關於PG中Makefile裏的PGXS

If you are thinking about distributing your PostgreSQL extension modules, setting up a portable build system for them can be fairly difficult. 
Therefore the PostgreSQL installation provides a build infrastructure for extensions, called PGXS, 
so that simple extension modules can be built simply against an already installed server. 
PGXS is mainly intended for extensions that include C code, although it can be used for pure-SQL extensions too. 
Note that PGXS is not intended to be a universal build system framework that can be used to build any software interfacing to PostgreSQL; 
it simply automates common build rules for simple server extension modules. For more complicated packages, you might need to write your own build system
 

若是您正在考慮分發PostgreSQL擴展模塊，那麼爲它們設置可移植的構建系統可能至關困難。

所以，PostgreSQL安裝爲擴展提供了一個構建基礎設施，稱爲PGXS。

所以，簡單的擴展模塊能夠簡單地創建在已經安裝的服務器上。

PGXS主要用於包括C代碼的擴展，儘管它也能夠用於純SQL擴展。

請注意，PGXS並不打算是一個通用的構建系統框架，可用於構建任何與PostgreSQL接口的軟件；

它簡單地爲簡單的服務器擴展模塊自動化公共構建規則。對於更復雜的包，您可能須要編寫本身的構建系統。