PostGIS中的几乎所有函数都从ST开始。例如ST_Distance_Sphere，ST_GeomFromText，ST_Intersection等
ST是什么意思？
http://www.postgis.org/documentation/manual-svn/PostGIS_Special_Functions_Index.html
从
manual：
原文链接：https://www.f2er.com/postgresql/193320.htmlPostGIS has begun a transition from the existing naming convention to
an sql-MM-centric convention. As a result,most of the functions that
you know and love have been renamed using the standard spatial type
(ST) prefix. PrevIoUs functions are still available,though are not
listed in this document where updated functions are equivalent. These
will be deprecated in a future release.
希望有帮助。
