diff --git a/is_primary.sh b/is_primary.sh
new file mode 100644
index 0000000..8d50f64
--- /dev/null
+++ b/is_primary.sh
@@ -0,0 +1,40 @@
+#
+# retourne true si la base est primaire
+# 
+
+#------------------------------------------------------------------------------
+# fonction d'aide
+#------------------------------------------------------------------------------
+f_help() {
+
+        cat <<CATEOF
+syntax : $O ORACLE_SID
+
+CATEOF
+exit $1
+
+} #f_help
+
+#------------------------------------------------------------------------------
+
+ORACLE_SID=$1
+
+[ "${ORACLE_SID}" ] || f_help 2;
+
+# positionner les variables d'environnement ORACLE
+export ORACLE_SID
+ORAENV_ASK=NO
+PATH=/usr/local/bin:$PATH
+. oraenv -s >/dev/null
+
+dbrole=$(sqlplus -s '/ as sysdba' << EOF
+    set pages 0 feedback off;
+    SELECT DATABASE_ROLE FROM V\$DATABASE;
+EOF
+
+if [ "$dbrole" == "PRIMARY" ]
+then
+    return true
+else
+    return false
+fi