kvstore fixes (#350)

Storing large blobs in a "WITHOUT ROWID" table turns out to be extremely
slow when the tree must be rebalanced.

* Split out keystore capability into separate interface, making each
keystore a separate instance
* Disable "WITHOUT ROWID" optimization by default
* Implement prefix lookup that allows iterating over all values with a
certain prefix in their key

eth/db/kvstore.nim

@@ -26,9 +26,11 @@ type
   KvResult*[T] = Result[T, string]
 
   DataProc* = proc(val: openArray[byte]) {.gcsafe, raises: [Defect].}
+  KeyValueProc* = proc(key, val: openArray[byte]) {.gcsafe, raises: [Defect].}
 
   PutProc = proc (db: RootRef, key, val: openArray[byte]): KvResult[void] {.nimcall, gcsafe, raises: [Defect].}
   GetProc = proc (db: RootRef, key: openArray[byte], onData: DataProc): KvResult[bool] {.nimcall, gcsafe, raises: [Defect].}
+  FindProc = proc (db: RootRef, prefix: openArray[byte], onFind: KeyValueProc): KvResult[int] {.nimcall, gcsafe, raises: [Defect].}
   DelProc = proc (db: RootRef, key: openArray[byte]): KvResult[void] {.nimcall, gcsafe, raises: [Defect].}
   ContainsProc = proc (db: RootRef, key: openArray[byte]): KvResult[bool] {.nimcall, gcsafe, raises: [Defect].}
   CloseProc = proc (db: RootRef): KvResult[void] {.nimcall, gcsafe, raises: [Defect].}
@@ -38,6 +40,7 @@ type
     obj: RootRef
     putProc: PutProc
     getProc: GetProc
+    findProc: FindProc
     delProc: DelProc
     containsProc: ContainsProc
     closeProc: CloseProc
@@ -55,6 +58,16 @@ template get*(dbParam: KvStoreRef, key: openArray[byte], onData: untyped): KvRes
   let db = dbParam
   db.getProc(db.obj, key, onData)
 
+template find*(
+    dbParam: KvStoreRef, prefix: openArray[byte], onFind: untyped): KvResult[int] =
+  ## Perform a prefix find, returning all data starting with the given prefix.
+  ## An empty prefix returns all rows in the store.
+  ## The data is valid for the duration of the callback.
+  ## ``onFind``: ``proc(key, value: openArray[byte])``
+  ## returns the number of rows found
+  let db = dbParam
+  db.findProc(db.obj, prefix, onFind)
+
 template del*(dbParam: KvStoreRef, key: openArray[byte]): KvResult[void] =
   ## Remove value at ``key`` from store - do nothing if the value is not present
   let db = dbParam
@@ -78,6 +91,10 @@ proc getImpl[T](db: RootRef, key: openArray[byte], onData: DataProc): KvResult[b
   mixin get
   get(T(db), key, onData)
 
+proc findImpl[T](db: RootRef, key: openArray[byte], onFind: KeyValueProc): KvResult[int] =
+  mixin get
+  find(T(db), key, onFind)
+
 proc delImpl[T](db: RootRef, key: openArray[byte]): KvResult[void] =
   mixin del
   del(T(db), key)
@@ -97,6 +114,7 @@ func kvStore*[T: RootRef](x: T): KvStoreRef =
     obj: x,
     putProc: putImpl[T],
     getProc: getImpl[T],
+    findProc: findImpl[T],
     delProc: delImpl[T],
     containsProc: containsImpl[T],
     closeProc: closeImpl[T]
@@ -109,6 +127,18 @@ proc get*(db: MemStoreRef, key: openArray[byte], onData: DataProc): KvResult[boo
 
   ok(false)
 
+proc find*(
+    db: MemStoreRef, prefix: openArray[byte],
+    onFind: KeyValueProc): KvResult[int] =
+  var total = 0
+  # Should use lower/upper bounds instead
+  for k, v in db.records:
+    if k.len() >= prefix.len and k.toOpenArray(0, prefix.len() - 1) == prefix:
+      onFind(k, v)
+      total += 1
+
+  ok(total)
+
 proc del*(db: MemStoreRef, key: openArray[byte]): KvResult[void] =
   db.records.del(@key)
   ok()

eth/db/kvstore_rocksdb.nim

@@ -16,6 +16,9 @@ type
 proc get*(db: RocksStoreRef, key: openarray[byte], onData: kvstore.DataProc): KvResult[bool] =
   db.store.get(key, onData)
 
