fix(jdbc): fall back to jdbc schemas without all_users

plugins/jdbc/src/main/java/app/dbx/jdbc/DbxJdbcPlugin.java

@@ -3389,6 +3389,7 @@ public final class DbxJdbcPlugin {
                     return rs.getString(1);
                 }
             }
+        } catch (SQLException ignored) {
         }
         return null;
     }
@@ -3402,6 +3403,7 @@ public final class DbxJdbcPlugin {
                     return rs.getString(1);
                 }
             }
+        } catch (SQLException ignored) {
         }
         return null;
     }
@@ -3416,8 +3418,18 @@ public final class DbxJdbcPlugin {
                     result.add(name);
                 }
             }
+            return result;
+        } catch (SQLException e) {
+            try (ResultSet rs = conn.getMetaData().getSchemas()) {
+                while (rs.next()) {
+                    String schema = rs.getString("TABLE_SCHEM");
+                    if (schema != null && !schema.isBlank()) {
+                        result.add(schema);
+                    }
+                }
+            }
+            return result;
         }
-        return result;
     }
 
     private static JsonNode oracleListTables(Connection conn, String owner) throws SQLException {

plugins/jdbc/src/test/java/app/dbx/jdbc/DbxJdbcPluginTest.java

@@ -2730,6 +2730,28 @@ final class DbxJdbcPluginTest {
         }
     }
 
+    @Test
+    void oracleListSchemasFallsBackToJdbcSchemasWhenAllUsersIsMissing() throws Exception {
+        Method method = DbxJdbcPlugin.class.getDeclaredMethod("oracleListSchemas", Connection.class);
+        method.setAccessible(true);
+
+        try (Connection conn = DriverManager.getConnection("jdbc:h2:mem:dbx_oracle_no_all_users;DB_CLOSE_DELAY=-1", "sa", "")) {
+            conn.createStatement().execute("CREATE SCHEMA DM6_TEST_SCHEMA");
+
+            JsonNode result = (JsonNode) method.invoke(null, conn);
+            assertFalse(result.isNull());
+            assertEquals(true, result.isArray());
+            boolean found = false;
+            for (JsonNode node : result) {
+                if ("DM6_TEST_SCHEMA".equalsIgnoreCase(node.asText())) {
+                    found = true;
+                    break;
+                }
+            }
+            assertEquals(true, found);
+        }
+    }
+
     @Test
     void oracleEffectiveSchemaUsesExactOwnerBeforeUppercaseFallback() throws Exception {
         Method method = DbxJdbcPlugin.class.getDeclaredMethod("oracleEffectiveSchema", Connection.class, String.class);