Orchestration
What is a dependency graph?
A dependency graph records which columns depend on which, so an edit invalidates only descendants.
Updated · Part of What is a computed column?
How it works
- Each computed column names its inputs.
- The graph is the set of those edges.
- Invalidation follows the edges from the edited value.
What it is not
It is not a task DAG you schedule, and it is not a README that describes the pipeline.
dependency graph: this, and the thing it is confused with
| This | Not this | |
|---|---|---|
| Nodes | Columns and rows | Jobs |
| You edit | A value or an expression | A schedule |
| Effect | Descendant rows | Every downstream job |
Where Pixeltable fits
Pixeltable builds that graph from the expressions on the classes. The local dashboard can show it.
Questions
- How does dependency graph work?
- Each computed column names its inputs. The graph is the set of those edges. Invalidation follows the edges from the edited value.
- What is dependency graph often confused with?
- It is not a task DAG you schedule, and it is not a README that describes the pipeline.