+proc find*(db: RocksStoreRef, prefix: openarray[byte], onFind: kvstore.KeyValueProc): KvResult[int] =
+  raiseAssert "Unimplemented"
+
 proc put*(db: RocksStoreRef, key, value: openarray[byte]): KvResult[void] =
   db.store.put(key, value)
 

eth/db/kvstore_sqlite3.nim

@@ -3,7 +3,7 @@
 {.push raises: [Defect].}
 
 import
-  std/[os, strformat],
+  std/[os, options, strformat],
   sqlite3_abi,
   ./kvstore
 
@@ -24,17 +24,23 @@ type
   NoParams* = tuple # this is the empty tuple
   ResultHandler*[T] = proc(val: T) {.gcsafe, raises: [Defect].}
 
-  KeySpaceStatements = object
+  SqStoreRef* = ref object
-    getStmt, putStmt, delStmt, containsStmt: RawStmtPtr
+    # Handle for a single database - from here, keyspaces and statements
-
+    # can be created
-  SqStoreRef* = ref object of RootObj
     env: Sqlite
-    keyspaces: seq[KeySpaceStatements]
     managedStmts: seq[RawStmtPtr]
 
   SqStoreCheckpointKind* {.pure.} = enum
     passive, full, restart, truncate
 
+  SqKeyspace* = object of RootObj
+    # A Keyspace is a single key-value table - it is generally efficient to
+    # create separate keyspaces for each type of data stored
+    getStmt, putStmt, delStmt, containsStmt,
+      findStmt0, findStmt1, findStmt2: RawStmtPtr
+
+  SqKeyspaceRef* = ref SqKeyspace
+
 template dispose(db: Sqlite) =
   discard sqlite3_close(db)
 
@@ -72,7 +78,7 @@ proc prepareStmt*(db: SqStoreRef,
   ok SqliteStmt[Params, Res](s)
 
 proc bindParam(s: RawStmtPtr, n: int, val: auto): cint =
-  when val is openarray[byte]|seq[byte]:
+  when val is openArray[byte]|seq[byte]:
     if val.len > 0:
       sqlite3_bind_blob(s, n.cint, unsafeAddr val[0], val.len.cint, nil)
     else:
@@ -80,7 +86,7 @@ proc bindParam(s: RawStmtPtr, n: int, val: auto): cint =
   elif val is array:
     when val.items.typeof is byte:
       # Prior to Nim 1.4 and view types array[N, byte] in tuples
-      # don't match with openarray[byte]
+      # don't match with openArray[byte]
       if val.len > 0:
         sqlite3_bind_blob(s, n.cint, unsafeAddr val[0], val.len.cint, nil)
       else:
@@ -126,7 +132,7 @@ template readResult(s: RawStmtPtr, column: cint, T: type): auto =
     sqlite3_column_int64(s, column)
   elif T is int:
     {.fatal: "Please use specify either int32 or int64 precisely".}
-  elif T is openarray[byte]:
+  elif T is openArray[byte]:
     let
       p = cast[ptr UncheckedArray[byte]](sqlite3_column_blob(s, column))
       l = sqlite3_column_bytes(s, column)
@@ -209,11 +215,11 @@ proc exec*[Params: tuple](db: SqStoreRef,
 template exec*(db: SqStoreRef, stmt: string): KvResult[void] =
   exec(db, stmt, ())
 
-proc getImpl(db: SqStoreRef,
+proc get*(db: SqKeyspaceRef,
-             keyspace: int,
+          key: openArray[byte],
-             key: openarray[byte],
+          onData: DataProc): KvResult[bool] =
-             onData: DataProc): KvResult[bool] =
+  if db.getStmt == nil: return err("sqlite: database closed")
-  let getStmt = db.keyspaces[keyspace].getStmt
+  let getStmt = db.getStmt
   checkErr bindParam(getStmt, 1, key)
 
   let
@@ -236,15 +242,77 @@ proc getImpl(db: SqStoreRef,
 
   res
 
-proc get*(db: SqStoreRef, key: openarray[byte], onData: DataProc): KvResult[bool] =
+func nextPrefix(prefix: openArray[byte], next: var seq[byte]): bool =
-  getImpl(db, 0, key, onData)
+  # Return a seq that is greater than all strings starting with `prefix` when
+  # doing a lexicographical compare - we're looking for the string that
+  # increments the last byte by 1, removing any bytes from the back that
+  # cannot be incremented (0xff)
 
