assertAppendOnly
The assertAppendOnly method returns a copy of the source table or the source table itself if it is already an append-only table, with the append-only attribute set.
The source table's update pattern must already conform to append-only semantics. If it produces an update that does not conform to append-only semantics, then the returned table will notify of an error and cease updating.
If the engine can identify a table as append only, then some query operations may be optimized (for example, a lastBy operation need only track the current last row per-group rather than all of the rows in a group). In formulas, the i (for the current row position), ii (for the current row position), and k (for the current row key) variables can be used safely.
Syntax
table.assertAppendOnly()
Parameters
This method takes no arguments.
Returns
A new Table with the append-only attribute set.