diff --git a/src/asami/core.cljc b/src/asami/core.cljc
index 1d08d8a..e8a39e6 100644
--- a/src/asami/core.cljc
+++ b/src/asami/core.cljc
@@ -19,6 +19,14 @@
 
 (defonce connections (atom {}))
 
+(defn shutdown
+  "Releases all connection resources for a clean shutdown"
+  []
+  (doseq [connection (vals @connections)] (storage/release connection)))
+
+#?(:clj
+   (.addShutdownHook (Runtime/getRuntime) (Thread. shutdown)))
+
 (s/defn ^:private parse-uri :- {:type s/Str
                                 :name s/Str}
   "Splits up a database URI string into structured parts"
@@ -81,9 +89,10 @@
       (storage/delete-database conn))
     ;; database not in the connections
     ;; connect to it to free its resources
-    (when (db-exists? uri)
-      (if-let [conn (connection-for uri)]
-        (storage/delete-database conn)))))
+    (boolean
+     (when (db-exists? uri)
+       (if-let [conn (connection-for uri)]
+         (storage/delete-database conn))))))
 
 (s/defn get-database-names
   "Returns a seq of database names that this instance is aware of."
diff --git a/src/asami/durable/block/block_api.cljc b/src/asami/durable/block/block_api.cljc
index 35a5363..29b474d 100644
--- a/src/asami/durable/block/block_api.cljc
+++ b/src/asami/durable/block/block_api.cljc
@@ -30,3 +30,6 @@
   (get-block [this id] "Returns the block associated with an ID.")
   (get-block-size [this] "Returns the size of blocks allocated by this manager")
   (copy-to-tx [this block] "Returns a block that is in the current transaction, possibly returning the current block"))
+
+(defprotocol CountedBlocks
+  (get-block-count [this] "Returns the number of blocks that this object has allocated, or nil if not managed by this object."))
diff --git a/src/asami/durable/block/file/block_file.clj b/src/asami/durable/block/file/block_file.clj
index 3836048..9920ee8 100644
--- a/src/asami/durable/block/file/block_file.clj
+++ b/src/asami/durable/block/file/block_file.clj
@@ -3,7 +3,7 @@
   asami.durable.block.file.block-file
   (:require [clojure.java.io :as io]
             [asami.durable.common :refer [Transaction Closeable Forceable rewind! commit! close]]
-            [asami.durable.block.block-api :refer [BlockManager copy-over! copy-block! allocate-block! get-id]]
+            [asami.durable.block.block-api :refer [CountedBlocks BlockManager copy-over! copy-block! allocate-block! get-id get-block-count]]
             [asami.durable.block.bufferblock :refer [create-block]]
             [asami.durable.block.file.voodoo :as voodoo]
             [asami.durable.cache :refer [lookup hit miss lru-cache-factory]])
@@ -45,12 +45,14 @@
 (defn open-block-file
   "Opens a file for storing blocks. Returns a structure with the block file
    and the RandomAccessFile that the block file uses. The file will need to be
-   closed when block files based on this initial block file are no longer needed."
-  [file block-size]
+   closed when block files based on this initial block file are no longer needed.
+   When the init-nr-blocks is not nil, then it holds the recorded number of blocks
+   in the file."
+  [file block-size init-nr-blocks]
   (let [file (io/file file)
         raf (RandomAccessFile. file "rw")
         ^FileChannel fc (.getChannel raf)
-        nr-blocks (long (/ (.size fc) block-size))
+        nr-blocks (or init-nr-blocks (long (/ (.size fc) block-size)))
         slack (mod region-size block-size)
         stride (if (zero? slack) region-size (+ region-size (- block-size slack)))]
     (set-nr-blocks! (->BlockFile 0 block-size 0 [] stride file raf fc) nr-blocks)))
@@ -243,12 +245,16 @@
 
   (get-block-size [this]
     (:block-size (:block-file @state)))
-  
+
   (copy-to-tx [this block]
     (if (<= (get-id block) (:commit-point @state))
       (copy-block! this block)
       block))
 
