chore: add duckdb example to arrow-pg

Author: sunng87

Cargo.lock

@@ -16,13 +16,26 @@ rust-version.workspace = true
 default = ["arrow"]
 arrow = ["dep:arrow"]
 datafusion = ["dep:datafusion"]
+# for testing
+_duckdb = []
+_bundled = ["duckdb/bundled"]
+
 
 [dependencies]
 arrow = { workspace = true, optional = true }
 bytes.workspace = true
 chrono.workspace = true
 datafusion = { workspace = true, optional = true }
 futures.workspace = true
-pgwire = { version = ">=0.32, <0.33", default-features = false, features = ["server-api"] }
+pgwire = { workspace = true, default-features = false, features = ["server-api"] }
 postgres-types.workspace = true
 rust_decimal.workspace = true
+
+[dev-dependencies]
+async-trait = "0.1"
+duckdb = { version = "~1.4" }
+tokio = { version = "1.19", features = ["full"]}
+
+[[example]]
+name = "duckdb"
+required-features = ["_duckdb"]