In PostgreSQL, the MVCC concurrency control mechanism says that: MVCC locks acquired for querying (reading) data do not conflict with locks acquired for writing data, and so reading never block...

I have located many resources on the web giving general overviews of MVCC (multi-version concurrency control) concepts, but no detailed technical references on exactly how it should work or be impl...

MongoDB is to me a great database. However there are cases where I really need atomic multi-document transactions. For example to transfer things (like money or reputation) between accounts and thi...

Is it possible to query how many multiversioned rows are there in a db ? We want to measure the impact of pg_dump on a production database, and to suspend it in case of need: is it creating too ma...

I'm running PostgreSQL 9.5.3. I am trying to understand why I see a difference in behavior between the two routines below. I find this behavior counter-intuitive, but there may be a very good reas...

Question Summary This is a question about serializability of queries within a SQL transaction. Specifically, I am using PostgreSQL. It may be assumed that I am using the most current version of P...

Postgress follows MVCC rules. So any query that is run on a table doesn't conflict with the writes that happen on the table. The query returns the result based on the snapshot at the point of runni...

How can I add a checkbox to each row of a MVCcontrib grid. then when the form is posted find out which records were selected? I Am not finding much when searching for this. Thank you

I am interested in keeping a running history of every change which has happened on some tables in my database, thus being able to reconstruct historical states of the database for analysis purposes...

What do DBMSs that implement multi-version timestamp ordering for concurrency control usually include in their write-ahead logs ? before and after images, or one of them ? timestamps ? what else ? ...

Greetings Overflowers, To my understanding (and I hope I'm not right) changes to indices cannot be MVCCed. I'm wondering if this is also true with big records as copies can be costly. Since recor...

I have a very large database table in PostgresQL and a column like "copied". Every new row starts uncopied and will later be replicated to another thing by a background programm. There is an partia...