+  CountedBlocks
+  (get-block-count [this]
+    (get-nr-blocks (:block-file @state)))
+  
   Transaction
   (rewind! [this]
     (vswap! state #(assoc % :next-id (:commit-point %)))
@@ -274,9 +280,11 @@
       (.delete ^File file))))
 
 (defn create-managed-block-file
-  [filename block-size]
-  (let [block-file (open-block-file filename block-size)
+  [filename block-size nr-blocks]
+  (let [block-file (open-block-file filename block-size nr-blocks)
         next-id (dec (:nr-blocks block-file))]
+    (when (and nr-blocks (= next-id nr-blocks))
+      (throw (ex-info "Inconsistent reopening of block file" {:set-blocks nr-blocks :file-blocks (:nr-blocks block-file)})))
     (->ManagedBlockFile (volatile! {:block-file block-file
                                     :next-id next-id
                                     :commit-point next-id
diff --git a/src/asami/durable/common_utils.cljc b/src/asami/durable/common_utils.cljc
index 1e00ad9..9bef9dc 100644
--- a/src/asami/durable/common_utils.cljc
+++ b/src/asami/durable/common_utils.cljc
@@ -7,14 +7,15 @@
 
 (defn create-block-manager
   "Creates a block manager"
-  [name manager-name block-size]
+  [name manager-name block-size nr-blocks]
   #?(:clj
-     (block-file/create-managed-block-file (.getPath (io/file name manager-name)) block-size)))
+     (block-file/create-managed-block-file (.getPath (io/file name manager-name)) block-size nr-blocks)))
 
 (defn named-storage
   "A common function for opening storage with a given name. Must be provided with a storage constructor and the name.
-  The root id indicates an index root, and may be nil for an empty index."
-  [storage-constructor name root-id]
+  The root id indicates an index root, and may be nil for an empty index.
+  The block count refers to the count of blocks in the storage."
+  [storage-constructor name root-id block-count]
   #?(:clj
      (let [d (io/file name)]
        (if (.exists d)
@@ -22,4 +23,4 @@
            (throw (ex-info (str "'" name "' already exists as a file") {:path (.getAbsolutePath d)})))
          (when-not (.mkdir d)
            (throw (ex-info (str "Unable to create directory '" name "'") {:path (.getAbsolutePath d)}))))
-       (storage-constructor name root-id))))
+       (storage-constructor name root-id block-count))))
diff --git a/src/asami/durable/graph.cljc b/src/asami/durable/graph.cljc
index eaba9d4..83b128d 100644
--- a/src/asami/durable/graph.cljc
+++ b/src/asami/durable/graph.cljc
@@ -14,6 +14,7 @@
               [asami.durable.tuples :as tuples]
               [asami.durable.resolver :as resolver :refer [get-from-index get-transitive-from-index]]
               #?(:clj [asami.durable.flat-file :as flat-file])
+              [asami.durable.block.block-api :as block-api]
               [zuko.node :as node]
               [zuko.logging :as log :include-macros true]))
 
@@ -194,7 +195,10 @@
     {:r-spot (:root-id spot)
      :r-post (:root-id post)
      :r-ospt (:root-id ospt)
-     :r-pool (:root-id pool)})
+     :r-pool (:root-id pool)
+     :nr-index-node (block-api/get-block-count tree-block-manager)
+     :nr-index-block (block-api/get-block-count tuple-block-manager)
+     :nr-pool-node (block-api/get-block-count pool)})
 
   Closeable
   (close [this]
@@ -230,7 +234,7 @@
         post-index (tuples/create-tuple-index name post-name r-post)
         ospt-index (tuples/create-tuple-index name ospt-name r-ospt)
         tspo-index #?(:clj (flat-file/record-store name tspo-name tuples/tuple-size-bytes) :cljs nil)
-        data-pool (pool/create-pool name r-pool)]
+        data-pool (pool/create-pool name r-pool nil)]
     (->BlockGraph spot-index post-index ospt-index tspo-index data-pool node-allocator id-checker nil nil)))
 
