From 1ef7ba20e774bd8f94a9642db22585c5b9aa3aa7 Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Wed, 19 Mar 2003 21:20:52 +0000 Subject: [PATCH] Remove typecasting section that isn't needed anymore. --- doc/src/sgml/typeconv.sgml | 53 +------------------------------------- 1 file changed, 1 insertion(+), 52 deletions(-) diff --git a/doc/src/sgml/typeconv.sgml b/doc/src/sgml/typeconv.sgml index d049451e68..f17e2e5c9a 100644 --- a/doc/src/sgml/typeconv.sgml +++ b/doc/src/sgml/typeconv.sgml @@ -1,5 +1,5 @@ @@ -403,57 +403,6 @@ type to resolve the unknown literals to. - -Absolute-Value and Factorial Operator Type Resolution - - -The PostgreSQL operator catalog has several -entries for the prefix operator @, all of which implement -absolute-value operations for various numeric data types. One of these -entries is for type float8, which is the preferred type in -the numeric category. Therefore, PostgreSQL -will use that entry when faced with a non-numeric input: - -SELECT @ '-4.5' AS "abs"; - abs ------ - 4.5 -(1 row) - -Here the system has performed an implicit conversion from text to float8 -before applying the chosen operator. We can verify that float8 and -not some other type was used: - -SELECT @ '-4.5e500' AS "abs"; - -ERROR: Input '-4.5e500' is out of range for float8 - - - - -On the other hand, the postfix operator ! (factorial) -is defined only for integer data types, not for float8. So, if we -try a similar case with !, we get: - -SELECT '20' ! AS "factorial"; - -ERROR: Unable to identify a postfix operator '!' for type 'text' - You may need to add parentheses or an explicit cast - -This happens because the system can't decide which of the several -possible ! operators should be preferred. We can help -it out with an explicit cast: - -SELECT CAST('20' AS int8) ! AS "factorial"; - - factorial ---------------------- - 2432902008176640000 -(1 row) - - - -