Github user traflm commented on a diff in the pull request:
https://github.com/apache/trafodion/pull/1698#discussion_r212510010
--- Diff:
docs/sql_reference/src/asciidoc/_chapters/sql_functions_and_expressions.adoc ---
@@ -11290,6 +11295,99 @@ ID
--- 1 row(s) selected.
```
+<<<
+[[uuid_function]]
+== UUID Function
+Returns a Universal Unique Identifier (UUID) generated according to RFC
4122.
+A UUID is designed as a number that is globally unique in space and time.
+Two calls to UUID() are expected to generate two different values, even if
+these calls are performed on two separate devices not connected to each
other.
+
+NOTE: But UUID() can only be used in SELECT list, or very simple
expressions to get a UUID.
--- End diff --
We don't prevent it from being used in the WHERE clause. It can be used in
some special case. It just we don't know where optimizer will choose to
evaluate this function. If in ROOT, it will be one value for per statement, if
it pushdown to SCAN, it will be one value for each row.
So I will update the words as you suggested.
---