 (defn new-merged-block-graph
@@ -238,15 +242,15 @@
   If the resources do not exist, then they are created.
   name: the label of the location for the graph resources.
   tx: The transaction record for this graph."
-  [name {:keys [r-spot r-post r-ospt r-pool]} node-allocator id-checker]
+  [name {:keys [r-spot r-post r-ospt r-pool nr-index-node nr-index-block nr-pool-node]} node-allocator id-checker]
   ;; NOTE: Tree nodes blocks must hold the tuples payload and the tree node header
-  (let [tree-block-manager (common-utils/create-block-manager name index-name tuples/tree-block-size)
-        tuple-block-manager (common-utils/create-block-manager name block-name tuples/block-bytes)
+  (let [tree-block-manager (common-utils/create-block-manager name index-name tuples/tree-block-size nr-index-node)
+        tuple-block-manager (common-utils/create-block-manager name block-name tuples/block-bytes nr-index-block)
         spot-index (tuples/create-tuple-index-for-managers "SPO" tree-block-manager tuple-block-manager r-spot)
         post-index (tuples/create-tuple-index-for-managers "POS" tree-block-manager tuple-block-manager r-post)
         ospt-index (tuples/create-tuple-index-for-managers "OSP" tree-block-manager tuple-block-manager r-ospt)
         tspo-index #?(:clj (flat-file/record-store name tspo-name tuples/tuple-size-bytes) :cljs nil)
-        data-pool (pool/create-pool name r-pool)]
+        data-pool (pool/create-pool name r-pool nr-pool-node)]
     (->BlockGraph spot-index post-index ospt-index tspo-index data-pool node-allocator id-checker
                   tree-block-manager tuple-block-manager)))
 
diff --git a/src/asami/durable/pool.cljc b/src/asami/durable/pool.cljc
index a55876f..868efea 100644
--- a/src/asami/durable/pool.cljc
+++ b/src/asami/durable/pool.cljc
@@ -8,7 +8,8 @@
               [asami.durable.tree :as tree]
               [asami.durable.encoder :as encoder :refer [to-bytes]]
               [asami.durable.decoder :as decoder :refer [type-info long-bytes-compare]]
-              [asami.durable.block.block-api :refer [get-long get-byte get-bytes put-byte! put-bytes! put-long! get-id]]
+              [asami.durable.block.block-api :refer [get-long get-byte get-bytes put-byte! put-bytes! put-long! get-id
+                                                     CountedBlocks get-block-count]]
               [asami.durable.cache :refer [lookup hit miss lru-cache-factory]]
               #?(:clj [asami.durable.flat-file :as flat-file])))
 
@@ -124,6 +125,11 @@
   (at [this new-root-id]
     (->ReadOnlyPool data (tree/at index new-root-id) new-root-id cache))
 
+  CountedBlocks
+  (get-block-count
+    [this]
+    (get-block-count index))
+  
   Transaction
   (commit! [this]
     (force! data)
@@ -151,17 +157,17 @@
 
 (defn open-pool
   "Opens all the resources required for a pool, and returns the pool structure"
-  [name root-id]
+  [name root-id block-count]
   (let [data-store (data-constructor name data-name)
         data-compare (pool-comparator-fn data-store)
         index (tree/new-block-tree (fn
                                      ([] true)
-                                     ([lname size] (common-utils/create-block-manager name lname size)))
+                                     ([lname size] (common-utils/create-block-manager name lname size block-count)))
                                    index-name tree-node-size data-compare root-id)
         encap-cache (atom (lru-cache-factory {} :threshold encap-cache-size))]
    (->DataPool data-store index root-id encap-cache)))
 
