I am getting this message while trying to select unique records on a text field in a 49 million row table with just 5 columns. My case appears to be identical to the unique selection on a text filed described in Help. I doing this via the Select dialog boxes -

Select / Unique / <table> / <field> / Condition: unique / ignore case, ignore whitespace / Action: replace selection

The values in the <field> look like this: f291552e-f2bc-485d-ac7d-116fd1c49a8d

Is the table too large and that is why the Select query will not work?

Is the table too large and that is why the Select query will not work?

No. It's something else. To help you find what it is, post details on what you're doing and, ideally, a sample of the .map. Your table, of course, must be selectable as described in the Selection topic, for example:

A table, or a drawing's table, must have a key field with a btree index (and not a btreedup or some other form of index) in it for selection to work. If the table does not have a btree index, selection will not be available. To add an index to a table that does not have an index, see the Add an Index to a Table topic.

Can you select records in the table interactively (Ctrl-click a record using the cursor)? If not, does the table have a unique index (check its schema, if you don't know how to do that, select the table component in the Project pane, then click Copy in the Project pane toolbar, then paste the result as a text into, say, Notepad, and post it here -- the pasted text will contain the description of the schema)?