yet another try to get the rpn example right ... #246

[rrdtool.git] / doc / rrdgraph_libdbi.pod

diff --git a/doc/rrdgraph_libdbi.pod b/doc/rrdgraph_libdbi.pod
index 6ff8728..c84465d 100644 (file)
--- a/doc/rrdgraph_libdbi.pod
+++ b/doc/rrdgraph_libdbi.pod
@@ -41,9 +41,10 @@ This pseudo-rrd-filename defines a sql datasource:
 
   hex-type-encoding via %xx are translated to the actual value, use %% to use %
 
-=item B<E<lt>unixtimestamp columnE<gt>>
+=item B<E<lt>[*]unixtimestamp columnE<gt>>
 
-  defines the column of E<lt>tableE<gt> which contains the unix timestamp
+  defines the column of E<lt>tableE<gt> which contains the unix-timestamp 
+  - if this is a DATETIME field in the database, then prefix with leading '*'
 
   hex-type-encoding via %xx are translated to the actual value, use %% to use %
 
@@ -79,7 +80,7 @@ the returned value column-names, which can be used as ds-names, are:
 
 =head1 EXAMPLES
 
-Here an example of a table in a mysql database:
+Here an example of a table in a MySQL database:
 
   DB connect information
     dbhost=127.0.0.1
@@ -118,13 +119,13 @@ To illustrate this here a command to create a graph that contains the actual val
 
 =head1 NOTES
 
-* Naturally you can also use any other kind of driver that libdbi supports - e.g postgress,...
+* Naturally you can also use any other kind of driver that libdbi supports - e.g postgres, ...
 
-* From the way the datasource is joined, it should also be possible to do joins over different tables 
+* From the way the data source is joined, it should also be possible to do joins over different tables 
   (separate tables with "," in table and add in the WHERE Clauses the table equal joins. 
   This has not been tested!!!)
 
-* It should also be relatively simple to add to the database using the same datasource string.
+* It should also be relatively simple to add to the database using the same data source string.
   This has not been implemented...
 
 * The aggregation functions are ignored and several data columns are used instead 
@@ -145,6 +146,13 @@ To illustrate this here a command to create a graph that contains the actual val
   (this only happens when the libdbi driver is actually used the first time!)
   This is KNOWN to be the case with RHEL4 and FC4 and FC5! (But actually this is a bug with libdbi make files!)
 
+* at least version 0.8.1 of libdbiexhibits a bug with BINARY fields
+  (shorttext,text,mediumtext,longtext and possibly also BINARY and BLOB fields), 
+  that can result in coredumps of rrdtool. 
+  The tool will tell you on stderr if this occures, so that you know what may be the reason.
+  If you are not experiencing these coredumps, then set the environment variable RRD_NO_LIBDBI_BUG_WARNING, 
+  and then the message will not get shown.
+
 =head1 AUTHOR
 
 Martin Sperl <rrdtool@martin.sperl.org>