3 ms·

The SQL database has more than a dozen semi-independent applications that treat different aspects of the manufacturing process, for example from recipes and bat

The SQL database has more than a dozen semi-independent applications that treat different aspects of the manufacturing process, for example from recipes and batches to maintenance, scrap management and raw material inventory. The data is interlocked, the apps are independent as different people in very different roles are using it. No, it never starts in the front end, it started as a system and evolved by adding more data and more apps. Think SAP as another such example.

mdavid626 1y ago
This is and “old-school” design. Nowadays I wouldn’t let apps meet in the database. Simple service oriented architecture is much preferred. Each app with its own data. Then such problems can be easily avoided.
- dakiol 1y ago
  It’s not old school, it’s actually solid design. I have worked too with people that think the frontend or even services should guide the design/architecture of the whole thing. Seems tempting and it has the initial impression that it works, but long terms it’s just bad design. Having Data structures (and mainly this means database structures) stable is key to long term maintenance.
  - radlad 1y ago
    > Seems tempting and it has the initial impression that it works, but long terms it’s just bad design. This appears as an opinion rather than an argument. Could you explain what you find bad about the design? In any case, I believe a DB per backend service isn't a decision driven by the frontend - rather, it's driven by data migration and data access requirements.
    - dakiol 1y ago
      It's an opinion based on countless of references and books out there. I cannot cite them, but it's like "code should be designed to depend on abstract interfaces instead of a concrete implementation", "everything is a byte stream", "adding more people to a late project makes it later", "Bad programmers worry about the code. Good programmers worry about data structures and their relationships", "Show me your flowchart and conceal your tables, and I shall continue to be mystified. Show me your tables, and I won't usually need your flowchart; it'll be obvious.", etc... they are usually true.
    - RaftPeople 1y ago
      > In any case, I believe a DB per backend service isn't a decision driven by the frontend - rather, it's driven by data migration and data access requirements. I think the idea of breaking up a shared enterprise DB into many distinct but communicating and dependent DB's was driven by a desire to reduce team+system dependencies to increase ability to change. While the pro is valid and we make use of the idea sometimes when we design things, the cons are significant. Splitting up a DB that has data that is naturally shared by many departments in the business and by many modules/functional areas of the system increases complexity substantially. In the shared model, when some critical attribute of an item (sku) is updated, then all of the different modules+functional areas of enterprise are immediately using that current and correct master value. In the distributed model, there is significant complexity and effort to share this state across all areas. I've worked on systems designed this way and this issue frequently causes problems related to timing. As with everything, no single solution is best for all situations. We only split this kind of shared state when the pros outweigh the cons, which is sometimes but not that often.
      - mdavid626 1y ago
        I disagree. I generally understand the problem a "split-up" database brings to the table. This is how people designed things in the last many decades. What I propose is to leave this design behind. The split up design fits modern use cases much better. People want all kind of data. They want to change what data they want rather often. "One" database for all of this doesn't really work -- you can't change the schema since it's used by many applications. So, you'll stuck with a design coming from a time when requirements were probably quite different. Of course, you can make some modifications, but not many and not fundamental ones. In the split-up design, since you're not sharing the database, you can do whatever you want. Change schema as you see fit. Store data in multiple different forms (duplicates), so it can be queried quickly. The only thing you have to keep is the interface to the outside world (department etc.). Here you can use eg. versioning of your API. Handy. The 90's are over. We don't have to stick to the limitations people had back then. Yes of course, data not being up-to-date in every system can be a problem. BUT business people nowadays tend to accept that more, than the inability to change data structures ("we can't add a new field", "we can't change this field" etc.).

mdavid626 1y ago

This is and “old-school” design. Nowadays I wouldn’t let apps meet in the database. Simple service oriented architecture is much preferred. Each app with its own data. Then such problems can be easily avoided.

dakiol 1y ago
It’s not old school, it’s actually solid design. I have worked too with people that think the frontend or even services should guide the design/architecture of the whole thing. Seems tempting and it has the initial impression that it works, but long terms it’s just bad design. Having Data structures (and mainly this means database structures) stable is key to long term maintenance.
- radlad 1y ago
  > Seems tempting and it has the initial impression that it works, but long terms it’s just bad design. This appears as an opinion rather than an argument. Could you explain what you find bad about the design? In any case, I believe a DB per backend service isn't a decision driven by the frontend - rather, it's driven by data migration and data access requirements.
  - dakiol 1y ago
    It's an opinion based on countless of references and books out there. I cannot cite them, but it's like "code should be designed to depend on abstract interfaces instead of a concrete implementation", "everything is a byte stream", "adding more people to a late project makes it later", "Bad programmers worry about the code. Good programmers worry about data structures and their relationships", "Show me your flowchart and conceal your tables, and I shall continue to be mystified. Show me your tables, and I won't usually need your flowchart; it'll be obvious.", etc... they are usually true.
  - RaftPeople 1y ago
    > In any case, I believe a DB per backend service isn't a decision driven by the frontend - rather, it's driven by data migration and data access requirements. I think the idea of breaking up a shared enterprise DB into many distinct but communicating and dependent DB's was driven by a desire to reduce team+system dependencies to increase ability to change. While the pro is valid and we make use of the idea sometimes when we design things, the cons are significant. Splitting up a DB that has data that is naturally shared by many departments in the business and by many modules/functional areas of the system increases complexity substantially. In the shared model, when some critical attribute of an item (sku) is updated, then all of the different modules+functional areas of enterprise are immediately using that current and correct master value. In the distributed model, there is significant complexity and effort to share this state across all areas. I've worked on systems designed this way and this issue frequently causes problems related to timing. As with everything, no single solution is best for all situations. We only split this kind of shared state when the pros outweigh the cons, which is sometimes but not that often.
    - mdavid626 1y ago
      I disagree. I generally understand the problem a "split-up" database brings to the table. This is how people designed things in the last many decades. What I propose is to leave this design behind. The split up design fits modern use cases much better. People want all kind of data. They want to change what data they want rather often. "One" database for all of this doesn't really work -- you can't change the schema since it's used by many applications. So, you'll stuck with a design coming from a time when requirements were probably quite different. Of course, you can make some modifications, but not many and not fundamental ones. In the split-up design, since you're not sharing the database, you can do whatever you want. Change schema as you see fit. Store data in multiple different forms (duplicates), so it can be queried quickly. The only thing you have to keep is the interface to the outside world (department etc.). Here you can use eg. versioning of your API. Handy. The 90's are over. We don't have to stick to the limitations people had back then. Yes of course, data not being up-to-date in every system can be a problem. BUT business people nowadays tend to accept that more, than the inability to change data structures ("we can't add a new field", "we can't change this field" etc.).