Keep Postgres thread cache setting test-scoped

Author: bill-ph

src/metadata_manager/postgres_metadata_manager.cpp

@@ -329,10 +329,8 @@ SELECT EXISTS (
 	if (result->HasError()) {
 		return false;
 	}
-	for (auto &row : *result) {
-		return row.GetValue<bool>(0);
-	}
-	return false;
+	auto chunk = result->Fetch();
+	return chunk && chunk->size() > 0 && chunk->GetValue(0, 0).GetValue<bool>();
 }
 
 // We need a specialized function here to do a reinterpret for postgres from BLOB to VARCHAR

src/storage/ducklake_initializer.cpp

@@ -64,9 +64,6 @@ void DuckLakeInitializer::Initialize() {
 		error_obj.Throw("Failed to attach DuckLake MetaData \"" + catalog.MetadataDatabaseName() + "\" at path + \"" +
 		                catalog.MetadataPath() + "\"");
 	}
-	if (catalog.MetadataType() == "postgres" || catalog.MetadataType() == "postgres_scanner") {
-		transaction.Query("SET pg_connection_cache=false");
-	}
 	// explicitly load all secrets - work-around to secret initialization bug
 	transaction.Query("FROM duckdb_secrets()");
 

test/configs/postgres.json

@@ -1,6 +1,6 @@
 {
   "description": "Run DuckLake tests using Postgres as a catalog DBMS.",
-  "on_init": "ATTACH 'dbname=ducklakedb' AS pg (TYPE postgres); USE pg; DROP SCHEMA public CASCADE; DROP SCHEMA IF EXISTS metadata_s1 CASCADE; DROP SCHEMA IF EXISTS metadata_s2 CASCADE; CREATE SCHEMA public;USE memory; DETACH pg;",
+  "on_init": "LOAD postgres_scanner; SET GLOBAL pg_pool_enable_thread_local_cache=false; ATTACH 'dbname=ducklakedb' AS pg (TYPE postgres); USE pg; DROP SCHEMA public CASCADE; DROP SCHEMA IF EXISTS metadata_s1 CASCADE; DROP SCHEMA IF EXISTS metadata_s2 CASCADE; CREATE SCHEMA public;USE memory; DETACH pg;",
   "autoloading": "none",
   "statically_loaded_extensions": [
     "core_functions",