diff --git a/src/com/audacious_software/passive_data_kit/activities/DataStreamActivity.java b/src/com/audacious_software/passive_data_kit/activities/DataStreamActivity.java
index ec746cb..cf46906 100755
--- a/src/com/audacious_software/passive_data_kit/activities/DataStreamActivity.java
+++ b/src/com/audacious_software/passive_data_kit/activities/DataStreamActivity.java
@@ -8,6 +8,7 @@
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
+import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 
@@ -69,6 +70,8 @@ protected void onPause() {
 
     @Override
     public void onGeneratorUpdated(final String identifier, long timestamp, Bundle data) {
+        Log.e("PDK", "GENERATOR UPDATED: " + identifier);
+
         final DataStreamActivity me = this;
 
         if (me.mIsUpdating) {
diff --git a/src/com/audacious_software/passive_data_kit/generators/Generator.java b/src/com/audacious_software/passive_data_kit/generators/Generator.java
index 24a926c..dffde32 100755
--- a/src/com/audacious_software/passive_data_kit/generators/Generator.java
+++ b/src/com/audacious_software/passive_data_kit/generators/Generator.java
@@ -22,7 +22,7 @@
 public abstract class Generator
 {
     public static final String PDK_METADATA = "passive-data-metadata";
-    public static final java.lang.String IDENTIFIER = "generator-id";
+    public static final String IDENTIFIER = "generator-id";
     public static final String TIMESTAMP = "timestamp";
     public static final String GENERATOR = "generator";
     public static final String SOURCE = "source";
@@ -184,4 +184,7 @@ protected void setDatabaseVersion(SQLiteDatabase db, int newVersion) {
             db.insert(Generator.TABLE_METADATA, null, values);
         }
     }
+
+    protected abstract void flushCachedData();
+    public abstract void setCachedDataRetentionPeriod(long period);
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/communication/PhoneCalls.java b/src/com/audacious_software/passive_data_kit/generators/communication/PhoneCalls.java
index c6db0e9..79be732 100755
--- a/src/com/audacious_software/passive_data_kit/generators/communication/PhoneCalls.java
+++ b/src/com/audacious_software/passive_data_kit/generators/communication/PhoneCalls.java
@@ -14,6 +14,7 @@
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
+import android.preference.PreferenceManager;
 import android.provider.CallLog;
 import android.support.v4.content.ContextCompat;
 import android.util.Log;
@@ -53,6 +54,9 @@ public class PhoneCalls extends Generator {
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.communication.PhoneCalls.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.communication.PhoneCalls.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static final String CALL_DATE_KEY = "call_timestamp";
     private static final String CALL_DURATION_KEY = "duration";
     private static final String CALL_IS_NEW_KEY = "is_new";
@@ -355,6 +359,8 @@ public void run() {
         me.mHandler.post(checkLogs);
 
         Generators.getInstance(this.mContext).registerCustomViewClass(PhoneCalls.GENERATOR_IDENTIFIER, PhoneCalls.class);
+
+        this.flushCachedData();
     }
 
     @SuppressWarnings("unused")
@@ -535,6 +541,30 @@ public List<Bundle> fetchPayloads() {
         return new ArrayList<>();
     }
 
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(PhoneCalls.DATA_RETENTION_PERIOD, PhoneCalls.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = PhoneCalls.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(PhoneCalls.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(PhoneCalls.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
+
     @SuppressWarnings("unused")
     public static View fetchView(ViewGroup parent)
     {
diff --git a/src/com/audacious_software/passive_data_kit/generators/communication/TextMessages.java b/src/com/audacious_software/passive_data_kit/generators/communication/TextMessages.java
index dce5d84..f162b47 100755
--- a/src/com/audacious_software/passive_data_kit/generators/communication/TextMessages.java
+++ b/src/com/audacious_software/passive_data_kit/generators/communication/TextMessages.java
@@ -14,6 +14,7 @@
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
+import android.preference.PreferenceManager;
 import android.support.v4.content.ContextCompat;
 import android.util.Log;
 import android.view.LayoutInflater;
@@ -54,6 +55,9 @@ public class TextMessages extends Generator {
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.communication.TextMessages.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.communication.TextMessages.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static final Uri SMS_INBOX_URI = Uri.parse("content://sms/inbox");
     private static final Uri SMS_SENT_URI = Uri.parse("content://sms/sent");
 
