Oracle mistakenly deletes data, mistakenly modifies data recovery ____oracle

SELECT * from Com_parameter (table name) as of timestamp to_timestamp (' 2015-08-03 9:00:00 ', ' yyyy-mm-dd HH24:MI:SS ')

    This SQL statement is the table data that is used to find the point at which a table is in a particular feature. If you accidentally deleted the table data at 9:05, you can use this SQL to retrieve the data before the deletion,
but note that the time cannot be too long, preferably within one hours or half an hour, I haven't tried it for a long time and you can try it if you are interested.

    Here are two ways, the most simple and brutal of course is the current table of the entire empty, and then check out the wrong delete before the entire coverage of the data, but this will always make people feel the heart is not practical,
of course, if the test data then casually do it. The

    second option, and also the recommended option, is to use another SQL

Update a
set a.value=b.value from
table1 a,table2 b where a.id=b.id

This SQL can take a column field of table A in the database, update to a column field in the B table in the database, where the following condition can be omitted, if only a few rows of records are updated, and the Where Condition
    uses the second method to recover the erroneous deletion data in a more secure situation, The modified data can also be recovered by this method.