bug fix

README.md

@@ -54,10 +54,10 @@ AQuery++ Database is a cross-platform, In-Memory Column-Store Database that inco
   
 # Installation
 ## Requirements
-1. Recent version of Linux, Windows or MacOS, with recent C++ compiler that has C++17 (1z) support.
-     - GCC: 9.0 or above (g++ 7.x, 8.x fail to handle variadic template expansion due to a compiler bug)
+1. Recent version of Linux, Windows or MacOS, with recent C++ compiler that has C++17 (1z) support. (however c++20 is recommended if available for heterogeneous lookup on unordered containers)
+     - GCC: 9.0 or above (g++ 7.x, 8.x fail to handle fold-expressions due to a compiler bug)
      - Clang: 5.0 or above (Recommended)
-     - MSVC: 2017 or later
+     - MSVC: 2017 or later (2022 or above is recommended)
 
 2. Monetdb for Hybrid Engine
    - On windows, the required libraries and headers are already included in the repo.

aquery_config.py

@@ -10,7 +10,7 @@ have_hge = False
 cygroot = 'c:/msys64/usr/bin'
 msbuildroot = ''
 os_platform = 'unknown'
-build_driver = 'MSBuild'
+build_driver = 'Makefile'
 
 def init_config():
     global __config_initialized__, os_platform, msbuildroot

server/pch.hpp

@@ -16,6 +16,7 @@
 #include <fcntl.h>
 #include <sys/mman.h>
 #endif
+#endif
 
 #undef max
 #undef min