Create a Computed Join
This page documents the Add Computed Join form, then walks through the steps to create one from the datastore container list. For the conceptual overview, see How Computed Join Works.
Permissions
You need Editor permission on the left datastore, or Author permission plus ownership of the new container. You also need at least Viewer permission on the right datastore. See Computed Join Permissions for the full matrix.
Field Reference
The Add Computed Join form is grouped into four blocks. The numbered annotations on each screenshot match the REF. column in the table below it.
Name and Join Type
| REF. | Field | Description |
|---|---|---|
| 1 | Name | Unique name for the Computed Join container on the parent datastore. All spaces are replaced by underscores. Max 255 characters. |
| 2 | Join Type | One of Inner Join, Left Join, Right Join, or Full Outer Join. Defaults to Inner Join. |
Left Reference and Right Reference
The screenshot shows two blocks, Left Reference and Right Reference, each containing the same four fields (Datastore, Container, Field, Prefix).
| REF. | Field | Description |
|---|---|---|
| 1 | Datastore (Left Reference) | Locked to the datastore you opened. The Computed Join lives under this datastore. |
| 2 | Container (Left Reference) | Profiled container to join from the left side: table, view, file, Computed Table, or Computed File. |
| 3 | Field (Left Reference) | The column used as the join key on the left side. Must resolve to the same data type as the Right Field; mismatched types surface as a validation error when you click Validate or Save. |
| 4 | Prefix (Left Reference) | Prefix applied to every column from the left side in the joined result. Defaults to left. Max 100 characters. |
| 5 | Datastore (Right Reference) | Datastore for the right container. Can be the same as the left datastore or a different one. You need at least Viewer permission on it. |
| 6 | Container (Right Reference) | Profiled container to join from the right side. Same supported types as Left Container. |
| 7 | Field (Right Reference) | The column used as the join key on the right side. Must resolve to the same data type as the Left Field. |
| 8 | Prefix (Right Reference) | Prefix applied to every column from the right side. Defaults to right. Max 100 characters. Should differ from the Left Prefix when both sides share column names; identical prefixes trigger a duplicate-column error at Validate. |
Select Expression, Filter Clause, and Group By Clause
| REF. | Field | Description |
|---|---|---|
| 1 | Select Expression | SQL select clause naming the columns to include in the joined result. Auto-fills with every top-level field from both sides, prefixed. Edit it to keep only what you need, add aliases, or include expressions. |
| 2 | Filter Clause | Optional. Post-join WHERE predicate applied to the joined result. |
| 3 | Group By Clause | Optional. Group By columns when the Select Expression uses aggregation functions. Every non-aggregated column in the Select Expression must appear in this clause. |
Description, Owner, and Additional Metadata
| REF. | Field | Description |
|---|---|---|
| 1 | Description | Free-text description of the Computed Join (max 255 characters). Surfaces alongside the container in lists and search results. The form can auto-suggest a description from the join configuration. |
| 2 | Owner | The user who owns the Computed Join. Defaults to the user creating the join. Only Editors can pick a different owner at create time; Authors are locked to themselves. |
| 3 | Additional Metadata | Optional key-value metadata attached to the container. |
Steps
Step 1: Open the datastore where the Computed Join will live and click Add.
Step 2: Choose Computed Join from the dropdown.
Step 3: The Add Computed Join modal appears.
Step 4: Fill in the form using the Field Reference above, then click Validate. A Validation Successful message appears if the SQL parses and the schema resolves against the input containers.
Step 5: Click Save. A success message appears, the modal closes, and the new Computed Join opens.