@@ -301,6 +305,8 @@ public void run() {
         me.mHandler.post(checkLogs);
 
         Generators.getInstance(this.mContext).registerCustomViewClass(TextMessages.GENERATOR_IDENTIFIER, TextMessages.class);
+
+        this.flushCachedData();
     }
 
     @SuppressWarnings("unused")
@@ -458,6 +464,30 @@ public String getFormattedValue(float value, Entry entry, int dataSetIndex, View
         }
     }
 
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(TextMessages.DATA_RETENTION_PERIOD, TextMessages.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = TextMessages.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(TextMessages.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(TextMessages.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
+
     @Override
     public List<Bundle> fetchPayloads() {
         return new ArrayList<>();
diff --git a/src/com/audacious_software/passive_data_kit/generators/device/Battery.java b/src/com/audacious_software/passive_data_kit/generators/device/Battery.java
index 0cb78e6..aee2a23 100755
--- a/src/com/audacious_software/passive_data_kit/generators/device/Battery.java
+++ b/src/com/audacious_software/passive_data_kit/generators/device/Battery.java
@@ -10,6 +10,7 @@
 import android.database.sqlite.SQLiteDatabase;
 import android.os.BatteryManager;
 import android.os.Bundle;
+import android.preference.PreferenceManager;
 import android.support.v4.content.ContextCompat;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -45,6 +46,8 @@ public class Battery extends Generator {
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.device.Battery.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.device.Battery.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
 
     private static final String DATABASE_PATH = "pdk-device-battery.sqlite";
     private static final int DATABASE_VERSION = 1;
@@ -102,6 +105,7 @@ public class Battery extends Generator {
 
     private int mLastLevel = -1;
     private int mLastStatus = BatteryManager.BATTERY_STATUS_UNKNOWN;
+    private int mLastScale = -1;
 
     private int mLastHealth = BatteryManager.BATTERY_HEALTH_UNKNOWN;
     private int mLastPlugged = -1;
@@ -278,8 +282,9 @@ public void onReceive(final Context context, Intent intent) {
                     values.put(Battery.HISTORY_LEVEL, level);
                     update.putInt(Battery.HISTORY_LEVEL, level);
 
-                    values.put(Battery.HISTORY_SCALE, intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1));
-                    update.putInt(Battery.HISTORY_SCALE, intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1));
+                    int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
+                    values.put(Battery.HISTORY_SCALE, scale);
+                    update.putInt(Battery.HISTORY_SCALE, scale);
 
                     values.put(Battery.HISTORY_TEMPERATURE, temperature);
                     update.putInt(Battery.HISTORY_TEMPERATURE, temperature);
@@ -306,6 +311,7 @@ public void onReceive(final Context context, Intent intent) {
                     }
 
                     me.mLastLevel = level;
+                    me.mLastScale = scale;
                     me.mLastStatus = status;
                     me.mLastHealth = health;
                     me.mLastPlugged = plugged;
@@ -335,6 +341,8 @@ public void onReceive(final Context context, Intent intent) {
 
         IntentFilter filter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
         this.mContext.registerReceiver(this.mReceiver, filter);
+
+        this.flushCachedData();
     }
 
     @SuppressWarnings("unused")
@@ -534,4 +542,36 @@ public void setMonitorsTemperature(boolean monitorTemperature) {
     public void setMinUpdateInterval(long updateInterval) {
         this.mMinUpdateInterval = updateInterval;
     }
+
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(Battery.DATA_RETENTION_PERIOD, Battery.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = Battery.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(Battery.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(Battery.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
+
+    public int getLastLevel() {
+        return this.mLastLevel;
+    }
+
+    public int getLastScale() {
+        return this.mLastScale;
+    }
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/device/ForegroundApplication.java b/src/com/audacious_software/passive_data_kit/generators/device/ForegroundApplication.java
index ac93f94..b7faa20 100755
--- a/src/com/audacious_software/passive_data_kit/generators/device/ForegroundApplication.java
+++ b/src/com/audacious_software/passive_data_kit/generators/device/ForegroundApplication.java
@@ -12,8 +12,8 @@
 import android.graphics.drawable.Drawable;
 import android.os.Build;
 import android.os.Bundle;
+import android.preference.PreferenceManager;
 import android.provider.Settings;
-import android.util.Log;
 import android.view.Display;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -47,6 +47,9 @@ public class ForegroundApplication extends Generator{
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.device.ForegroundApplication.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.device.ForegroundApplication.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static final int DATABASE_VERSION = 3;
 
