To use the Teradata ARC utility to perform a partial table copy, the table must have a Partitioned Primary Index (PPI) when a source staging table is not used. If you attempt to copy partial data from a non-partitioned table, and a source staging table is not used, an error results. ARC does not allow you to archive, restore, and copy a column-partitioned table or join index, including one with a primary AMP index, primary index, or no primary index. When forced to use ARC to partially move a column partition table or join index, Data Mover generates the error Cannot use ARC to copy partial data from a column partition table when a source staging table is not used.
Use the <sql_where_clause> and <key_column> tags to copy partial data with Teradata ARC, but specify the partitioning column in the WHERE clause. This is a Teradata ARC restriction and results in an error if the partitioning column is not specified in the WHERE clause.
Do not use the online archive setting when copying partial tables with Teradata ARC. This is a Teradata ARC restriction and results in an error if the online archive setting is used.
Data Mover creates a staging table when partial tables are copied with Teradata ARC. Archiving data using a WHERE clause with Teradata ARC archives the entire partition to which the qualifying rows belong. Therefore, the entire partition is copied to the staging table first. After the partition has been copied, only the required data (qualifying rows in the WHERE clause) is copied from the staging table to the target table.
For example, if a table is partitioned by month and you copy all rows WHERE DATE = '2013-03-08', Teradata ARC archives the entire partition of March because '2013-03-08' belongs to the March partition. The entire partition of March is copied to a staging table. The qualifying rows are then copied from the staging table to the target table where Date = '2013-03-08'.