 (defn create-pool
   "Creates a datapool object"
-  ([name] (create-pool name nil))
-  ([name root-id] (common-utils/named-storage open-pool name root-id)))
+  ([name] (create-pool name nil nil))
+  ([name root-id block-count] (common-utils/named-storage open-pool name root-id block-count)))
diff --git a/src/asami/durable/store.cljc b/src/asami/durable/store.cljc
index 907d2a5..3510c31 100644
--- a/src/asami/durable/store.cljc
+++ b/src/asami/durable/store.cljc
@@ -25,13 +25,17 @@
 
 ;; transactions contain tree roots for the 3 tree indices,
 ;; the tree root for the data pool,
+;; the 3 block counts for the tuples index tree, the tuples blocks, and the data pool index tree
 ;; the internal node counter
-(def tx-record-size (* 5 common/long-size))
+(def tx-record-size (* 8 common/long-size))
 
 (def TxRecord {(s/required-key :r-spot) (s/maybe s/Int)
                (s/required-key :r-post) (s/maybe s/Int)
                (s/required-key :r-ospt) (s/maybe s/Int)
                (s/required-key :r-pool) (s/maybe s/Int)
+               (s/required-key :nr-index-node) (s/maybe s/Int)
+               (s/required-key :nr-index-block) (s/maybe s/Int)
+               (s/required-key :nr-pool-node) (s/maybe s/Int)
                (s/required-key :nodes) s/Int
                (s/required-key :timestamp) s/Int})
 
@@ -40,27 +44,37 @@
                                                 (s/one s/Int "post root id")
                                                 (s/one s/Int "ospt root id")
                                                 (s/one s/Int "pool root id")
+                                                (s/one s/Int "number of index nodes allocated")
+                                                (s/one s/Int "number of index blocks allocated")
+                                                (s/one s/Int "number of pool index nodes allocated")
                                                 (s/one s/Int "node id counter")]})
 
 (s/defn pack-tx :- TxRecordPacked
   "Packs a transaction into a vector for serialization"
-  [{:keys [r-spot r-post r-ospt r-pool nodes timestamp]} :- TxRecord]
-  {:timestamp timestamp :tx-data [(or r-spot 0) (or r-post 0) (or r-ospt 0) (or r-pool 0) nodes]})
+  [{:keys [r-spot r-post r-ospt r-pool nr-index-node nr-index-block nr-pool-node nodes timestamp]} :- TxRecord]
+  {:timestamp timestamp :tx-data [(or r-spot 0) (or r-post 0) (or r-ospt 0) (or r-pool 0)
+                                  (or nr-index-node 0) (or nr-index-block 0) (or nr-pool-node 0)
+                                  nodes]})
 
 (s/defn unpack-tx :- TxRecord
   "Unpacks a transaction vector into a structure when deserializing"
-  [{[r-spot r-post r-ospt r-pool nodes] :tx-data timestamp :timestamp} :- TxRecordPacked]
+  [{[r-spot r-post r-ospt r-pool
+     nr-index-node nr-index-block nr-pool-node nodes] :tx-data
+    timestamp :timestamp} :- TxRecordPacked]
   (letfn [(non-zero [v] (and v (when-not (zero? v) v)))]
     {:r-spot (non-zero r-spot)
      :r-post (non-zero r-post)
      :r-ospt (non-zero r-ospt)
      :r-pool (non-zero r-pool)
+     :nr-index-node (non-zero nr-index-node)
+     :nr-index-block (non-zero nr-index-block)
+     :nr-pool-node (non-zero nr-pool-node)
      :nodes nodes
      :timestamp timestamp}))
 
 (s/defn new-db :- TxRecordPacked
   []
-  {:timestamp (long-time (now)) :tx-data [0 0 0 0 0]})
+  {:timestamp (long-time (now)) :tx-data [0 0 0 0 0 0 0 0]})
 