-template get*(db: SqStoreRef, keyspace: int, key: openarray[byte], onData: DataProc): KvResult[bool] =
+  for i in 0..<prefix.len():
-  getImpl(db, keyspace, key, onData)
+    if prefix[^(i+1)] == high(byte):
+      if i == 0:
+        return false
+      else:
+        next = prefix[0..<i]
+        next[^1] += 1'u8
+        return true
 
-proc putImpl(db: SqStoreRef, keyspace: int, key, value: openarray[byte]): KvResult[void] =
+  false # Empty
-  let putStmt = db.keyspaces[keyspace].putStmt
 
+proc find*(
+    db: SqKeyspaceRef,
+    prefix: openArray[byte],
+    onFind: KeyValueProc): KvResult[int] =
+  var next: seq[byte] # extended lifetime of bound param
+  let findStmt =
+    if prefix.len == 0:
+      db.findStmt0 # all rows
+    else:
+      if not nextPrefix(prefix, next):
+        # For example when looking for the prefix [byte 255], there are no
+        # prefixes that lexicographically are greater, thus we use the
+        # query that only does the >= comparison
+        checkErr bindParam(db.findStmt1, 1, prefix)
+        db.findStmt1
+      else:
+        checkErr bindParam(db.findStmt2, 1, prefix)
+        checkErr bindParam(db.findStmt2, 2, next)
+        db.findStmt2
+
+  if findStmt == nil: return err("sqlite: database closed")
+
+  var
+    total = 0
+  while true:
+    let
+      v = sqlite3_step(findStmt)
+    case v
+    of SQLITE_ROW:
+      let
+        kp = cast[ptr UncheckedArray[byte]](sqlite3_column_blob(findStmt, 0))
+        kl = sqlite3_column_bytes(findStmt, 0)
+        vp = cast[ptr UncheckedArray[byte]](sqlite3_column_blob(findStmt, 1))
+        vl = sqlite3_column_bytes(findStmt, 1)
+      onFind(kp.toOpenArray(0, kl - 1), vp.toOpenArray(0, vl - 1))
+      total += 1
+    of SQLITE_DONE:
+      break
+    else:
+      # release implicit transaction (could use a defer, but it's slow)
+      discard sqlite3_reset(findStmt) # same return information as step
+      discard sqlite3_clear_bindings(findStmt) # no errors possible
+
+      return err($sqlite3_errstr(v))
+
+  # release implicit transaction
+  discard sqlite3_reset(findStmt) # same return information as step
+  discard sqlite3_clear_bindings(findStmt) # no errors possible
+
+  ok(total)
+
+proc put*(db: SqKeyspaceRef, key, value: openArray[byte]): KvResult[void] =
+  let putStmt = db.putStmt
+  if putStmt == nil: return err("sqlite: database closed")
   checkErr bindParam(putStmt, 1, key)
   checkErr bindParam(putStmt, 2, value)
 
@@ -260,14 +328,9 @@ proc putImpl(db: SqStoreRef, keyspace: int, key, value: openarray[byte]): KvResu
 
   res
 
-proc put*(db: SqStoreRef, key, value: openarray[byte]): KvResult[void] =
+proc contains*(db: SqKeyspaceRef, key: openArray[byte]): KvResult[bool] =
-  putImpl(db, 0, key, value)
+  let containsStmt = db.containsStmt
-
+  if containsStmt == nil: return err("sqlite: database closed")
-template put*(db: SqStoreRef, keyspace: int, key, value: openarray[byte]): KvResult[void] =
-  putImpl(db, keyspace, key, value)
-
-proc containsImpl(db: SqStoreRef, keyspace: int, key: openarray[byte]): KvResult[bool] =
-  let containsStmt = db.keyspaces[keyspace].containsStmt
   checkErr bindParam(containsStmt, 1, key)
 
   let
@@ -283,14 +346,9 @@ proc containsImpl(db: SqStoreRef, keyspace: int, key: openarray[byte]): KvResult
 
