Replace a table's source

A BI table reads one deployed Lake or Warehouse table (Semantic models and BI tables). When that source changes, Replace table with... points the BI table at another table without rebuilding the model: the table keeps its name, id, measures and relationships, and columns are matched by name.

An update from a file never rebinds a BI table's source; use this dialog, then update from the file again (Model files).

Start a replace

You need edit access to the model and the Edit DataPrism Semantic Model permission. Start the replace from one of three places:

1. In the BI tables panel, right-click the BI table and choose Replace table with.... The item sits after Properties.
2. On the Diagram tab, use Replace table on the table's toolbar, between Edit table and Remove from semantic model.
3. In the BI table popup, click Replace in the header; the tooltip reads "Replace table with...: keep this BI table and read another core table."

The action is offered for saved models only. A popup opened from a report does not offer it, and in the model editor the popup disables it while you have unsaved changes ("Save or discard your changes first.").

Choose the new table

1. Pick a table in the picker. Search with Search core tables...; the tip reads "Choose a deployed Lake or Warehouse table this model's owner role can access. Tables marked Added are already in this model."
2. Tables already in the model carry an Added mark and cannot be picked. Click a row, then click Review.

Read the review

The dialog reads Checking the measures against the new table... while it builds the review. This step changes nothing.

The review opens with the old table and the new table, each with its Warehouse or Lake badge, and a Fact table badge when the table is the model's fact table. Then:

• Columns: how many columns keep their id and settings; the columns that are not in the new table and will be deleted, each with what uses it; the columns that change type, before and after, with each setting marked reset when it falls back to the new type's default; and the new columns that get default settings.
• Relationships: the relationships that use deleted columns and will be deleted (with the note "Revert recreates them under the same id."), relationships whose key changes type (their joins may fail), tables cut off from the fact table, and sort-by pairings that are removed.
• Measures: the check status line, like "<n> measures checked against the new table."; the measures that will turn red, each with its error; the measures that change type; and the measures that were not checked.
• Reports: "On deleted columns: <c> charts (<h> you cannot open), <f> report filters. They stay and break until fixed." plus the lists Reports with charts on deleted columns and Field parameters on deleted columns.
• Row-level security groups checked: each group, with whether it works on the new table.

When the replace is refused

If the review finds a blocking problem, the red banner This replace is refused comes first, the reasons follow it, and Replace stays disabled. Blocking reasons include:

• The BI table already reads that table: BI table "<T>" already reads core table "<Y>".
• The table is already bound by another BI table of this model: Core table "<Y>" is already in this semantic model as BI table "<U>". Pick another table, or remove "<U>" first.
• A new column's name would collide with a measure: Replacing the table of BI table "<T>" adds columns named like measures: <names>. Rename the measures first.
• Row-level security would break: a group filters a column the new table does not have, the check fails, a group's target would be cut off from the fact table, or a group would reach the fact table through another path. The reason tells you to update row-level security first (Row-level security and View as).
• The security check timed out: Row-level security could not be checked against "<table>" (the check timed out). Try again in a minute.

Fix what the reasons describe, then review again.

Warnings

Warnings do not block a replace. They list under Warnings in the review and in the result, and can include:

• A layer change: The new table is in the <layer> layer; "<T>" read a <layer> table until now.
• The new table gives the owner role no columns: The new table has no columns visible to the model's owner role.
• Public links and chart API tokens: This model has <n> active public links and <m> active chart API tokens; their viewers see the new table's data after the replace.
• Row-level security reach: the warnings name the groups whose rows can differ after the replace, so what their members see can change.

Apply and read the result

1. Click Replace. The dialog reads Replacing... the measures are checked again. and cannot be closed while this runs.
2. The dialog moves to Done. The result shows what actually changed, in the same sections: columns that were deleted, new columns that got default settings, measures that turned red, and relationship or sort-by changes.
3. If measures were not checked, a button offers Re-check the measure that was not checked, or the plural form for several, up to 500 measures at a time. If tests were queued for affected measures, the result adds "Tests of <n> measures were queued."

