What is the Daml Ledger Model? [2021]

Captions as YouTube publishes them, usually machine-generated, so names such as Daml and Canton can be misheard.

1. 0:01

   hi everyone today i'm going to talk about one of the key concepts of demo the demo ledger model now before we go into what the ledger model is i'll talk a minute about why we need a ledger model so as you may recall demo was designed to make it easy efficient and safe to build multi-party applications now in order to make it easy efficient and safe to build the applications we need to make it simple to build them

2. 0:34

   so the demo ledger model is a conceptual model of a demo runtime that makes it feel as if we are writing an application or running an application against a centralized database and that makes it easy for the developer and the operations team to reason about their application so when we talk about a demolition model we think of a virtual shared ledger and i'll unpack those three words one by one by ledger we mean a permanent record of

3. 1:13

   data you can think of this as similar to a regular database by shared we mean the ledger can be serving multiple parties now because we are conceptually talking about a single ledger all of these parties have a consistent view so for example if we have alice bob and charlie all running a demo application against this ledger they all feel as if this application is running against a centralized ledger now virtual means that this ledger doesn't necessarily

4. 1:53

   exist in one place while alice bob and charlie feel as if they're talking to a single ledger the infrastructure may actually be distributed so the important takeaway is that for the developer and for the user operating the application it feels as if they have a single ledger but actually the data may be be distributed using a blockchain or another distributed ledger technology

5. 2:24

   now the this idea that i want my distributed ledger to feel like a centralized ledger it may seem simple and it may actually feel seem obvious but this isn't trivial it's actually one of demos main differentiators compared to other technologies this idea that the developer doesn't need to think about building an application for a distributed setting that the developer builds an application for the demo ledger model and that application can run

6. 2:57

   using the different demo drivers on either a centralized database such as postgres or amazon's qldp or on a distributed blockchain such as hyperledger fabric corda or vmware blockchain that's a simple idea that's really non-trivial now another important part of the ledger model is that it precisely defines all of the quality attributes of any demo ledger so while this presentation is high level the ledger model actually has a

7. 3:35

   precise mathematical definition of different attributes such as consistency privacy and so forth i have a link at the end for anyone who wants to dive into the details and the precise definitions of each attribute using this model demo users have a common nomenclature to compare the different databases and blockchains so for example the demo ledger model allows all data to be archived

8. 4:04

   but hyperledger fabric doesn't have the capability to delete data it's a immutable blockchain if we look at consistency and privacy which exists in the demo electric model corda for example has two main configurations it can run with a validating notary or a non-validating notary and you don't have to understand exactly what that means but one of those configurations has stronger consistency and weaker privacy the other one has stronger privacy and weaker consistency

9. 4:36

   now having precise definition a precise mathematical model for the ledger and for all these attributes allows demo users to be explicit about the technology choice that they make and importantly the application developer can build against the ledger model separately the security and operations team can independently evaluate which underlying technology best suits the organization's needs one more added benefit is that this ledger model allows us

10. 5:06

    digital asset to work with the different ledger providers our partners and help them close any gaps that they have in any of the attributes of their underlying ledgers to give an overall better solution so to recap the demolition model is a conceptual model that makes it that the developer the operator and the users of demo applications reason about the application and feel as if they're using a single virtual shared ledger even though this application may be a

11. 5:38

    distributed runtime for more information you can go to demo.com and go to docs.damo.com that has the background concepts of demo and for any questions you can go to disqus.demo.com and engage with us in the community now before i end i'll quickly go into this link just to show this is where in the documentation we have the demo ledger model and as you can see it starts high level as we showed in the presentation but you can even you can then dive into

12. 6:15

    any of these attributes for example and go into the precise definitions of what consistency means in the context of dell so that's it i hope this was helpful thank you you