sysdbql(7): Document typed expressions.

[sysdb.git] / doc / sysdbql.7.txt

diff --git a/doc/sysdbql.7.txt b/doc/sysdbql.7.txt
index 7ed9a11ec61baf7ad6b9db02b70b7d26465cb639..9a16e23a4593f58f7ca582728e4828b6d68205aa 100644 (file)
--- a/doc/sysdbql.7.txt
+++ b/doc/sysdbql.7.txt
@@ -177,6 +177,15 @@ The following fields may be queried:
        an attribute value with some other value, the two values will be cast to
        strings before comparing them.
 
        an attribute value with some other value, the two values will be cast to
        strings before comparing them.
 

+Field expressions may be applied to parent or child nodes. For example, a
+host's services are child objects and the host is the parent of the service
+objects. This is done using typed expressions:
+
+host|service|metric.'<field>'::
+       Evaluate the field in the context of the respective parent or child.
+       Currently, this is limited to services or metrics referencing their parent
+       host.
+

 The following logical operators are supported by SysDB. Unless otherwise
 noted, the data types of the left hand and right hand side have to match.
 
 The following logical operators are supported by SysDB. Unless otherwise
 noted, the data types of the left hand and right hand side have to match.
 


@@ -200,7 +209,7 @@ noted, the data types of the left hand and right hand side have to match.
        Checks whether a value compares less than, less than or equal to, greater
        than or equal, or greater than some other value.
 
        Checks whether a value compares less than, less than or equal to, greater
        than or equal, or greater than some other value.
 

-The following arithmetic operators are supported by SysDB. Unless otherwise 
+The following arithmetic operators are supported by SysDB. Unless otherwise

 noted, the data types of the left hand and right hand side have to match.
 
 *+*::
 noted, the data types of the left hand and right hand side have to match.
 
 *+*::