A replacement never deletes a measure: one that no longer works turns red until you fix it by hand or with the AI (Measures). Charts, report filters and field parameters are not changed by a replace; a chart on a deleted column stays and breaks until you fix it.

Undo a replacement

• Right after the replace, click Revert in Done. Later, open the model's History and click Revert in Table replacements.
• The confirmation explains: It reads <X> again: columns the replacement removed come back with their settings, relationships it removed are recreated, columns it added are removed. Settings changed since stay. Measures are never deleted.
• The result reads Reverted: "<T>" reads <X> again. and lists anything kept or not restored, with its reason, and how many measures are still red.
• Only the newest replacement of a table can be reverted, and one revert runs at a time. A revert is not previewed, and a revert cannot itself be undone; to read the newer table again, run a new replace.
• Table replacements keeps the newest 20 replacements. Each row names who replaced the source, the old and the new table, chips for what changed (columns removed, added, retyped, relationships removed, measures turned red) and its status: Applied, or Reverted by <name>.
• A Revert that cannot run is disabled with the reason in its tooltip, or answers with the reason: This table replacement was already reverted., BI table "<T>" was replaced again after this replacement; revert the newer replacement first., or This replacement cannot be reverted automatically, because work done since would be lost: <items>. Undo those changes or replace the table by hand. A revert also cannot restore a source that is no longer a deployed table visible to the model's owner role.

Replace from the AI panel

Model AI can replace a table's source for you. Ask in the model's AI panel; a replace waits for your approval except in Unrestricted, and you can revert it from History like any other replacement. Model AI never replaces a table that row-level security targets; use the dialog for that one. See Model AI.

Who can replace a table

Replacing and reverting need Edit DataPrism Semantic Model and edit access to the model; without them the actions are hidden. See Who can do what in DataPrism.

Questions, answered

Do I have to rebuild the model to read a different table?

No. Use Replace table with... and pick the new table. The BI table keeps its name, id, measures and relationships, and columns are matched by name.

What happens to column settings when a column's type changes?

A setting that still works for the new type is carried over; one that does not falls back to the new type's default, and the review marks each reset before you apply. The thousands separator and decimals survive a change between number types.

What happens to a chart that used a deleted column?

The replace does not change charts, report filters or field parameters. A chart on a deleted column stays and breaks until you fix it, and the review counts those charts, including ones you cannot open; they are counted, not named.

Can I replace a table that row-level security uses?

Yes, as long as the replace keeps the rules working. Row-level security is never rewritten, and the replace is refused when a group filters a column the new table does not have, when the check fails or times out, when a group's target would be cut off from the fact table, or when a group would reach the fact table through another path. Even a passing replace can change what members of a group see, and the warnings name those groups.

Why is Replace disabled?

The review found a blocking problem, so the banner This replace is refused lists the reasons and Replace stays disabled. It is also disabled while the review is still building and while the replace is applying. Fix the reasons, then review again.

The dialog says the model changed since the preview. What now?

Someone changed the BI table, the new table or the model after the review was built, so nothing was applied. The dialog rebuilds the review; read it, then click Replace again.

Can I undo a replacement?

Yes. Click Revert in Done, or open History > Table replacements and click Revert on the row. Columns and relationships the replacement removed come back, added columns are removed, and settings changed since stay. Only the newest replacement of a table can be reverted.

Why is a Revert button disabled in Table replacements?

That replacement cannot be reverted automatically. Hover the button to read why: it was already reverted, a newer replacement came after it, or undoing it would lose changes made since.

Why is Replace missing from a table popup?

A popup opened from a report does not offer it; open the model itself to replace a table. In the model editor, the button is disabled while the popup has unsaved changes ("Save or discard your changes first.").

Why do some measures show as not checked?

The check has a time budget, and the measures it does not reach keep their state and are listed with the reason. After the replace, use the re-check button in Done ("Re-check the measure that was not checked", or the plural form, up to 500 measures).

Who can replace a table?

Anyone with Edit DataPrism Semantic Model and edit access to the model. Reverting needs the same rights. See Who can do what in DataPrism.