Smaller batch size.

lib/zxystream.js

@@ -9,7 +9,7 @@ util.inherits(ZXYStream, stream.Readable);
 //
 // The `batch` option exists to allow tests to check that
 // multiple calls to `_read` are handled properly. IRL the
-// default offset of 10000 should be reasonably efficient
+// default offset of 1000 should be reasonably efficient
 // and not worth messing with.
 function ZXYStream(source, options) {
     if (!source) throw new TypeError('MBTiles source required');
@@ -20,7 +20,7 @@ function ZXYStream(source, options) {
         throw new TypeError('options.batch must be a positive integer');
 
     this.source = source;
-    this.batch = options.batch || 10000;
+    this.batch = options.batch || 1000;
     this.offset = 0;
 
     stream.Readable.call(this);