     private static final String TABLE_HISTORY = "history";
@@ -128,8 +131,6 @@ public void onForeground(String process) {
                 update.putLong(ForegroundApplication.HISTORY_DURATION, me.mSampleInterval);
                 update.putBoolean(ForegroundApplication.HISTORY_SCREEN_ACTIVE, screenActive);
 
-                Log.e("SLEEP-SIGHT", "TRANSMIT BUNDLE: " + update);
-
                 Generators.getInstance(me.mContext).notifyGeneratorUpdated(ForegroundApplication.GENERATOR_IDENTIFIER, update);
             }
         });
@@ -157,6 +158,8 @@ public void onForeground(String process) {
         this.setDatabaseVersion(this.mDatabase, ForegroundApplication.DATABASE_VERSION);
 
         Generators.getInstance(this.mContext).registerCustomViewClass(ForegroundApplication.GENERATOR_IDENTIFIER, ForegroundApplication.class);
+
+        this.flushCachedData();
     }
 
     @SuppressWarnings("unused")
@@ -212,15 +215,17 @@ public static void bindDisclosureViewHolder(final GeneratorViewHolder holder) {
 
     @SuppressWarnings("unused")
     public static void bindViewHolder(DataPointViewHolder holder) {
+        long start = System.currentTimeMillis();
+
         final Context context = holder.itemView.getContext();
 
         long lastTimestamp = 0;
 
         ForegroundApplication generator = ForegroundApplication.getInstance(holder.itemView.getContext());
 
-        Cursor c = generator.mDatabase.query(ForegroundApplication.TABLE_HISTORY, null, null, null, null, null, ForegroundApplication.HISTORY_OBSERVED + " DESC");
+        Cursor c = generator.mDatabase.query(ForegroundApplication.TABLE_HISTORY, null, null, null, null, null, ForegroundApplication.HISTORY_OBSERVED + " DESC", "1");
 
-        while (c.moveToNext()) {
+        if (c.moveToNext()) {
             if (lastTimestamp == 0) {
                 lastTimestamp = c.getLong(c.getColumnIndex(ForegroundApplication.HISTORY_OBSERVED));
             }
@@ -407,13 +412,37 @@ public int compare(HashMap<String, Double> mapOne, HashMap<String, Double> mapTw
 
             dateLabel.setText(R.string.label_never_pdk);
         }
-    }
+   }
 
     @Override
     public List<Bundle> fetchPayloads() {
         return new ArrayList<>();
     }
 
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(ForegroundApplication.DATA_RETENTION_PERIOD, ForegroundApplication.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = ForegroundApplication.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(ForegroundApplication.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(ForegroundApplication.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
+
     @SuppressWarnings("unused")
     public static View fetchView(ViewGroup parent)
     {
diff --git a/src/com/audacious_software/passive_data_kit/generators/device/Location.java b/src/com/audacious_software/passive_data_kit/generators/device/Location.java
index 174bf7a..05851f9 100755
--- a/src/com/audacious_software/passive_data_kit/generators/device/Location.java
+++ b/src/com/audacious_software/passive_data_kit/generators/device/Location.java
@@ -81,6 +81,9 @@ public class Location extends Generator implements GoogleApiClient.ConnectionCal
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.device.Location.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.device.Location.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static final String USE_GOOGLE_SERVICES = "com.audacious_software.passive_data_kit.generators.device.Location.USE_GOOGLE_SERVICES";
     private static final boolean USE_GOOGLE_SERVICES_DEFAULT = true;
 
@@ -435,6 +438,8 @@ public void onLocationChanged(android.location.Location location) {
         this.mDatabase.insert(Location.TABLE_HISTORY, null, values);
 
         Generators.getInstance(this.mContext).notifyGeneratorUpdated(Location.GENERATOR_IDENTIFIER, updated);
+
+        this.flushCachedData();
     }
 
