What is rowid in oracle

While, you typically want your Primary Key to be a little more meaningful than a RowID, it is just a simple way of automatically ensuring uniqueness between rows. How are we doing? Please help us improve Stack Overflow. Take our short survey. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. ROWID oracle - any use for it? Ask Question. Asked 11 years, 6 months ago.

Active 3 years, 1 month ago. Viewed 79k times. Improve this question. Paolo Add a comment. Active Oldest Votes. Improve this answer. I now know an example for this. APC k 19 19 gold badges silver badges bronze badges. Randy Randy 16k 1 1 gold badge 34 34 silver badges 52 52 bronze badges.

The bad news is pretty bad. I have 2 tables, at beginin this f1 master and f2 detail, but when enduser insert rows he change restrictions 1 to 1, and confuse repeats no. February 02, - pm UTC. April 30, - am UTC. Not for a row in just any object. We have clustered tables whereby more than one tables data may be stored in a block. Note the first two rowids - they are the same.

Anto, April 30, - am UTC. And rows belonging to 2 different tables cannot have the same rowid except for clustering as you have demonstrated above - right? A reader, April 30, - am UTC. Just remember this: rowids are not unique in a database, rowids are only unique within and object. That is what you need to know - not the exceptions. What I'm worried is, people are asking just so they can go back to pretending that rowids are unique in a database.

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. So I really have no idea what you are referring to Question: How does and Oracle rowid uniquely define s rows location?

Also see my notes on Oracle Extended Rowid Format. The rowid is displayed as follows:. FFF is the relative file number. SSS is the slot number.

AAE is the relative file number. AAA is the slot number. The new parts of the rowid are the object number and the relative file number. Multiple files can have the same relative file number because Oracle assigns the number based on a tablespace.

This means that these numbers are unique only per tablespace, which means that you cannot derive an absolute address directly from the new rowid. This also means that the new rowid addressing scheme is tablespace-relative.