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I am interested to know what other databases have features similar to Oracle's Flashback Query. It would seem that any database that supports MVCC could have the feature, but which do? SO has this question for SQL Server, but it seems more appropriate here.

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IBM DB2's Time Travel Query is somewhat similar. www-01.ibm.com/software/data/db2/linux-unix-windows/… –  Roy Nov 8 '12 at 9:47
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3 Answers

up vote 15 down vote accepted

PostgreSQL does not currently have it. But you are right, with MVCC it should theoretically be possible. In fact, the old university Postgres had an equivalent feature called time travel, but it was later removed because it caused too much overhead and the practical use was limited. While it would probably be possible to resurrect it, since then there have been many optimizations to the MVCC setup that would make it much harder.

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+1 Interesting information. –  Leigh Riffel Jan 6 '11 at 20:46
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The same functionality of Flashback Query can be achieved in SQL server by using database snapshots. The catch? This feature is only available in the Enterprise edition. You can read more about it here.

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I'll accept "same" in the sense that a bicycle and an automobile both provide transportation. Based on my limited understanding of SQL Server's database snapshots, the feature seems more like Oracle's flashback database except that the latter does continuous snapshoting and includes the data dictionary. –  Leigh Riffel Apr 21 '11 at 13:18
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The primary feature of flashback query is being able to query the data as of a point in time in the past by simply modifying the query itself. Data from the present and the past can be used in the same query and you can even query for for all versions of data in a particular time range. –  Leigh Riffel Apr 21 '11 at 13:19
    
Thank you for your input. It is good to know the closest functionality match. (+1) –  Leigh Riffel Apr 21 '11 at 13:20
    
Here is a situation in which Oracle's flashback query would be useful: dba.stackexchange.com/questions/995/get-back-deleted-record –  Leigh Riffel Nov 23 '11 at 16:24
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It's a pity that flashback feature is an addon in Oracle and only available in Enterprise Edition. DB2 10.1 has time travel query which is integrated into its database engine and available in all editions. You can download its free version from IBM and start using it right away!

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Not true. Oracle uses the word Flashback with several different features, some of which require Enterprise Edition, but Flashback Query is not one of them. Flashback Query is integrated in the database and available in all editions, even the free version. See oracle.com/us/products/database/product-editions-066501.html –  Leigh Riffel Nov 8 '12 at 15:48
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On the surface these DB2's time travel query does appear similar to Oracle's flashback query, but in the details they are quite different. It doesn't use MVCC and in some ways looks more like Oracle's Change Data Capture - docs.oracle.com/cd/E11882_01/server.112/e25554/…. –  Leigh Riffel Nov 8 '12 at 16:19
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