     @SuppressWarnings("unused")
@@ -1078,4 +1083,28 @@ public void setPreservesRandomVector(boolean preservesVector) {
 
         e.apply();
     }
+
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(Location.DATA_RETENTION_PERIOD, Location.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = Location.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(Location.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(Location.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/device/ScreenState.java b/src/com/audacious_software/passive_data_kit/generators/device/ScreenState.java
index 6935449..d7faf1d 100755
--- a/src/com/audacious_software/passive_data_kit/generators/device/ScreenState.java
+++ b/src/com/audacious_software/passive_data_kit/generators/device/ScreenState.java
@@ -10,6 +10,7 @@
 import android.database.sqlite.SQLiteDatabase;
 import android.os.Build;
 import android.os.Bundle;
+import android.preference.PreferenceManager;
 import android.view.Display;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -39,6 +40,9 @@ public class ScreenState extends Generator{
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.device.ScreenState.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.device.ScreenState.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     @SuppressWarnings("WeakerAccess")
     public static final String STATE_DOZE = "doze";
 
@@ -172,6 +176,8 @@ public void onReceive(final Context context, Intent intent) {
         }
 
         this.setDatabaseVersion(this.mDatabase, ScreenState.DATABASE_VERSION);
+
+        this.flushCachedData();
     }
 
     @SuppressWarnings("unused")
@@ -476,4 +482,28 @@ public static long latestPointGenerated(Context context) {
     public Cursor queryHistory(String[] cols, String where, String[] args, String orderBy) {
         return this.mDatabase.query(ScreenState.TABLE_HISTORY, cols, where, args, null, null, orderBy);
     }
+
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(ScreenState.DATA_RETENTION_PERIOD, ScreenState.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = ScreenState.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(ScreenState.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(ScreenState.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/diagnostics/AppEvent.java b/src/com/audacious_software/passive_data_kit/generators/diagnostics/AppEvent.java
index 0a9d47a..df3e75f 100755
--- a/src/com/audacious_software/passive_data_kit/generators/diagnostics/AppEvent.java
+++ b/src/com/audacious_software/passive_data_kit/generators/diagnostics/AppEvent.java
@@ -6,6 +6,7 @@
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.os.Bundle;
+import android.preference.PreferenceManager;
 import android.support.v4.view.PagerAdapter;
 import android.support.v4.view.ViewPager;
 import android.view.LayoutInflater;
@@ -41,6 +42,9 @@ public class AppEvent extends Generator{
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.diagnostics.AppEvent.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.diagnostics.AppEvent.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static final String DATABASE_PATH = "pdk-app-event.sqlite";
     private static final int DATABASE_VERSION = 1;
 
@@ -107,6 +111,8 @@ private void startGenerator() {
         }
 
         this.setDatabaseVersion(this.mDatabase, AppEvent.DATABASE_VERSION);
+
+        this.flushCachedData();
     }
 
     @SuppressWarnings("unused")
@@ -441,4 +447,28 @@ public static View getDisclosureDataView(final GeneratorViewHolder holder) {
 
         return disclosureView;
     }
+
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(AppEvent.DATA_RETENTION_PERIOD, AppEvent.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = AppEvent.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(AppEvent.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(AppEvent.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/diagnostics/SystemStatus.java b/src/com/audacious_software/passive_data_kit/generators/diagnostics/SystemStatus.java
index 32d9750..ab32e66 100755
--- a/src/com/audacious_software/passive_data_kit/generators/diagnostics/SystemStatus.java
+++ b/src/com/audacious_software/passive_data_kit/generators/diagnostics/SystemStatus.java
@@ -14,6 +14,7 @@
 import android.os.Build;
 import android.os.Bundle;
 import android.os.StatFs;
+import android.preference.PreferenceManager;
 import android.support.v4.content.ContextCompat;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -51,6 +52,9 @@ public class SystemStatus extends Generator {
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.diagnostics.SystemStatus.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.diagnostics.SystemStatus.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static final String ACTION_HEARTBEAT = "com.audacious_software.passive_data_kit.generators.diagnostics.SystemStatus.ACTION_HEARTBEAT";
 
     private static final String DATABASE_PATH = "pdk-system-status.sqlite";
@@ -186,6 +190,8 @@ public void onReceive(Context context, Intent intent) {
 
