diff --git a/util/src/journaldb/archivedb.rs b/util/src/journaldb/archivedb.rs
index c7f6b92fa..8372f99de 100644
--- a/util/src/journaldb/archivedb.rs
+++ b/util/src/journaldb/archivedb.rs
@@ -43,13 +43,8 @@ const DB_VERSION : u32 = 0x103;
 
 impl ArchiveDB {
 	/// Create a new instance from file
-	pub fn new(path: &str, cache_size: Option<usize>) -> ArchiveDB {
-		let opts = DatabaseConfig {
-			// this must match account_db prefix
-			prefix_size: Some(DB_PREFIX_LEN),
-			max_open_files: 256,
-			cache_size: cache_size,
-		};
+	pub fn new(path: &str, config: DatabaseConfig) -> ArchiveDB {
+		let opts = config.prefix(DB_PREFIX_LEN);
 		let backing = Database::open(&opts, path).unwrap_or_else(|e| {
 			panic!("Error opening state db: {}", e);
 		});
diff --git a/util/src/journaldb/earlymergedb.rs b/util/src/journaldb/earlymergedb.rs
index 71959fa35..5c267679b 100644
--- a/util/src/journaldb/earlymergedb.rs
+++ b/util/src/journaldb/earlymergedb.rs
@@ -73,13 +73,8 @@ const PADDING : [u8; 10] = [ 0u8; 10 ];
 
 impl EarlyMergeDB {
 	/// Create a new instance from file
-	pub fn new(path: &str, cache_size: Option<usize>) -> EarlyMergeDB {
-		let opts = DatabaseConfig {
-			// this must match account_db prefix
-			prefix_size: Some(DB_PREFIX_LEN),
-			max_open_files: 256,
-			cache_size: cache_size,
-		};
+	pub fn new(path: &str, config: DatabaseConfig) -> EarlyMergeDB {
+		let opts = config.prefix(DB_PREFIX_LEN);
 		let backing = Database::open(&opts, path).unwrap_or_else(|e| {
 			panic!("Error opening state db: {}", e);
 		});
diff --git a/util/src/journaldb/mod.rs b/util/src/journaldb/mod.rs
index 973dd9eb0..4715273dd 100644
--- a/util/src/journaldb/mod.rs
+++ b/util/src/journaldb/mod.rs
@@ -17,6 +17,7 @@
 //! `JournalDB` interface and implementation.
 
 use common::*;
+use kvdb::DatabaseConfig;
 
 /// Export the journaldb module.
 pub mod traits;
@@ -71,12 +72,12 @@ impl fmt::Display for Algorithm {
 }
 
 /// Create a new `JournalDB` trait object.
-pub fn new(path: &str, algorithm: Algorithm, cache_size: Option<usize>) -> Box<JournalDB> {
+pub fn new(path: &str, algorithm: Algorithm, config: DatabaseConfig) -> Box<JournalDB> {
 	match algorithm {
-		Algorithm::Archive => Box::new(archivedb::ArchiveDB::new(path, cache_size)),
-		Algorithm::EarlyMerge => Box::new(earlymergedb::EarlyMergeDB::new(path, cache_size)),
-		Algorithm::OverlayRecent => Box::new(overlayrecentdb::OverlayRecentDB::new(path, cache_size)),
-		Algorithm::RefCounted => Box::new(refcounteddb::RefCountedDB::new(path, cache_size)),
+		Algorithm::Archive => Box::new(archivedb::ArchiveDB::new(path, config)),
+		Algorithm::EarlyMerge => Box::new(earlymergedb::EarlyMergeDB::new(path, config)),
+		Algorithm::OverlayRecent => Box::new(overlayrecentdb::OverlayRecentDB::new(path, config)),
+		Algorithm::RefCounted => Box::new(refcounteddb::RefCountedDB::new(path, config)),
 	}
 }
 
diff --git a/util/src/journaldb/overlayrecentdb.rs b/util/src/journaldb/overlayrecentdb.rs
index 158b771fb..09ec3da88 100644
--- a/util/src/journaldb/overlayrecentdb.rs
+++ b/util/src/journaldb/overlayrecentdb.rs
@@ -98,18 +98,13 @@ const PADDING : [u8; 10] = [ 0u8; 10 ];
 
 impl OverlayRecentDB {
 	/// Create a new instance from file
-	pub fn new(path: &str, cache_size: Option<usize>) -> OverlayRecentDB {
-		Self::from_prefs(path, cache_size)
+	pub fn new(path: &str, config: DatabaseConfig) -> OverlayRecentDB {
+		Self::from_prefs(path, config)
 	}
 
 	/// Create a new instance from file
-	pub fn from_prefs(path: &str, cache_size: Option<usize>) -> OverlayRecentDB {
-		let opts = DatabaseConfig {
-			// this must match account_db prefix
-			prefix_size: Some(DB_PREFIX_LEN),
-			max_open_files: 256,
-			cache_size: cache_size,
-		};
+	pub fn from_prefs(path: &str, config: DatabaseConfig) -> OverlayRecentDB {
+		let opts = config.prefix(DB_PREFIX_LEN);
 		let backing = Database::open(&opts, path).unwrap_or_else(|e| {
 			panic!("Error opening state db: {}", e);
 		});
diff --git a/util/src/journaldb/refcounteddb.rs b/util/src/journaldb/refcounteddb.rs
index fc7da1541..d2092b2a6 100644
--- a/util/src/journaldb/refcounteddb.rs
+++ b/util/src/journaldb/refcounteddb.rs
@@ -46,13 +46,8 @@ const PADDING : [u8; 10] = [ 0u8; 10 ];
 
 impl RefCountedDB {
 	/// Create a new instance given a `backing` database.
-	pub fn new(path: &str, cache_size: Option<usize>) -> RefCountedDB {
-		let opts = DatabaseConfig {
-			// this must match account_db prefix
-			prefix_size: Some(DB_PREFIX_LEN),
-			max_open_files: 256,
-			cache_size: cache_size,
-		};
+	pub fn new(path: &str, config: DatabaseConfig) -> RefCountedDB {
+		let opts = config.prefix(DB_PREFIX_LEN);
 		let backing = Database::open(&opts, path).unwrap_or_else(|e| {
 			panic!("Error opening state db: {}", e);
 		});
diff --git a/util/src/kvdb.rs b/util/src/kvdb.rs
index 10c7a3276..9cf4313f2 100644
--- a/util/src/kvdb.rs
+++ b/util/src/kvdb.rs
@@ -104,11 +104,13 @@ impl DatabaseConfig {
 		}
 	}
 
+	/// Modify the compaction profile
 	pub fn compaction(mut self, profile: CompactionProfile) -> Self {
 		self.compaction = profile;
 		self
 	}
 
+	/// Modify the prefix of the db
 	pub fn prefix(mut self, prefix_size: usize) -> Self {
 		self.prefix_size = Some(prefix_size);
 		self