From 42cb8a21c70ac09116f8a6f1a5c8ffe23cc11e18 Mon Sep 17 00:00:00 2001
From: "Peter J. Holzer" <hjp@hjp.at>
Date: Sat, 13 Apr 2019 23:44:19 +0200
Subject: [PATCH] Measure bloat by continuously updating a table

---
 update-bloat | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100755 update-bloat

diff --git a/update-bloat b/update-bloat
new file mode 100755
index 0000000..96a19bd
--- /dev/null
+++ b/update-bloat
@@ -0,0 +1,43 @@
+#!/usr/bin/python3
+
+import argparse
+import random
+import time
+
+import psycopg2
+
+ap = argparse.ArgumentParser()
+
+ap.add_argument("--dbname", default="")
+ap.add_argument("--rows", type=int, default=int(1E6))
+ap.add_argument("--updates-per-transaction", type=int, default=1)
+ap.add_argument("--transactions-per-sample", type=int, default=1)
+ap.add_argument("--sleep-between-transactions", type=float, default=1.0)
+args = ap.parse_args()
+
+db = psycopg2.connect("dbname='%s'" % (args.dbname, ))
+csr = db.cursor()
+csr.execute("drop table if exists tmp_update_bloat")
+csr.execute("create table tmp_update_bloat(id serial primary key, t text)")
+for i in range(args.rows):
+    t = "%s.%d" % ("a" * random.randrange(4, 64), i)
+    csr.execute("insert into tmp_update_bloat(t) values(%s)", (t,))
+db.commit()
+
+n_updates = 0
+n_transactions = 0
+while True:
+    csr.execute("select pg_total_relation_size('tmp_update_bloat')")
+    size = csr.fetchone()[0]
+    print(n_transactions, n_updates, size)
+    for i in range(args.transactions_per_sample):
+        for j in range(args.updates_per_transaction):
+            id = random.randrange(args.rows) + 1
+            t = "%s.%d" % ("b" * random.randrange(4, 64), n_updates)
+            csr.execute("update tmp_update_bloat set t = %s where id = %s", (t, id,))
+            n_updates += 1
+        db.commit()
+        n_transactions += 1
+        time.sleep(args.sleep_between_transactions)
+
+