         IntentFilter filter = new IntentFilter(SystemStatus.ACTION_HEARTBEAT);
         this.mContext.registerReceiver(this.mReceiver, filter);
+
+        this.flushCachedData();
     }
 
     @SuppressWarnings("unused")
@@ -488,4 +494,28 @@ public static long latestPointGenerated(Context context) {
     public Cursor queryHistory(String[] cols, String where, String[] args, String orderBy) {
         return this.mDatabase.query(SystemStatus.TABLE_HISTORY, cols, where, args, null, null, orderBy);
     }
+
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(SystemStatus.DATA_RETENTION_PERIOD, SystemStatus.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = SystemStatus.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(SystemStatus.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(SystemStatus.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/sensors/Accelerometer.java b/src/com/audacious_software/passive_data_kit/generators/sensors/Accelerometer.java
index 6d97746..ba12cb4 100755
--- a/src/com/audacious_software/passive_data_kit/generators/sensors/Accelerometer.java
+++ b/src/com/audacious_software/passive_data_kit/generators/sensors/Accelerometer.java
@@ -54,6 +54,9 @@ public class Accelerometer extends SensorGenerator implements SensorEventListene
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.device.Accelerometer.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.sensors.Accelerometer.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static final String IGNORE_POWER_MANAGEMENT = "com.audacious_software.passive_data_kit.generators.sensors.Accelerometer.IGNORE_POWER_MANAGEMENT";
     private static final boolean IGNORE_POWER_MANAGEMENT_DEFAULT = true;
 
@@ -270,6 +273,8 @@ public void run() {
         } else {
             this.stopGenerator();
         }
+
+        this.flushCachedData();
     }
 
     private void stopGenerator() {
@@ -778,4 +783,28 @@ public void run() {
     public void onAccuracyChanged(Sensor sensor, int newAccuracy) {
         // Do nothing...
     }
+
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(Accelerometer.DATA_RETENTION_PERIOD, Accelerometer.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = Accelerometer.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(Accelerometer.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(Accelerometer.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/sensors/AmbientLight.java b/src/com/audacious_software/passive_data_kit/generators/sensors/AmbientLight.java
index 54b23bb..a629dee 100755
--- a/src/com/audacious_software/passive_data_kit/generators/sensors/AmbientLight.java
+++ b/src/com/audacious_software/passive_data_kit/generators/sensors/AmbientLight.java
@@ -54,6 +54,9 @@ public class AmbientLight extends SensorGenerator implements SensorEventListener
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.device.AmbientLight.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.sensors.AmbientLight.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static final String IGNORE_POWER_MANAGEMENT = "com.audacious_software.passive_data_kit.generators.sensors.AmbientLight.IGNORE_POWER_MANAGEMENT";
     private static final boolean IGNORE_POWER_MANAGEMENT_DEFAULT = true;
 
@@ -191,6 +194,8 @@ public void run()
         } else {
             this.stopGenerator();
         }
+
+        this.flushCachedData();
     }
 
     private void stopGenerator() {
@@ -610,4 +615,28 @@ public void run() {
     public void onAccuracyChanged(Sensor sensor, int newAccuracy) {
         // Do nothing...
     }
+
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(AmbientLight.DATA_RETENTION_PERIOD, AmbientLight.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = AmbientLight.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(AmbientLight.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(AmbientLight.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/services/GoogleAwareness.java b/src/com/audacious_software/passive_data_kit/generators/services/GoogleAwareness.java
index bcb78cb..beb2123 100755
--- a/src/com/audacious_software/passive_data_kit/generators/services/GoogleAwareness.java
+++ b/src/com/audacious_software/passive_data_kit/generators/services/GoogleAwareness.java
@@ -8,9 +8,11 @@
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
+import android.preference.PreferenceManager;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v4.content.ContextCompat;
+import android.util.Log;
 
 import com.audacious_software.passive_data_kit.activities.generators.RequestPermissionActivity;
 import com.audacious_software.passive_data_kit.diagnostics.DiagnosticAction;
@@ -32,6 +34,10 @@ public class GoogleAwareness extends Generator implements GoogleApiClient.Connec
 
