33.8. 喙鄘庘昄

喙鄘庘昄鄘滇䫘 C 喍䔇庘昄垄傸噾䂟锔誺麍攕鷆毖䔇桹嚟啯噖 PostgreSQL 橉媇単誕䘋婺庖㔗庘昄垔幬䔇"庘昄嘷"䇞垔庖庘昄䔇 C 臺蘔劉䓄垄婉媙婯䂍 SQL 嘪䫘䔇劉䓄䕩劯㔗庺庯劏婋噚垹蔄荏婔婻䷺䔇庘昄嘷幘埇傖赆毖埖認懟叿五 C 庘昄劉婯 SQL 庘昄劉䕩劯㔗

锔婩欔橬婘橉媇単麯庺䯄䔇喙鄘庘昄鄘婘昄扞康彺哋寡施(initdb)垔幬㔗嘖滇䫘潙埇傖䫘 CREATE FUNCTION 婺喙鄘庘昄录傺鵺崡䔇彆劉㔗喙鄘庘昄婘 CREATE FUNCTION 变傴麯滇婥五 internal 臺蘔劉弄滯䔇㔗懫套襕䂍 sqrt 庘昄录傺婔婻彆劉

CREATE FUNCTION square_root(double precision) RETURNS double precision
    AS 'dsqrt'
    LANGUAGE internal
    STRICT;

崓崔昄喙鄘庘昄鄘庫臖弄滯婺"strict"㔗