diff --git a/build_database.py b/build_database.py
index 4136be5..8eb933f 100644
--- a/build_database.py
+++ b/build_database.py
@@ -196,6 +196,9 @@ async def main_with_ctx(ctx, wanted_date):
             await ctx.db.commit()
 
     log.info("going to process posts")
+    post_count_rows = await ctx.db.execute_fetchall("select count(*) from posts")
+    post_count = post_count_rows[0][0]
+    log.info("already have %d posts", post_count)
 
     with output_uncompressed_paths["posts"].open(
         mode="r", encoding="utf-8"
@@ -207,80 +210,87 @@ async def main_with_ctx(ctx, wanted_date):
         line_count -= 1  # remove header
 
         log.info("%d posts to import", line_count)
-        posts_csv_fd.seek(0)
-        posts_reader = csv.DictReader(posts_csv_fd)
+        if line_count == post_count:
+            log.info("already imported everything, skipping")
+        else:
+            posts_csv_fd.seek(0)
+            posts_reader = csv.DictReader(posts_csv_fd)
 
-        processed_count = 0
-        processed_ratio = 0.0
+            processed_count = 0
+            processed_ratio = 0.0
 
-        for row in posts_reader:
-            created_at_str = row["created_at"]
-            created_at = datetime.strptime(
-                created_at_str[: created_at_str.find(".")], "%Y-%m-%d %H:%M:%S"
-            )
+            for row in posts_reader:
+                created_at_str = row["created_at"]
+                created_at = datetime.strptime(
+                    created_at_str[: created_at_str.find(".")], "%Y-%m-%d %H:%M:%S"
+                )
 
-            post = Post(
-                id=int(row["id"]),
-                uploader_id=int(row["uploader_id"]),
-                created_at=int(created_at.timestamp()),
-                md5=row["md5"],
-                source=row["source"],
-                rating=row["rating"],
-                tag_string=row["tag_string"],
-                is_deleted=e621_bool(row["is_deleted"]),
-                is_pending=e621_bool(row["is_pending"]),
-                is_flagged=e621_bool(row["is_flagged"]),
-                score=int(row["score"]),
-                up_score=int(row["up_score"]),
-                down_score=int(row["down_score"]),
-                is_rating_locked=e621_bool(row["is_rating_locked"]),
-            )
+                post = Post(
+                    id=int(row["id"]),
+                    uploader_id=int(row["uploader_id"]),
+                    created_at=int(created_at.timestamp()),
+                    md5=row["md5"],
+                    source=row["source"],
+                    rating=row["rating"],
+                    tag_string=row["tag_string"],
+                    is_deleted=e621_bool(row["is_deleted"]),
+                    is_pending=e621_bool(row["is_pending"]),
+                    is_flagged=e621_bool(row["is_flagged"]),
+                    score=int(row["score"]),
+                    up_score=int(row["up_score"]),
+                    down_score=int(row["down_score"]),
+                    is_rating_locked=e621_bool(row["is_rating_locked"]),
+                )
 
-            await ctx.db.execute(
-                """
-                insert into posts (
-                    id,
-                    uploader_id,
-                    created_at,
-                    md5,
-                    source,
-                    rating,
-                    tag_string,
-                    is_deleted,
-                    is_pending,
-                    is_flagged,
-                    score,
-                    up_score,
-                    down_score,
-                    is_rating_locked
-                ) values (?,?,?,?,?,?,?,?,?,?,?,?,?,?)
-                """,
-                (
-                    post.id,
-                    post.uploader_id,
-                    post.created_at,
-                    post.md5,
-                    post.source,
-                    post.rating,
-                    post.tag_string,
-                    post.is_deleted,
-                    post.is_pending,
-                    post.is_flagged,
-                    post.score,
-                    post.up_score,
-                    post.down_score,
-                    post.is_rating_locked,
-                ),
-            )
-            processed_count += 1
-            new_processed_ratio = round((processed_count / line_count) * 100, 2)
-            if str(new_processed_ratio) != str(processed_ratio):
-                log.info("posts processed at %.2f%%", processed_ratio)
-                processed_ratio = new_processed_ratio
+                await ctx.db.execute(
+                    """
+                    insert into posts (
+                        id,
+                        uploader_id,
+                        created_at,
+                        md5,
+                        source,
+                        rating,
+                        tag_string,
+                        is_deleted,
+                        is_pending,
+                        is_flagged,
+                        score,
+                        up_score,
+                        down_score,
+                        is_rating_locked
+                    ) values (?,?,?,?,?,?,?,?,?,?,?,?,?,?)
+                    """,
+                    (
+                        post.id,
+                        post.uploader_id,
+                        post.created_at,
+                        post.md5,
+                        post.source,
+                        post.rating,
+                        post.tag_string,
+                        post.is_deleted,
+                        post.is_pending,
+                        post.is_flagged,
+                        post.score,
+                        post.up_score,
+                        post.down_score,
+                        post.is_rating_locked,
+                    ),
+                )
+                processed_count += 1
+                new_processed_ratio = round((processed_count / line_count) * 100, 2)
+                if str(new_processed_ratio) != str(processed_ratio):
+                    log.info("posts processed at %.2f%%", processed_ratio)
+                    processed_ratio = new_processed_ratio
 
-        log.info("posts done")
+            log.info("posts done")
 
-        await ctx.db.commit()
+            await ctx.db.commit()
+
+    log.info("vacuuming db...")
+    await ctx.db.execute("vacuum")
+    log.info("database built")
 
 
 async def main():