diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml index 0a4379a76b..75a0e3edd5 100644 --- a/doc/src/sgml/libpq.sgml +++ b/doc/src/sgml/libpq.sgml @@ -1,4 +1,4 @@ - + <application>libpq</application> - C Library @@ -63,6 +63,21 @@ The PQstatus function should be called to check whether a connection was successfully made before queries are sent via the connection object. + + + + On Windows, there is a way to improve performance if a single + database connection is repeated started and shutdown. Internally, + libpq calls WSAStartup() and WSACleanup() for connection startup + and shutdown, respectively. WSAStartup() increments an internal + Windows library reference count which is decremented by WSACleanup(). + When the reference count is just one, calling WSACleanup() frees + all resources and all DLLs are unloaded. This is an expensive + operation. To avoid this, an application can manually call + WSAStartup() so resources will not be freed when the last database + connection is closed. + +