   res
 
-proc contains*(db: SqStoreRef, key: openarray[byte]): KvResult[bool] =
+proc del*(db: SqKeyspaceRef, key: openArray[byte]): KvResult[void] =
-  containsImpl(db, 0, key)
+  let delStmt = db.delStmt
-
+  if delStmt == nil: return err("sqlite: database closed")
-template contains*(db: SqStoreRef, keyspace: int, key: openarray[byte]): KvResult[bool] =
-  containsImpl(db, keyspace, key)
-
-proc delImpl(db: SqStoreRef, keyspace: int, key: openarray[byte]): KvResult[void] =
-  let delStmt = db.keyspaces[keyspace].delStmt
   checkErr bindParam(delStmt, 1, key)
 
   let res =
@@ -305,23 +363,26 @@ proc delImpl(db: SqStoreRef, keyspace: int, key: openarray[byte]): KvResult[void
 
   res
 
-proc del*(db: SqStoreRef, key: openarray[byte]): KvResult[void] =
+proc close*(db: var SqKeyspace) =
-  delImpl(db, 0, key)
+  # Calling with null stmt is harmless
+  discard sqlite3_finalize(db.putStmt)
+  discard sqlite3_finalize(db.getStmt)
+  discard sqlite3_finalize(db.delStmt)
+  discard sqlite3_finalize(db.containsStmt)
+  discard sqlite3_finalize(db.findStmt0)
+  discard sqlite3_finalize(db.findStmt1)
+  discard sqlite3_finalize(db.findStmt2)
+  db = SqKeyspace()
 
-template del*(db: SqStoreRef, keyspace: int, key: openarray[byte]): KvResult[void] =
+proc close*(db: SqKeyspaceRef) =
-  delImpl(db, keyspace, key)
+  close(db[])
 
 proc close*(db: SqStoreRef) =
-  for keyspace in db.keyspaces:
-    discard sqlite3_finalize(keyspace.putStmt)
-    discard sqlite3_finalize(keyspace.getStmt)
-    discard sqlite3_finalize(keyspace.delStmt)
-    discard sqlite3_finalize(keyspace.containsStmt)
-
   for stmt in db.managedStmts:
     discard sqlite3_finalize(stmt)
 
-  discard sqlite3_close(db.env)
+  # Lazy-v2-close allows closing the keyspaces in any order
+  discard sqlite3_close_v2(db.env)
 
   db[] = SqStoreRef()[]
 
@@ -333,6 +394,32 @@ proc checkpoint*(db: SqStoreRef, kind = SqStoreCheckpointKind.passive) =
   of SqStoreCheckpointKind.truncate: SQLITE_CHECKPOINT_TRUNCATE
   discard sqlite3_wal_checkpoint_v2(db.env, nil, mode, nil, nil)
 
+template prepare(env: ptr sqlite3, q: string): ptr sqlite3_stmt =
+  block:
+    var s: ptr sqlite3_stmt
+    checkErr sqlite3_prepare_v2(env, q, q.len.cint, addr s, nil):
+      discard
+    s
+
+template prepare(env: ptr sqlite3, q: string, cleanup: untyped): ptr sqlite3_stmt =
+  block:
+    var s: ptr sqlite3_stmt
+    checkErr sqlite3_prepare_v2(env, q, q.len.cint, addr s, nil)
+    s
+
+template checkExec(s: ptr sqlite3_stmt) =
+  if (let x = sqlite3_step(s); x != SQLITE_DONE):
+    discard sqlite3_finalize(s)
+    return err($sqlite3_errstr(x))
+
+  if (let x = sqlite3_finalize(s); x != SQLITE_OK):
+    return err($sqlite3_errstr(x))
+
+template checkExec(env: ptr sqlite3, q: string) =
+  block:
+    let s = prepare(env, q): discard
+    checkExec(s)
+
 proc isClosed*(db: SqStoreRef): bool =
   db.env != nil
 
@@ -342,8 +429,7 @@ proc init*(
     name: string,
     readOnly = false,
     inMemory = false,
-    manualCheckpoint = false,
+    manualCheckpoint = false): KvResult[T] =
-    keyspaces: openarray[string] = ["kvstore"]): KvResult[T] =
   var env: AutoDisposed[ptr sqlite3]
   defer: disposeIfUnreleased(env)
 
@@ -359,28 +445,10 @@ proc init*(
     try:
       createDir(basePath)
     except OSError, IOError:
-      return err("`sqlite: cannot create database directory")
+      return err("sqlite: cannot create database directory")
 
   checkErr sqlite3_open_v2(name, addr env.val, flags.cint, nil)
 
