Thursday, September 7, 2017

Marten–Soft Deletes

On one of my projects we are using Marten, which provides a Document Store and Event Store api on top of PostgreSQL.  Behind the scenes it uses the powerfull JSON functionality that is built into the PostgreSQL database engine. The fact that we are still using an ACID compliant database makes it all a lot easier.

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One of the features that Marten supports are ‘soft-deletes’. This means that documents are never actually deleted from the database. Marten will automatically filter out documents marked as deleted unless you explicitly state otherwise in the Linq Where clause.

However when requesting a specific document I noticed that I still got my deleted document back;

var document=await session.LoadAsync(id);

If I used the query syntax instead the specific document was filtered out as expected:

var documents=await session.Query().Where(s => ..);

The following GitHub issue brought some insights: https://github.com/JasperFx/marten/issues/808 . This functionality is by design, if you know the id of the document you’ll get it back. Load will not respect the deleted flag.

Good to know!

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