Report how many changes were done in the interface

README.md

@@ -109,6 +109,9 @@ variables](https://www.postgresql.org/docs/current/libpq-envars.html), such as
   (`CREATE`, `MERGE`, `SET`, `DELETE`, `REMOVE`, or `CALL` of a procedure) run to
   completion first and are buffered, because AGE performs writes while their rows are
   fetched.
+- **Write statistics** come from PostgreSQL's per-transaction table statistics, read
+  before and after each query that can write, so such a query runs in a transaction
+  of its own.
 - **Neo4j procedures** that neo4j-browser relies on (`dbms.components`, `SHOW DATABASES`,
   `db.labels`, `db.schema.visualization`, `SHOW PROCEDURES`, ...) are emulated from the
   AGE catalog.
@@ -519,8 +522,10 @@ addressing it in [`plans/`](plans/README.md):
 
 1. `RETURN *`, `EXPLAIN` and `PROFILE`
    ([plan](plans/01-return-star-explain-profile.md)).
-2. Write statistics: write queries report "(no changes, no records)" even when they
-   changed the graph ([plan](plans/02-write-statistics.md)).
+2. Write statistics are only approximate for properties: `properties-set` counts the
+   nodes and relationships changed by `SET` and `REMOVE`, not their properties, and
+   leaves out the properties of `CREATE` and `MERGE`
+   ([plan](plans/02-write-statistics.md)).
 3. Anything AGE does not support, for example multiple labels per node, pattern
    comprehensions, temporal and spatial types, indexes and constraints through Cypher
    ([plan](plans/03-age-unsupported-features.md)).