From 535865a3dc6da7cec83eed308ce4c4af1b835b7a Mon Sep 17 00:00:00 2001
From: Austin Barrington <austin@hyperbyte.dev>
Date: Sat, 17 Oct 2026 13:53:27 +0100
Subject: [PATCH] Gate the fallback stream counter on not(direct_arrow_insert)

With an engine that inserts Arrow arrays directly (libchdb 26.9.0),
FALLBACK_STREAM_SEQ and its Ordering import were unused, and a build
with RUSTFLAGS=-D warnings failed on them. hyperbytedb's CI builds this
crate that way against the latest engine, so its Clippy job failed.
---
 src/arrow_insert.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/arrow_insert.rs b/src/arrow_insert.rs
index bf277c9..8d4fdd4 100644
--- a/src/arrow_insert.rs
+++ b/src/arrow_insert.rs
@@ -4,6 +4,7 @@
 //! [`Connection::register_arrow_array`](crate::connection::Connection::register_arrow_array),
 //! and `INSERT INTO … SELECT * FROM ArrowStream('name')`.
 
+#[cfg(not(direct_arrow_insert))]
 use std::sync::atomic::{AtomicU64, Ordering};
 
 use arrow::array::RecordBatchReader;
@@ -18,6 +19,10 @@ use crate::connection::Connection;
 use crate::error::Result;
 use crate::format::OutputFormat;
 
+/// Names the registered stream when the engine cannot insert an Arrow array
+/// directly. Built only then: with `direct_arrow_insert` it was unused, and a
+/// `-D warnings` build against such an engine failed.
+#[cfg(not(direct_arrow_insert))]
 static FALLBACK_STREAM_SEQ: AtomicU64 = AtomicU64::new(0);
 
 /// Owns Arrow C Data Interface structs for the lifetime of a registration or insert.