Import destination tables

The table picker beside the Writeback tree lists the databases, schemas and tables of a destination, so you can bring the ones you need into Writeback. Import registers the tables and their columns. It does not copy any data.

Open the table picker

After you add a destination, the picker opens by itself. To open it later:

1. In the sidebar, open WriteBack.
2. In the tree, select a destination, a database or a schema.
3. Click the eye icon in the toolbar, labelled View destination. Or right-click the item and choose View Destination, or press Ctrl+U.

The picker opens beside the tree, and the left panel widens to fit it. Click the eye icon again to close it.

The right-click item appears only when the destination is ready. The toolbar button is off until you select a destination, a database or a schema, and while Batch Select is on. See The Writeback screen for the toolbar and the status badges.

Import tables

1. Expand the databases and schemas, or click Search and type part of a name.
2. Tick the tables you want. Tick a schema or a database to take in everything new under it.
3. Optional: preview a table before you import it. See the section below.
4. Click Check all to tick everything; the button then reads Uncheck all.
5. Hover over Import to see what you have selected, for example Import 2 schemas and 5 tables.
6. Click Import. The picker shows Importing... and locks until the import finishes.
7. When the import finishes, Import completed successfully. appears. The picker closes, and the tree moves to the destination.
8. Double-click a new table to configure it. See Configure a Writeback table.

New tables stay unmapped until you map at least one column. See Map columns.

How ticking works:

• Ticking a database or a schema ticks everything under it. When every item under a row is ticked, the row is ticked too.
• A row whose items are only partly ticked shows a filled state.
• Single-child branches open in one step, like in the tree.
• Tables and views sit under table and view groups inside a schema. The groups are organisers only; tick the items inside them.
• The number beside Import is read from the rows the picker has loaded, so expand the branches you care about before you import. The question below explains what it counts.

Search inside the picker

1. Click Search to open the box, marked Search....
2. Type part of a name. The list filters as you type, after a short pause, and keeps a match's parent rows so you can see where it sits.
3. If nothing matches, the list reads No results found for "...".
4. Click Search again, or press Escape, to close the box.

While a search is active, ticking a container covers only the rows you can see.

Preview a table before you import it

1. Hover over a table and click Preview, or double-click the table, or right-click it and choose Preview.
2. A window opens with up to 100 rows read from the destination, titled with the table's path. The window has search, column visibility and paging, and the picker has no control to change the number of rows.

If the preview cannot load, it reads Failed to load table data with a Retry button.

When there is nothing to import

When the picker has nothing to offer, a message replaces the list and you cannot tick anything.

If the picker cannot be read, it shows Failed to load source menu, the reason and a Retry button. Check the destination's connection, then retry. For other messages, see Writeback troubleshooting.

Settings and defaults

Permissions

• To browse a destination and preview its tables, you need View WriteBack Objects or Add/Modify WriteBack Objects.
• To import tables, you need Add/Modify Lake Objects. Add/Modify WriteBack Objects alone is not enough.

For the full list, see Writeback permissions and Who can do what in the Lake.

Limits and edge cases

• A table that is already in Writeback is not imported again. If you tick its schema, only the tables that are new come in.
• Computed (generated) columns are not imported, so you cannot map them.
• One import takes at most 500 new tables from a schema. If a schema holds more, the import stops with The schema contains too many tables for processing, maximum number per import is 500, consider splitting. Tick fewer tables and bring in the rest in later imports.
• While an import runs, the picker is locked. You cannot close it, change the selection or start another import, and its close button explains Please wait for import to complete.
• If the import is refused, a notification titled Error shows the reason the server returned. When no reason comes back, it reads An unexpected error occurred. See Writeback troubleshooting.
• If only some of your selection could be imported, the tables that were imported stay in Writeback. Open the picker again to bring in the rest.

Questions, answered

Why is Import denied even though I can add destinations?

Importing needs Add/Modify Lake Objects. Add/Modify WriteBack Objects does not allow it. Ask your administrator to grant it, or see Who can do what in the Lake.

Can I look at a table's data before I import it?

Yes. Hover over the table and click Preview, double-click it, or right-click it and choose Preview. The window shows up to 100 rows read from the destination, with search, column visibility and paging.

Why does the picker say "All tables imported"?

Every table the destination offers is already in Writeback. Create the new table in the destination, then open the picker again with View destination.

Why is a column missing after import?

Computed (generated) columns are never imported. If a column was added in the destination after you imported the table, run Sync Schema on the destination to add it; see Add and manage destinations.

Can I import a whole schema at once?

Yes. Tick the schema, and everything in it that is not yet in Writeback is imported. If the schema has more than 500 new tables, the import stops; see the next question.

What happens if a schema has more than 500 new tables?

The import stops with the error The schema contains too many tables for processing, maximum number per import is 500, consider splitting. Tick fewer tables in each import, and bring in the rest in later imports.

Which workflow do imported tables run on?

An imported table starts on the destination's (Standard) workflow, created when the destination was added. Change it per table on General, or move several tables at once: see Transfer tables between workflows. Schedules live in Run, schedule and monitor Writeback.

Does importing copy any data?

No. Import registers the tables and their columns. Data moves when the table runs.

How do I close the picker?

Click the button at the left of the picker's toolbar, labelled Close source menu. It is off while an import runs.

What does the number on the Import button count?

It counts your selection as the picker walks the tree it has loaded. A ticked schema counts alongside its tables; a collapsed database counts as one item until you expand it; tables count once their container is open. Every ticked row adds at least one, so the number never shows zero while Import stays enabled. Hover over Import to read the breakdown, for example Import 2 schemas and 5 tables.

If I close the picker and open it again, is my selection kept?

No. Each time it opens, the picker reads the destination's structure again and you tick what you need anew.