1e3799c604037f6b1210d46e1..6a696143ff45b3d68c8bb8eb11ac8cb9f88f7847 100644
--- a/test/big/tree_pk.test.lua
+++ b/test/big/tree_pk.test.lua
@@ -3,12 +3,16 @@ dofile('utils.lua')
 s0 = box.schema.space.create('tweedledum')
 i0 = s0:create_index('primary', { type = 'tree', parts = {1, 'num'}, unique = true })
 
+bsize = i0:bsize()
+
 -- integer keys
 s0:insert{1, 'tuple'}
 box.snapshot()
 s0:insert{2, 'tuple 2'}
 box.snapshot()
 
+i0:bsize() > bsize
+
 s0:insert{3, 'tuple 3'}
 s0.index['primary']:get{1}
 s0.index['primary']:get{2}