Constant UPSERT_CHECKPOINT_BLOBS_SQL 

pub const UPSERT_CHECKPOINT_BLOBS_SQL: &str = r#"
INSERT INTO checkpoint_blobs (thread_id, checkpoint_ns, channel, version, type, blob)
VALUES ($1, $2, $3, $4, $5, $6)
ON CONFLICT (thread_id, checkpoint_ns, channel, version) DO NOTHING
"#;

Upsert checkpoint blobs.