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.services.GoogleAwareness.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
+
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.services.GoogleAwareness.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static final long SENSING_INTERVAL = 60 * 1000;
 
     private static GoogleAwareness sInstance = null;
@@ -81,6 +87,8 @@ public void run() {
         t.start();
 
         Generators.getInstance(this.mContext).registerCustomViewClass(GoogleAwareness.GENERATOR_IDENTIFIER, GoogleAwareness.class);
+
+        this.flushCachedData();
     }
 
     @SuppressWarnings("unused")
@@ -204,4 +212,30 @@ public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
     public List<Bundle> fetchPayloads() {
         return new ArrayList<>();
     }
+
+    @Override
+    protected void flushCachedData() {
+        Log.e("PDK", "TODO: Implement data cache flush in GoogleAwareness!");
+
+//        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+//
+//        long retentionPeriod = prefs.getLong(GoogleAwareness.DATA_RETENTION_PERIOD, GoogleAwareness.DATA_RETENTION_PERIOD_DEFAULT);
+//
+//        long start = System.currentTimeMillis() - retentionPeriod;
+//
+//        String where = GoogleAwareness.HISTORY_OBSERVED + " < ?";
+//        String[] args = { "" + start };
+//
+//        this.mDatabase.delete(GoogleAwareness.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(GoogleAwareness.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/vr/DaydreamViewController.java b/src/com/audacious_software/passive_data_kit/generators/vr/DaydreamViewController.java
index 9921689..bbd8b5b 100755
--- a/src/com/audacious_software/passive_data_kit/generators/vr/DaydreamViewController.java
+++ b/src/com/audacious_software/passive_data_kit/generators/vr/DaydreamViewController.java
@@ -4,6 +4,8 @@
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.os.Bundle;
+import android.preference.PreferenceManager;
+import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -26,6 +28,9 @@ public class DaydreamViewController extends Generator  {
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.vr.DaydreamViewController.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.vr.DaydreamViewController.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static DaydreamViewController sInstance = null;
 
     private BroadcastReceiver mReceiver = null;
@@ -84,6 +89,8 @@ public void onUpdate() {
 
     private void startGenerator() {
         Generators.getInstance(this.mContext).registerCustomViewClass(DaydreamViewController.GENERATOR_IDENTIFIER, DaydreamViewController.class);
+
+        this.flushCachedData();
     }
 
     @SuppressWarnings("unused")
@@ -187,4 +194,31 @@ public List<Bundle> fetchPayloads() {
     public static void broadcastLatestDataPoint(Context context) {
 //        Generators.getInstance(context).transmitData(DaydreamViewController.GENERATOR_IDENTIFIER, new Bundle());
     }
+
+    @Override
+    protected void flushCachedData() {
+        Log.e("PDK", "TODO: Implement data cache flush in DaydreamViewController!");
+
+//        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+//
+//        long retentionPeriod = prefs.getLong(GoogleAwareness.DATA_RETENTION_PERIOD, GoogleAwareness.DATA_RETENTION_PERIOD_DEFAULT);
+//
+//        long start = System.currentTimeMillis() - retentionPeriod;
+//
+//        String where = GoogleAwareness.HISTORY_OBSERVED + " < ?";
+//        String[] args = { "" + start };
+//
+//        this.mDatabase.delete(GoogleAwareness.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(DaydreamViewController.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
+
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/wearables/MicrosoftBand.java b/src/com/audacious_software/passive_data_kit/generators/wearables/MicrosoftBand.java
index 1b9e88d..4346a20 100755
--- a/src/com/audacious_software/passive_data_kit/generators/wearables/MicrosoftBand.java
+++ b/src/com/audacious_software/passive_data_kit/generators/wearables/MicrosoftBand.java
@@ -6,7 +6,9 @@
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
+import android.preference.PreferenceManager;
 import android.support.annotation.NonNull;
+import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -71,9 +73,13 @@
 @SuppressWarnings("SimplifiableIfStatement")
 public class MicrosoftBand extends Generator
 {
+    private static final String GENERATOR_IDENTIFIER = "pdk-microsoft-band";
+
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.wearables.MicrosoftBand.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
-    private static final String GENERATOR_IDENTIFIER = "pdk-microsoft-band";
+
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.wearables.MicrosoftBand.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
 
