diff --git a/app/src/main/java/com/geeksville/mesh/ui/MapFragment.kt b/app/src/main/java/com/geeksville/mesh/ui/MapFragment.kt
index a910cef7..e3d334fb 100644
--- a/app/src/main/java/com/geeksville/mesh/ui/MapFragment.kt
+++ b/app/src/main/java/com/geeksville/mesh/ui/MapFragment.kt
@@ -22,6 +22,8 @@ import com.geeksville.mesh.databinding.MapViewBinding
 import com.geeksville.mesh.model.UIViewModel
 import com.geeksville.mesh.model.map.CustomOverlayManager
 import com.geeksville.mesh.model.map.CustomTileSource
+import com.geeksville.mesh.util.SqlTileWriterExt
+import com.geeksville.mesh.util.SqlTileWriterExt.SourceCount
 import com.geeksville.mesh.util.formatAgo
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import com.google.android.material.floatingactionbutton.FloatingActionButton
@@ -60,6 +62,7 @@ class MapFragment : ScreenFragment("Map"), Logging, View.OnClickListener {
     private lateinit var executeJob: Button
     private var downloadPrompt: AlertDialog? = null
     private var alertDialog: AlertDialog? = null
+    private var cache: SqlTileWriterExt? = null
 
     // constants
     private val defaultMinZoom = 1.5
@@ -170,7 +173,7 @@ class MapFragment : ScreenFragment("Map"), Logging, View.OnClickListener {
                     downloadJobAlert()
                     dialog.dismiss()
                 }
-                2 -> clearCache()
+                2 -> purgeTileSource()
                 else -> dialog.dismiss()
             }
         }
@@ -181,6 +184,7 @@ class MapFragment : ScreenFragment("Map"), Logging, View.OnClickListener {
         alertDialog!!.show()
 
     }
+
     /**
      * Clears active tile source cache
      */
@@ -193,6 +197,36 @@ class MapFragment : ScreenFragment("Map"), Logging, View.OnClickListener {
         alertDialog!!.dismiss()
     }
 
+    private fun purgeTileSource() {
+        cache = SqlTileWriterExt()
+        val builder = AlertDialog.Builder(context)
+        builder.setTitle("Tile Source")
+        val arrayAdapter: ArrayAdapter<String> =
+            ArrayAdapter(context!!, android.R.layout.select_dialog_singlechoice)
+        val sources = cache!!.sources
+        for (i in sources.indices) {
+            arrayAdapter.add(sources[i].source)
+        }
+        builder.setAdapter(arrayAdapter) { dialog, which ->
+            val item = arrayAdapter.getItem(which)
+            val b = cache!!.purgeCache(item)
+            if (b) Toast.makeText(
+                context,
+                "SQL Cache purged",
+                Toast.LENGTH_SHORT
+            )
+                .show() else Toast.makeText(
+                context,
+                "SQL Cache purge failed, see logcat for details",
+                Toast.LENGTH_LONG
+            ).show()
+        }
+        builder.setNegativeButton(
+            "Cancel"
+        ) { dialog, which -> dialog.cancel() }
+        builder.show()
+    }
+
 
     private fun showCurrentCacheInfo() {
         Toast.makeText(activity, "Calculating...", Toast.LENGTH_SHORT).show()
diff --git a/app/src/main/java/com/geeksville/mesh/util/SqlTileWriterExt.kt b/app/src/main/java/com/geeksville/mesh/util/SqlTileWriterExt.kt
new file mode 100644
index 00000000..edeea830
--- /dev/null
+++ b/app/src/main/java/com/geeksville/mesh/util/SqlTileWriterExt.kt
@@ -0,0 +1,81 @@
+package com.geeksville.mesh.util
+
+import android.database.Cursor
+import org.osmdroid.tileprovider.modules.DatabaseFileArchive
+import org.osmdroid.tileprovider.modules.SqlTileWriter
+
+
+/**
+ * Extended the sqlite tile writer to have some additional query functions. A this point
+ * it's unclear if there is a need to put these with the osmdroid-android library, thus they were
+ * put here as more of an example.
+ *
+ *
+ * created on 12/21/2016.
+ *
+ * @author Alex O'Ree
+ * @since 5.6.2
+ */
+class SqlTileWriterExt() : SqlTileWriter() {
+    fun select(rows: Int, offset: Int): Cursor? {
+        return this.db?.rawQuery(
+            "select " + DatabaseFileArchive.COLUMN_KEY + "," + COLUMN_EXPIRES + "," + DatabaseFileArchive.COLUMN_PROVIDER + " from " + DatabaseFileArchive.TABLE + " limit ? offset ?",
+            arrayOf(rows.toString() + "", offset.toString() + "")
+        )
+    }
+
+    /**
+     * gets all the tiles sources that we have tiles for in the cache database and their counts
+     *
+     * @return
+     */
+    val sources: List<SourceCount>
+        get() {
+            val db = db
+            val ret: MutableList<SourceCount> = ArrayList()
+            if (db == null) {
+                return ret
+            }
+            var cur: Cursor? = null
+            try {
+                cur = db.rawQuery(
+                    "select "
+                            + DatabaseFileArchive.COLUMN_PROVIDER
+                            + ",count(*) "
+                            + ",min(length(" + DatabaseFileArchive.COLUMN_TILE + ")) "
+                            + ",max(length(" + DatabaseFileArchive.COLUMN_TILE + ")) "
+                            + ",sum(length(" + DatabaseFileArchive.COLUMN_TILE + ")) "
+                            + "from " + DatabaseFileArchive.TABLE + " "
+                            + "group by " + DatabaseFileArchive.COLUMN_PROVIDER, null
+                )
+                while (cur.moveToNext()) {
+                    val c = SourceCount()
+                    c.source = cur.getString(0)
+                    c.rowCount = cur.getLong(1)
+                    c.sizeMin = cur.getLong(2)
+                    c.sizeMax = cur.getLong(3)
+                    c.sizeTotal = cur.getLong(4)
+                    c.sizeAvg = c.sizeTotal / c.rowCount
+                    ret.add(c)
+                }
+            } catch (e: Exception) {
+                catchException(e)
+            } finally {
+                cur?.close()
+            }
+            return ret
+        }
+    val rowCountExpired: Long
+        get() = getRowCount(
+            "$COLUMN_EXPIRES<?", arrayOf(System.currentTimeMillis().toString())
+        )
+
+    class SourceCount() {
+        var rowCount: Long = 0
+        var source: String? = null
+        var sizeTotal: Long = 0
+        var sizeMin: Long = 0
+        var sizeMax: Long = 0
+        var sizeAvg: Long = 0
+    }
+}
\ No newline at end of file