When materialization takes long time "View not found" error when querying document

[adzialocha]

Querying a document (which exists) by documentId sometimes returns this error:

{
  "response": {
    "data": null,
    "errors": [
      {
        "message": "View not found"
      }
    ],
    "status": 200,
    "headers": {
      "map": {
        "content-length": "53",
        "content-type": "application/json"
      }
    }
  },
  "request": {
    "query": "\n    query FetchBoard($documentId: String!) {\n      board: zoo_adventures_00209403784eea2ba5236f9083472f040a90babf4df1b64efbbaae58eb51aa67fd4d(id: $documentId) {\n        meta {\n          viewId\n        }\n        fields {\n          game_field_1 game_field_2 game_field_3 game_field_4 game_field_5 game_field_6 game_field_7 game_field_8 game_field_9 game_field_10 game_field_11 game_field_12 game_field_13 game_field_14 game_field_15 game_field_16\n        }\n      }\n    }\n  ",
    "variables": {
      "documentId": "0020c301d6595e12cbd472d21ac4c1bdfde02ec4e8d7ea299f723130d64eb65e500d"
    }
  }
}

The error comes from this line: https://github.com/p2panda/aquadoggo/blob/main/aquadoggo/src/graphql/client/utils.rs#L22

It often happens right after when the document gets updated. Maybe it gets temporarily deleted in the database before the new materialized version gets inserted? The document has a fairly large operation graph ..

[sandreae]

Maybe it gets temporarily deleted in the database before the new materialized version gets inserted?

We aren't deleting views in the db at the moment, so I don't think it's this.

I suspect it is happening as the document table is updated first, then the view inserted to document_views table (if the document isn't deleted). So if we queried the document_view table in this moment then we wouldn't find anything. Like this this:

A1) document table updated with new view id (the isn't inserted yet)
B1) query the document for it's newest view
B2) query the document_views table for the retrieved view -> Error!
A2) insert the new view to the document_views table

We can fix this by adding a transaction around these two sql queries 👍

Side thought, it makes me wonder if we need to think about best practice for how we query documents/views, maybe getting the document id and querying that is the most reliable way, seeing as views may be deleted.

[adzialocha]

We can fix this by adding a transaction around these two sql queries 👍

Super! Sounds good. Everything which needs multiple writes before it's considered a "final" state should be wrapped into one transaction, maybe we find more of these in other places?

[sandreae]

maybe we find more of these in other places?

Yes, maybe!