Added default-metrics privileges requirement

README.md

@@ -88,7 +88,6 @@ In order to run, you'll need the [Oracle Instant Client Basic](http://www.oracle
 for your operating system. Only the basic version is required for execution.
 
 # Running
-
 Ensure that the environment variable DATA_SOURCE_NAME is set correctly before starting.
 DATA_SOURCE_NAME should be in Oracle EZCONNECT format:  
  https://docs.oracle.com/en/database/oracle/oracle-database/19/netag/configuring-naming-methods.html#GUID-B0437826-43C1-49EC-A94D-B650B6A4A6EE  
@@ -110,6 +109,20 @@ export DATA_SOURCE_NAME=user/password@//primaryhost:1521,standbyhost:1521/+ASM?a
 # Then run the exporter
 /path/to/binary/oracledb_exporter --log.level error --web.listen-address 0.0.0.0:9161
 ```
+## Default-metrics requirement
+Make sure to grant `SYS` privilege on `SELECT` statement for the monitoring user, on the following tables.
+```
+dba_tablespace_usage_metrics
+dba_tablespaces
+v$system_wait_class
+v$asm_diskgroup_stat
+v$datafile
+v$sysstat
+v$process
+v$waitclassmetric
+v$session
+v$resource_limit
+```
 
 # Integration with System D
 
@@ -518,4 +531,4 @@ using the `--web.config` parameter. The format of the file is described
 [in the exporter-toolkit repository](https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md).
 
 Note that the TLS and basic authentication settings affect all HTTP endpoints:
-/metrics for scraping, /probe for probing, and the web UI.
+/metrics for scraping, /probe for probing, and the web UI.