 (declare ->DurableDatabase)
 
diff --git a/src/asami/durable/tree.cljc b/src/asami/durable/tree.cljc
index 37d2ef7..bbd9c9c 100644
--- a/src/asami/durable/tree.cljc
+++ b/src/asami/durable/tree.cljc
@@ -1,14 +1,14 @@
 (ns ^{:doc "This namespace provides the basic mechanisms for AVL trees"
       :author "Paula Gearon"}
     asami.durable.tree
-  (:require [asami.durable.block.block-api :refer [Block
+  (:require [asami.durable.block.block-api :refer [Block CountedBlocks
                                                    get-id get-byte get-int get-long
                                                    get-bytes get-ints get-longs
                                                    put-byte! put-int! put-long!
                                                    put-bytes! put-ints! put-longs!
                                                    put-block! copy-over!
                                                    allocate-block! get-block get-block-size
-                                                   write-block copy-to-tx]]
+                                                   write-block copy-to-tx get-block-count]]
             [asami.durable.common :refer [Transaction Closeable Forceable close delete! rewind! commit! force! long-size]]
             [asami.durable.cache :refer [lookup hit miss lru-cache-factory]]))
 
@@ -29,6 +29,11 @@
 
 (def ^:const node-cache-size 1024)
 
+(defn to-hex
+  [n]
+  #?(:clj (Long/toHexString n)
+     :cljs (.toString n 16)))
+
 (defprotocol TreeNode
   (get-parent [this] "Returns the parent node. Not the Node ID, but the node object.")
   (get-child-id [this side] "Gets the Node ID of the child on the given side")
@@ -96,7 +101,7 @@
 
   Object
   (toString [this]
-    (let [payload (mapv #(Long/toHexString (get-long this %)) (range (/ (- (:size block) header-size) 8)))]
+    (let [payload (mapv #(to-hex (get-long this %)) (range (/ (- (:size block) header-size) 8)))]
       (str "Node[" (get-id this) "] L:" (get-child-id this left) " R:" (get-child-id this right) " payload:"
            payload)))
 
@@ -389,6 +394,11 @@
               ;; if modified-node is not yet set, then new-node was the root
               [(assoc this :root nd) (or modified-node new-node)]))))))
 
+  CountedBlocks
+  (get-block-count [this]
+    (when own-manager
+      (get-block-count block-manager)))
+
   Transaction
   (rewind! [this]
     (when own-manager
diff --git a/src/asami/durable/tuples.cljc b/src/asami/durable/tuples.cljc
index b685dd6..5c67719 100644
--- a/src/asami/durable/tuples.cljc
+++ b/src/asami/durable/tuples.cljc
@@ -591,9 +591,9 @@
 (defn open-tuples
   [order-name name root-id]
   ;; create a factory fn that returns true on 0-arity to indicate that the index manager is owned by the calling tree
-  (let [index (tree/new-block-tree (fn ([] true) ([lname size] (common-utils/create-block-manager name lname size)))
+  (let [index (tree/new-block-tree (fn ([] true) ([lname size] (common-utils/create-block-manager name lname size nil)))
                                    (str order-name index-name) tree-node-size tuple-node-compare root-id)
-        blocks (common-utils/create-block-manager name (str order-name block-name) block-bytes)]
+        blocks (common-utils/create-block-manager name (str order-name block-name) block-bytes nil)]
     (->TupleIndex name index blocks root-id true)))
 
 (defn create-tuple-index
@@ -601,4 +601,4 @@
   ([name order-name]
    (create-tuple-index name order-name nil))
   ([name order-name root-id]
-   (common-utils/named-storage (partial open-tuples order-name) name root-id)))
+   (common-utils/named-storage (partial open-tuples order-name) name root-id nil)))
diff --git a/test/asami/durable/block/blockfile_test.clj b/test/asami/durable/block/blockfile_test.clj
index 54d21b5..4a1cebd 100644
--- a/test/asami/durable/block/blockfile_test.clj
+++ b/test/asami/durable/block/blockfile_test.clj
@@ -19,7 +19,7 @@
 (defn exec-bf
   [filename f]
   (let [filename (util/temp-file filename)
-        {:keys [block-file file]} (open-block-file filename test-block-size)]
+        {:keys [block-file file]} (open-block-file filename test-block-size nil)]
     (try
       (f file block-file)
       (finally
@@ -34,7 +34,7 @@
 
