Fix case insensitivity issues

include/pgduckdb/catalog/pgduckdb_transaction.hpp

@@ -2,6 +2,7 @@
 
 #include "duckdb/main/client_context.hpp"
 #include "duckdb/main/client_context_state.hpp"
+#include "duckdb/common/unordered_map.hpp"
 #include "duckdb/transaction/transaction.hpp"
 #include "pgduckdb/pg/declarations.hpp"
 
@@ -26,12 +27,12 @@ class SchemaItems {
 private:
 	duckdb::string name;
 	duckdb::unique_ptr<PostgresSchema> schema;
-	duckdb::case_insensitive_map_t<duckdb::unique_ptr<PostgresTable>> tables;
+	duckdb::unordered_map<duckdb::string, duckdb::unique_ptr<PostgresTable>> tables;
 };
 
 class PostgresContextState : public duckdb::ClientContextState {
 public:
-	duckdb::case_insensitive_map_t<SchemaItems> schemas;
+	duckdb::unordered_map<duckdb::string, SchemaItems> schemas;
 	void QueryEnd() override;
 };
 

test/regression/expected/case_insensitivity.out

@@ -0,0 +1,23 @@
+CREATE TABLE a(b int);
+CREATE TABLE "A"(c int);
+INSERT INTO a VALUES(1);
+SELECT * FROM a, "A" as aa;
+ b | c 
+---+---
+(0 rows)
+
+CREATE SCHEMA b;
+CREATE SCHEMA "B";
+CREATE TABLE b.a(d int);
+CREATE TABLE "B".a(e int);
+INSERT INTO b.a VALUES(1);
+SELECT * FROM b.a, "B".a as aa;
+ d | e 
+---+---
+(0 rows)
+
+DROP TABLE a, "A";
+DROP SCHEMA CASCADE b, "B";
+ERROR:  syntax error at or near "b"
+LINE 1: DROP SCHEMA CASCADE b, "B";
+                            ^

test/regression/sql/case_insensitivity.sql

@@ -0,0 +1,34 @@
+CREATE TABLE a(b int);
+CREATE TABLE "A"(c int);
+INSERT INTO a VALUES(1);
+INSERT INTO "A" VALUES(2);
+
+-- BUG: This fails because DuckDB considers the aliasses "a" and "A" to be
+-- equivalent. This is something that can probably be fixed most easily in
+-- DuckDB by having a mode in which aliases are case-sensitive.
+SELECT * FROM a, "A";
+-- Luckily there's an easy workaround for that
+SELECT * FROM a, "A" as a2;
+
+CREATE SCHEMA b;
+CREATE SCHEMA "B";
+
+CREATE TABLE b.a(d int);
+CREATE TABLE "B".a(e int);
+
+INSERT INTO b.a VALUES(3);
+INSERT INTO "B".a VALUES(4);
+
+-- This actually succeeds, in contrast to the similar query above. because the
+-- tables have the same casing in Postgres too, so Postgres will give them
+-- unique automatic aliases.
+SELECT * FROM b.a, "B".a;
+-- We can make it fail in the same way with an explicit alias though.
+SELECT * FROM b.a, "B".a as "A";
+-- With different explicit aliases it should obviously succeed too..
+SELECT * FROM b.a, "B".a as a2;
+
+set client_min_messages TO WARNING;
+DROP TABLE a, "A";
+DROP SCHEMA b, "B" CASCADE;
+