From 7d75d423e43ada8ce28b83ea8721be8e570fe7ed Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Tue, 9 Jan 2024 13:27:27 -0800
Subject: [PATCH] Added section on index build time [skip ci]

---
 README.md | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/README.md b/README.md
index 5d0efc0..093bf79 100644
--- a/README.md
+++ b/README.md
@@ -190,6 +190,22 @@ CREATE INDEX ON items USING hnsw (embedding vector_cosine_ops);
 
 Vectors with up to 2,000 dimensions can be indexed.
 
+### Index Build Time
+
+Indexes build significantly faster when the graph fits into `maintenance_work_mem`
+
+```sql
+SET maintenance_work_mem = '8GB';
+```
+
+A notice is shown when the graph no longer fits
+
+```text
+NOTICE:  hnsw graph no longer fits into maintenance_work_mem after 100000 tuples
+DETAIL:  Building will take significantly more time.
+HINT:  Increase maintenance_work_mem to speed up builds.
+```
+
 ### Index Options
 
 Specify HNSW parameters