 (deftest test-allocate
   (let [filename (util/temp-file "ualloc")
-        block-file (open-block-file filename test-block-size)
+        block-file (open-block-file filename test-block-size nil)
         block-file (set-nr-blocks! block-file 1)]
     (try
       (let [blk (block-for block-file 0)]
@@ -48,7 +48,7 @@
 (deftest test-write
   (let [file-str "bftest"
         filename (util/temp-file file-str)
-        block-file (open-block-file filename test-block-size)
+        block-file (open-block-file filename test-block-size nil)
         bf (set-nr-blocks! block-file 4)
         b (block-for bf 0)
         _ (put-string! b str0)
@@ -68,7 +68,7 @@
     (unmap bf)
     (cleanup)
 
-    (let [block-file (open-block-file filename test-block-size)]
+    (let [block-file (open-block-file filename test-block-size nil)]
       
       ;; did it persist
       
@@ -87,7 +87,7 @@
 (deftest test-performance
   (let [file-str "perftest"
         filename (util/temp-file file-str)
-        block-file (open-block-file filename test-block-size)
+        block-file (open-block-file filename test-block-size nil)
         block-file (clear! block-file)
         nr-blocks 100000
         bf (set-nr-blocks! block-file nr-blocks)]
diff --git a/test/asami/durable/block/blockmanager_test.cljc b/test/asami/durable/block/blockmanager_test.cljc
index caf8c64..92f3cb5 100644
--- a/test/asami/durable/block/blockmanager_test.cljc
+++ b/test/asami/durable/block/blockmanager_test.cljc
@@ -27,13 +27,13 @@
   [s sz]
   (let [f (get-filename s)]
     [f
-     #?(:clj (create-managed-block-file f sz))]))
+     #?(:clj (create-managed-block-file f sz nil))]))
 
 (defn recreate-block-manager
   "Central BlockManager construction. On the JVM this is ManagedBlockFile.
   Takes an argument for creating the manager (e.g. File, or string), and a size."
   [f sz]
-  #?(:clj (create-managed-block-file f sz)))
+  #?(:clj (create-managed-block-file f sz nil)))
 
 (defn remove-file
   "Remove block manager resources."
diff --git a/test/asami/durable/block_tree_test.cljc b/test/asami/durable/block_tree_test.cljc
index c001fa1..6969fc9 100644
--- a/test/asami/durable/block_tree_test.cljc
+++ b/test/asami/durable/block_tree_test.cljc
@@ -23,7 +23,7 @@
       (let [f (if reuse?
                 (util/temp-file name)
                 (get-filename name))]
-        (create-managed-block-file f block-size))
+        (create-managed-block-file f block-size nil))
 
       :cljs
       ;; TODO: create ClojureScript block manager
diff --git a/test/asami/durable/pool_test.cljc b/test/asami/durable/pool_test.cljc
index 6a66e4c..2e6e120 100644
--- a/test/asami/durable/pool_test.cljc
+++ b/test/asami/durable/pool_test.cljc
@@ -96,7 +96,7 @@
       (is (= id (find-id pool value)) (str "data: " value)))
     (close pool)
 
-    (let [pool2 (create-pool "pool-test" root)]
+    (let [pool2 (create-pool "pool-test" root nil)]
       (doseq [[id value] (map vector ids data)]
         (is (= value (find-object pool2 id))))
 
@@ -194,7 +194,7 @@
 
     (close bpool)
 
-    (let [new-pool (create-pool "book2" root)
+    (let [new-pool (create-pool "book2" root nil)
           g2 (find-id new-pool "Gutenberg")
           output-words2 (map #(find-object new-pool %) coded)
           [coded2 bpool2] (load-strings! words new-pool)]