Match heap tables with fully qualified name

Makefile

@@ -19,7 +19,7 @@ SRCS = src/utility/copy.cpp \
 
 OBJS = $(subst .cpp,.o, $(SRCS))
 
-REGRESS = basic
+REGRESS = $(subst .sql,,$(subst sql/,,$(wildcard sql/*.sql)))
 
 PG_CONFIG ?= pg_config
 

expected/basic.out

@@ -48,3 +48,4 @@ DEBUG:  -- (DuckDB/PostgresHeapScanGlobalState) Running 4 threads --
 SET quack.max_threads_per_query TO default;
 SET client_min_messages TO default;
 DROP TABLE t;
+DROP EXTENSION quack;

expected/search_path.out

@@ -0,0 +1,71 @@
+CREATE EXTENSION quack;
+CREATE TABLE t(a INT);
+INSERT INTO t SELECT g from generate_series(1,10) g;
+SELECT count(*) FROM t;
+ count_star() 
+--------------
+           10
+(1 row)
+
+SELECT count(*) FROM public.t;
+ count_star() 
+--------------
+           10
+(1 row)
+
+-- Create schema `other`
+CREATE SCHEMA other;
+CREATE TABLE other.t(a INT);
+INSERT INTO other.t SELECT g from generate_series(1,100) g;
+SELECT count(*) FROM other.t;
+ count_star() 
+--------------
+          100
+(1 row)
+
+-- Test fully qualified table name combinations
+SELECT count(*) FROM public.t, other.t;
+ count_star() 
+--------------
+         1000
+(1 row)
+
+SELECT count(*) FROM t, other.t;
+ count_star() 
+--------------
+         1000
+(1 row)
+
+SELECT count(*) FROM t,t;
+ERROR:  table name "t" specified more than once
+-- search_path ORDER matters.
+SET search_path TO other, public;
+SELECT count(*) FROM t;
+ count_star() 
+--------------
+          100
+(1 row)
+
+SELECT count(*) FROM t, public.t;
+ count_star() 
+--------------
+         1000
+(1 row)
+
+-- No search_path
+SET search_path TO '';
+SELECT count(*) FROM t, other.t;
+ERROR:  relation "t" does not exist
+LINE 1: SELECT count(*) FROM t, other.t;
+                             ^
+SELECT count(*) FROM public.t, other.t;
+ count_star() 
+--------------
+         1000
+(1 row)
+
+-- Cleanup
+DROP TABLE other.t;
+DROP SCHEMA other;
+RESET search_path;
+DROP EXTENSION quack;

sql/basic.sql

@@ -17,4 +17,6 @@ SELECT a, COUNT(*) FROM t WHERE a > 5 GROUP BY a ORDER BY a;
 SET quack.max_threads_per_query TO default;
 SET client_min_messages TO default;
 
-DROP TABLE t;
+DROP TABLE t;
+
+DROP EXTENSION quack;

sql/search_path.sql

@@ -0,0 +1,34 @@
+CREATE EXTENSION quack;
+
+CREATE TABLE t(a INT);
+INSERT INTO t SELECT g from generate_series(1,10) g;
+SELECT count(*) FROM t;
+SELECT count(*) FROM public.t;
+
+-- Create schema `other`
+CREATE SCHEMA other;
+CREATE TABLE other.t(a INT);
+INSERT INTO other.t SELECT g from generate_series(1,100) g;
+SELECT count(*) FROM other.t;
+
+-- Test fully qualified table name combinations
+SELECT count(*) FROM public.t, other.t;
+SELECT count(*) FROM t, other.t;
+SELECT count(*) FROM t,t;
+
+-- search_path ORDER matters.
+SET search_path TO other, public;
+SELECT count(*) FROM t;
+SELECT count(*) FROM t, public.t;
+
+-- No search_path
+SET search_path TO '';
+SELECT count(*) FROM t, other.t;
+SELECT count(*) FROM public.t, other.t;
+
+-- Cleanup
+DROP TABLE other.t;
+DROP SCHEMA other;
+RESET search_path;
+
+DROP EXTENSION quack;

src/quack_heap_scan.cpp

@@ -5,8 +5,15 @@
 #include "duckdb/parser/expression/constant_expression.hpp"
 #include "duckdb/parser/expression/comparison_expression.hpp"
 #include "duckdb/parser/expression/columnref_expression.hpp"
+#include "duckdb/parser/qualified_name.hpp"
 #include "duckdb/common/enums/expression_type.hpp"
 
+extern "C" {
+#include "postgres.h"
+#include "catalog/namespace.h"
+#include "utils/regproc.h"
+}
+
 #include "quack/quack_heap_scan.hpp"
 #include "quack/quack_types.hpp"
 
@@ -139,6 +146,7 @@ PostgresHeapScanFunction::PostgresHeapScanFunc(duckdb::ClientContext &context, d
 static RangeTblEntry *
 FindMatchingHeapRelation(List *tables, const duckdb::string &to_find) {
 	ListCell *lc;
+
 	foreach (lc, tables) {
 		RangeTblEntry *table = (RangeTblEntry *)lfirst(lc);
 		if (table->relid) {
@@ -147,22 +155,22 @@ FindMatchingHeapRelation(List *tables, const duckdb::string &to_find) {
 				elog(ERROR, "Relation with OID %u is not valid", table->relid);
 				return nullptr;
 			}
-			char *rel_name = RelationGetRelationName(rel);
-			auto table_name = std::string(rel_name);
-			if (duckdb::StringUtil::CIEquals(table_name, to_find)) {
-				/* Allow only heap tables */
-				if (!rel->rd_amhandler || (GetTableAmRoutine(rel->rd_amhandler) != GetHeapamTableAmRoutine())) {
-					/* This doesn't have an access method handler, we cant read from this */
-					RelationClose(rel);
-					return nullptr;
-				} else {
-					RelationClose(rel);
-					return table;
-				}
+			/* Allow only heap tables */
+			if (!rel->rd_amhandler || (GetTableAmRoutine(rel->rd_amhandler) != GetHeapamTableAmRoutine())) {
+				/* This doesn't have an access method handler, we cant read from this */
+				RelationClose(rel);
+				return nullptr;
+			}
+			RangeVar *tableRangeVar = makeRangeVarFromNameList(stringToQualifiedNameList(to_find.c_str(), NULL));
+			Oid relOid = RangeVarGetRelid(tableRangeVar, AccessShareLock, true);
+			if (table->relid == relOid) {
+				RelationClose(rel);
+				return table;
 			}
 			RelationClose(rel);
 		}
 	}
+
 	return nullptr;
 }
 
@@ -196,6 +204,7 @@ PostgresHeapReplacementScan(duckdb::ClientContext &context, const duckdb::string
 	auto children = CreateFunctionArguments(table, GetActiveSnapshot());
 	auto table_function = duckdb::make_uniq<duckdb::TableFunctionRef>();
 	table_function->function = duckdb::make_uniq<duckdb::FunctionExpression>("postgres_heap_scan", std::move(children));
+	table_function->alias = table->alias ? table->alias->aliasname : table_name;
 
 	return std::move(table_function);
 }