-  template prepare(q: string, cleanup: untyped): ptr sqlite3_stmt =
-    var s: ptr sqlite3_stmt
-    checkErr sqlite3_prepare_v2(env.val, q, q.len.cint, addr s, nil):
-      cleanup
-    s
-
-  template checkExec(s: ptr sqlite3_stmt) =
-    if (let x = sqlite3_step(s); x != SQLITE_DONE):
-      discard sqlite3_finalize(s)
-      return err($sqlite3_errstr(x))
-
-    if (let x = sqlite3_finalize(s); x != SQLITE_OK):
-      return err($sqlite3_errstr(x))
-
-  template checkExec(q: string) =
-    let s = prepare(q): discard
-    checkExec(s)
-
   template checkWalPragmaResult(journalModePragma: ptr sqlite3_stmt) =
     if (let x = sqlite3_step(journalModePragma); x != SQLITE_ROW):
       discard sqlite3_finalize(journalModePragma)
@@ -396,12 +464,11 @@ proc init*(
       return err("Invalid pragma result: " & $x)
 
   # TODO: check current version and implement schema versioning
-  checkExec "PRAGMA user_version = 2;"
+  checkExec env.val, "PRAGMA user_version = 3;"
 
-  let journalModePragma = prepare("PRAGMA journal_mode = WAL;"): discard
+  let journalModePragma = prepare(env.val, "PRAGMA journal_mode = WAL;")
   checkWalPragmaResult(journalModePragma)
-  checkExec(journalModePragma)
+  checkExec journalModePragma
-
 
   if manualCheckpoint:
     checkErr sqlite3_wal_autocheckpoint(env.val, 0)
@@ -409,55 +476,49 @@ proc init*(
     # this is safe in WAL mode leaving us with a consistent database at all
     # times, though potentially losing any data written between checkpoints.
     # http://www3.sqlite.org/wal.html#performance_considerations
-    checkExec("PRAGMA synchronous = NORMAL;")
+    checkExec env.val, "PRAGMA synchronous = NORMAL;"
-
-  var keyspaceStatements = newSeq[KeySpaceStatements]()
-  for keyspace in keyspaces:
-    checkExec """
-      CREATE TABLE IF NOT EXISTS """ & keyspace & """ (
-         key BLOB PRIMARY KEY,
-         value BLOB
-      );
-    """
-
-    let
-      getStmt = prepare("SELECT value FROM " & keyspace & " WHERE key = ?;"):
-        discard
-      putStmt = prepare("INSERT OR REPLACE INTO " & keyspace & "(key, value) VALUES (?, ?);"):
-        discard sqlite3_finalize(getStmt)
-      delStmt = prepare("DELETE FROM " & keyspace & " WHERE key = ?;"):
-        discard sqlite3_finalize(getStmt)
-        discard sqlite3_finalize(putStmt)
-      containsStmt = prepare("SELECT 1 FROM " & keyspace & " WHERE key = ?;"):
-        discard sqlite3_finalize(getStmt)
-        discard sqlite3_finalize(putStmt)
-        discard sqlite3_finalize(delStmt)
-
-    keyspaceStatements.add KeySpaceStatements(
-      getStmt: getStmt,
-      putStmt: putStmt,
-      delStmt: delStmt,
-      containsStmt: containsStmt)
 
   ok(SqStoreRef(
     env: env.release,
-    keyspaces: keyspaceStatements
   ))
 
-proc init*(
+proc openKvStore*(db: SqStoreRef, name = "kvstore", withoutRowid = false): KvResult[SqKeyspaceRef] =
-    T: type SqStoreRef,
+  ## Open a new Key-Value store in the SQLite database
-    basePath: string,
+  ##
-    name: string,
+  ## withoutRowid: Create the table without rowid - this is more efficient when
-    Keyspaces: type[enum],
+  ##               rows are small (<200 bytes) but very inefficient with larger
-    readOnly = false,
+  ##               rows (the row being the sum of key and value) - see
-    inMemory = false,
+  ##               https://www.sqlite.org/withoutrowid.html
-    manualCheckpoint = false): KvResult[T] =
+  ##
+  let
+    createSql = """
+      CREATE TABLE IF NOT EXISTS """ & name & """ (
+         key BLOB PRIMARY KEY,
+         value BLOB
+      )"""
 
