From: Peter Geoghegan <pg@heroku.com>
Date: Fri, 14 Mar 2014 06:34:31 +0000 (-0700)
Subject: Remarks on GIN numeric textual storage
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=e678abfd6bb6540fb721a76844bfee0fc05deb98;p=users%2Fandresfreund%2Fpostgres.git

Remarks on GIN numeric textual storage
---

diff --git a/src/backend/utils/adt/jsonb_gin.c b/src/backend/utils/adt/jsonb_gin.c
index bac94739a1..8fddd581c9 100644
--- a/src/backend/utils/adt/jsonb_gin.c
+++ b/src/backend/utils/adt/jsonb_gin.c
@@ -425,6 +425,11 @@ make_scalar_text_key(const JsonbValue * v, char flag)
 			/*
 			 * A normalized textual representation, free of trailing zeroes is
 			 * is required.
+			 *
+			 * It isn't ideal that numerics are stored in a relatively bulky
+			 * textual format.  However, it's a notationally convenient way of
+			 * storing a "union" type in the GIN B-Tree, and indexing Jsonb
+			 * strings take precedence.
 			 */
 			cstr = numeric_normalize(v->numeric);
 			item = make_text_key(cstr, strlen(cstr), flag);
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 92e3528c8f..a4d5b0369f 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -652,14 +652,14 @@ numeric_normalize(Numeric num)
 
 	for (;;)
 	{
-		if (str[last] != '0')
+		if (last == 0 || str[last] != '0')
 			break;
 
 		str[last] = '\0';
 		last--;
 	}
 
-	if (str[last] == '.')
+	if (last != 0 && str[last] == '.')
 		str[last] = '\0';
 
 	return str;