Update with rowid oracle

Now we see how to delete the duplicate records from the products table in different ways. Want to write an plsql code to update a single record using rowid where all the rows are duplicated could someone help me in this case. A rowid is assigned to a row upon insert and is immutable never changing , changes happen only inthe following situations.

Cdata 1 1 x xxxx 2 1 x xxxx. And finally I got the solution as. Here you can use both rank and densrank since both will give unique records when order by rowid. Rowid, Rownum are the Pseudo columns in oracle used to select the data from tables. If you delete and reinsert a row with the Import and Export utilities, for example, then its rowid may change. If you delete a row, then Oracle may reassign its rowid to a new row inserted later. Oracle Database rowid values contain information necessary to locate a row: The data object number of the object The data block in the datafile in which the row resides The position of the row in the data block first row is 0 The datafile in which the row resides first file is 1.

Removing duplicate rows from Oracle tables with SQL can be very tricky, and there are several techniques for identifying and removing duplicate rows from tables: Delete multiple duplicate rows Subquery to identify duplicate rows Use RANK to find and remove duplicate table rows.

Here you will see or analyse that for the duplicate records the rowids are different. So our logic is fetch the records where the rowid is maximum. They aren't and if you ever make that assumption, you will have a bug in your code just waiting to happen.

I don't know why you would jump to that conclusion. Hi Tom The first question: somebody ask me when does a column of a table add or alter but i don't know The second question: 11g tells me i can create a trigger with order,so how to write it? July 19, - am UTC. You would have to set up your own auditing if you wanted that.

We usually use configuration management software for things like that you know - documentation - so you cannot only see WHEN something took place but more importantly - infinitely more importantly - WHY something took place Yes you can order the triggering firing order in 11g - but you know what - if you feel the need to - I know for a fact you have a bad design. You should in order a not use a trigger at all. Is there any risk in using rowid along with outer joins as in the query below?

It is known that neither the table table1 nor table2 has a primary key. It is also known that row movement is disabled and there is going to be only one session which is going to operate. June 04, - am UTC. Assuming this query will execute fine, but will it update those records of table1 that we intend to? And is there any risk involved? June 05, - pm UTC. A reader, June 08, - am UTC. I know use only rowid is not a good idea, when we did not get lock of it and concurrently some other session delete and insert new row which reuse this rowid.

Why not just use primary key? As primary key already uniqly identify the record. June 08, - am UTC. If the row was deleted and someone inserted a new row that just happened to reuse that rowid - then the rowid will 'find' a row but the primary key will "unfind it" The primary key would suffice, however, it would require an unique unique scan of an index - so the rowid could offer a performance benefit.

A reader, September 26, - pm UTC. Hi Tom, We are currently working on migrating data different two versions of same tool Argus - Oracle Provided. For each table migration we have two different scripts 1.

Migration script developed by Dev Engineers 2. Validation scripts developed by QA Engineers For each table there is a common understanding between the development team and the QA team as to how to identify a single row in the table.

We cannot alter the schemas and underlying tables to add or delete columns. The major challenge is always with tables having composite keys. For example a common reoccurring primary key configuration at table level is EmpID and SeqNum Employee table analogy where SeqNum is generated at runtime. These SeqNum's always vary across the versions of the systems. Once the validation process is done then all the columns used specifically for the migration process would be cleaned up.

I Developer have hit across a table that does not a primary key at table level. No combination of columns gives me a unique set of records. I was thinking along the lines of dumping the RowID in one of the varchar columns and clean it up after migration. When the migration process is going on there would not be any activity on the old system So no DML's.

The QA team would be basically picking this RowID from the new system and then go to old system and pick up the row and validate? Thanks a lot for patiently reading this lengthy post and as always for sharing your wisdom. Thanks and Regards Nand Kishore Sagi.

October 10, - pm UTC. Hi Tom, What is the partition key we are referring here? In this scenario, is it ok to use rowid's to update this table? March 25, - am UTC.

I don't know what partition key you are thinking about - this is a big page, hasn't been updated in many months, the review was not about partitioning.