Fixing flyway#687 - flyway fails to clean tables that have Flashback …

…enabled

Added test case (once launched it will prevent any schema cleanup) and code that disables flasback during cleanup.

flyway-core/src/main/java/com/googlecode/flyway/core/dbsupport/oracle/OracleSchema.java

@@ -83,6 +83,10 @@ protected void doClean() throws SQLException {
             jdbcTemplate.execute(statement);
         }
 
+        for (String statement : generateAlterStatementsForFlashbackTables()) {
+            jdbcTemplate.execute(statement);
+        }
+
         for (String statement : generateDropStatementsForObjectType("TRIGGER", "")) {
             jdbcTemplate.execute(statement);
         }
@@ -128,6 +132,41 @@ protected void doClean() throws SQLException {
         }
     }
 
+    /**
+     * Generates the ALTER statements for all tables that have Flashback enabled.
+     *
+     * @return The complete alter statements, ready to execute.
+     * @throws SQLException when the statements could not be generated.
+     */
+    private List<String> generateAlterStatementsForFlashbackTables() throws SQLException {
+        List<String> alterStatements = new ArrayList<String>();
+
+        if (!flashbackAvailable()) {
+            LOG.debug("Oracle DBA_FLASHBACK_ARCHIVE_TABLES not available. No cleaning of Flashback tables.");
+            return alterStatements;
+        }
+        List<String> objectNames =
+                jdbcTemplate.queryForStringList("SELECT table_name " +
+                        "FROM DBA_FLASHBACK_ARCHIVE_TABLES WHERE owner_name = ?", name);
+        for (String objectName : objectNames) {
+            alterStatements.add("ALTER TABLE " + dbSupport.quote(name, objectName) + " NO FLASHBACK ARCHIVE");
+        }
+        return alterStatements;
+    }
+
+    /**
+     * Checks whether Oracle DBA_FLASHBACK_ARCHIVE_TABLES are available or not.
+     *
+     * @return {@code true} if they are available, {@code false} if not.
+     * @throws SQLException when checking availability of the feature failed.
+     */
+    private boolean flashbackAvailable() throws SQLException {
+        return jdbcTemplate.queryForInt("select count(*) " +
+                "from all_objects " +
+                "where object_name like 'DBA_FLASHBACK_ARCHIVE_TABLES'") > 0;
+    }
+
+
     /**
      * Generates the drop statements for all xml tables.
      *

flyway-core/src/test/java/com/googlecode/flyway/core/dbsupport/oracle/OracleMigrationMediumTest.java

@@ -270,6 +270,19 @@ public void xml() throws FlywayException {
         flyway.migrate();
     }
 
+    /**
+     * Tests support for cleaning of tables with Flashback/Total Recall enabled.
+     * Schema containing such tables has to be first cleaned by disabling flashback on each table;
+     */
+    @Ignore("Disabled due to missing flashback functionality in Oracle XE.")
+    @Test
+    public void flashback() throws FlywayException {
+        flyway.setLocations("migration/dbsupport/oracle/sql/flashback");
+        flyway.migrate();
+        flyway.clean();
+        flyway.migrate();
+    }
+
     /**
      * Tests support for reference partitioned tables.
      */

flyway-core/src/test/resources/migration/dbsupport/oracle/sql/flashback/V1__flashback.sql

@@ -0,0 +1,44 @@
+--
+-- Copyright 2010-2014 Axel Fontaine and the many contributors.
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--         http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+
+CREATE TABLE test (
+id number(10) not null,
+name varchar(20),
+primary key (id)
+);
+
+CREATE TABLE table1(
+  id number,
+  name varchar2(20),
+  test_id number(10) not null,
+  foreign key (test_id) references test(id)
+);
+
+-- unfortunately you need to specify archive name, but I do not have the permissions to create it in my environment
+-- so I will not even try to write it properly, with creating the archive from scratch
+alter table table1 flashback archive fda_trac;
+alter table test flashback archive fda_trac;
+--from now on you will be unable to delete the tables with plain DROP command
+
+insert into test values (1,'aaa');
+insert into test values (2,'aaa');
+insert into test values (3,'aac');
+
+update test set name = 'cccc';
+
+insert into table1 values (1,'daa', 1);
+
+commit;