diff --git a/build_database.py b/build_database.py
index 0dc06b6..c724fe6 100644
--- a/build_database.py
+++ b/build_database.py
@@ -1,4 +1,5 @@
 import asyncio
+import gzip
 import logging
 import shutil
 import tempfile
@@ -56,6 +57,8 @@ async def main():
                             log.info("download at %d%%", download_ratio)
                             download_ratio = new_download_ratio
 
+                    temp_fd.seek(0)
+
                     # write to output
                     log.info("copying temp to output")
                     with output_path.open(mode="wb") as output_fd:
@@ -69,7 +72,10 @@ async def main():
             original_name, original_extension, _gz = parsed_path.name.split(".")
             output_path = Path.cwd() / f"{original_name}.{original_extension}"
             if output_path.exists():
+                log.info("decompressed file %s already exists, ignoring", output_path)
                 continue
+
+            log.info("decompressing %s into %s", input_path.name, output_path.name)
             with gzip.open(input_path, "rb") as in_fd:
                 with output_path.open(mode="wb") as out_fd:
                     shutil.copyfileobj(in_fd, out_fd)