-  var keyspaceNames = newSeq[string]()
+  checkExec db.env,
-  for keyspace in Keyspaces:
+    if withoutRowid: createSql & " WITHOUT ROWID;" else: createSql & ";"
-    keyspaceNames.add $keyspace
 
-  SqStoreRef.init(basePath, name, readOnly, inMemory, manualCheckpoint, keyspaceNames)
+  var
+    tmp: SqKeyspace
+  defer:
+    # We'll "move" ownership to the return value, effectively disabling "close"
+    close(tmp)
+
+  tmp.getStmt = prepare(db.env, "SELECT value FROM " & name & " WHERE key = ?;")
+  tmp.putStmt =
+    prepare(db.env, "INSERT OR REPLACE INTO " & name & "(key, value) VALUES (?, ?);")
+  tmp.delStmt = prepare(db.env, "DELETE FROM " & name & " WHERE key = ?;")
+  tmp.containsStmt = prepare(db.env, "SELECT 1 FROM " & name & " WHERE key = ?;")
+  tmp.findStmt0 = prepare(db.env, "SELECT key, value FROM " & name & ";")
+  tmp.findStmt1 = prepare(db.env, "SELECT key, value FROM " & name & " WHERE key >= ?;")
+  tmp.findStmt2 = prepare(db.env, "SELECT key, value FROM " & name & " WHERE key >= ? and key < ?;")
+
+  var res = SqKeyspaceRef()
+  res[] = tmp
+  tmp = SqKeyspace() # make close harmless
+  ok res
 
 when defined(metrics):
   import tables, times,

tests/db/test_kvstore.nim

@@ -8,8 +8,9 @@ const
   key = [0'u8, 1, 2, 3]
   value = [3'u8, 2, 1, 0]
   value2 = [5'u8, 2, 1, 0]
+  key2 = [255'u8, 255]
 
-proc testKvStore*(db: KvStoreRef) =
+proc testKvStore*(db: KvStoreRef, supportsFind: bool) =
   check:
     db != nil
 
@@ -20,9 +21,12 @@ proc testKvStore*(db: KvStoreRef) =
 
   db.put(key, value)[]
 
-  var v: seq[byte]
+  var k, v: seq[byte]
   proc grab(data: openArray[byte]) =
     v = @data
+  proc grab2(key, value: openArray[byte]) =
+    k = @key
+    v = @value
 
   check:
     db.contains(key)[]
@@ -42,6 +46,27 @@ proc testKvStore*(db: KvStoreRef) =
 
   db.del(key)[] # does nothing
 
+  if supportsFind:
+    check:
+      db.find([], proc(key, value: openArray[byte]) = discard).get() == 0
+
+    db.put(key, value)[]
+
+    check:
+      db.find([], grab2).get() == 1
+      db.find(key, grab2).get() == 1
+      k == key
+      v == value
+
+    db.put(key2, value2)[]
+    check:
+      db.find([], grab2).get() == 2
+      db.find([byte 255], grab2).get() == 1
+      db.find([byte 255, 255], grab2).get() == 1
+      db.find([byte 255, 255, 0], grab2).get() == 0
+      db.find([byte 255, 255, 255], grab2).get() == 0
+      db.find([byte 255, 0], grab2).get() == 0
+
 suite "MemoryStoreRef":
   test "KvStore interface":
-    testKvStore(kvStore MemStoreRef.init())
+    testKvStore(kvStore MemStoreRef.init(), true)

tests/db/test_kvstore_rocksdb.nim

@@ -14,4 +14,4 @@ suite "RocksStoreRef":
     let db = RocksStoreRef.init(tmp, "test")[]
     defer: db.close()
 
-    testKvStore(kvStore db)
+    testKvStore(kvStore db, false)

tests/db/test_kvstore_sqlite3.nim

@@ -10,8 +10,10 @@ procSuite "SqStoreRef":
   test "KvStore interface":
     let db = SqStoreRef.init("", "test", inMemory = true)[]
     defer: db.close()
+    let kv = db.openKvStore()
+    defer: kv.get()[].close()
 
-    testKvStore(kvStore db)
+    testKvStore(kvStore kv.get(), true)
 
   test "Prepare and execute statements":
     let db = SqStoreRef.init("", "test", inMemory = true)[]