     private static final String TIMESTAMP_KEY = "timestamps";
     private static final String X_KEY = "xs";
@@ -1445,4 +1451,31 @@ public static void bindViewHolder(DataPointViewHolder holder, Bundle dataPoint)
     public List<Bundle> fetchPayloads() {
         return new ArrayList<>();
     }
+
+    @Override
+    protected void flushCachedData() {
+        Log.e("PDK", "TODO: Implement data cache flush in MicrosoftBand!");
+
+//        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+//
+//        long retentionPeriod = prefs.getLong(MicrosoftBand.DATA_RETENTION_PERIOD, MicrosoftBand.DATA_RETENTION_PERIOD_DEFAULT);
+//
+//        long start = System.currentTimeMillis() - retentionPeriod;
+//
+//        String where = MicrosoftBand.HISTORY_OBSERVED + " < ?";
+//        String[] args = { "" + start };
+//
+//        this.mDatabase.delete(MicrosoftBand.TABLE_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(MicrosoftBand.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
+
 }
diff --git a/src/com/audacious_software/passive_data_kit/generators/wearables/WithingsDevice.java b/src/com/audacious_software/passive_data_kit/generators/wearables/WithingsDevice.java
index cb9e9b3..cebd42f 100755
--- a/src/com/audacious_software/passive_data_kit/generators/wearables/WithingsDevice.java
+++ b/src/com/audacious_software/passive_data_kit/generators/wearables/WithingsDevice.java
@@ -80,6 +80,9 @@ public class WithingsDevice extends Generator {
     private static final String ENABLED = "com.audacious_software.passive_data_kit.generators.wearables.WithingsDevice.ENABLED";
     private static final boolean ENABLED_DEFAULT = true;
 
+    private static final String DATA_RETENTION_PERIOD = "com.audacious_software.passive_data_kit.generators.wearables.WithingsDevice.DATA_RETENTION_PERIOD";
+    private static final long DATA_RETENTION_PERIOD_DEFAULT = (60 * 24 * 60 * 60 * 1000);
+
     private static final String DATASTREAM = "datastream";
     private static final String DATASTREAM_ACTIVITY_MEASURES = "activity-measures";
     private static final String DATASTREAM_INTRADAY_ACTIVITY = "intraday-activity";
@@ -386,6 +389,8 @@ public void run() {
         me.mHandler.post(fetchData);
 
         Generators.getInstance(this.mContext).registerCustomViewClass(WithingsDevice.GENERATOR_IDENTIFIER, WithingsDevice.class);
+
+        this.flushCachedData();
     }
 
     private String getProperty(String key) {
@@ -1866,4 +1871,34 @@ public void enableServerFetch(boolean enable) {
 
         e.apply();
     }
+
+    @Override
+    protected void flushCachedData() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+
+        long retentionPeriod = prefs.getLong(WithingsDevice.DATA_RETENTION_PERIOD, WithingsDevice.DATA_RETENTION_PERIOD_DEFAULT);
+
+        long start = System.currentTimeMillis() - retentionPeriod;
+
+        String where = WithingsDevice.HISTORY_OBSERVED + " < ?";
+        String[] args = { "" + start };
+
+        this.mDatabase.delete(WithingsDevice.TABLE_ACTIVITY_MEASURE_HISTORY, where, args);
+        this.mDatabase.delete(WithingsDevice.TABLE_SLEEP_MEASURE_HISTORY, where, args);
+        this.mDatabase.delete(WithingsDevice.TABLE_BODY_MEASURE_HISTORY, where, args);
+        this.mDatabase.delete(WithingsDevice.TABLE_INTRADAY_ACTIVITY_HISTORY, where, args);
+        this.mDatabase.delete(WithingsDevice.TABLE_SLEEP_SUMMARY_HISTORY, where, args);
+        this.mDatabase.delete(WithingsDevice.TABLE_WORKOUT_HISTORY, where, args);
+    }
+
+    @Override
+    public void setCachedDataRetentionPeriod(long period) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.mContext);
+        SharedPreferences.Editor e = prefs.edit();
+
+        e.putLong(WithingsDevice.DATA_RETENTION_PERIOD, period);
+
+        e.apply();
+    }
 }
+