CDAP has different naming conventions for different entities in CDAP. We distinguish these different character sets, and note which entities use them:
Alphanumeric Character Set
This is the basic character set that all entities support:
Alphanumeric characters (
a-z A-Z 0-9)
Alphanumeric Extended Character Set
Namespace IDs can use an alphanumeric extended character set:
Alphanumeric characters (
a-z A-Z 0-9)Underscores (
_)
Alphanumeric Extra Extended Character Set
Except as noted on this page, all other CDAP entities (such as apps and plugins) support an alphanumeric extra extended character set:
Alphanumeric characters (
a-z A-Z 0-9)Hyphens (
-)Underscores (
_)
Note that datasets whose names begin with an underscore (_) will not be visible in the home page of the CDAP UI, although they will be visible elsewhere in the CDAP UI.
Dataset Character Set (Deprecated)
In earlier versions of CDAP, Dataset names used the alphanumeric extra extended character set, plus periods:
Alphanumeric characters (
a-z A-Z 0-9)Hyphens (
-)Periods (
.)Underscores (
_)
We recommend that instead you use the Alphanumeric Extra Extended Character Set, as support for this may be removed in the future.
Hive Limitation and Conversion
Hive 0.12 only supports the alphanumeric extended character set: alphanumeric characters (a-z A-Z 0-9) and underscores (_).
As a consequence, any hyphens or periods in dataset names will be converted to underscores while creating Hive tables.
Example:
The datasets
my-datasetmy_datasetmy.dataset
will all be converted to
dataset_my_dataset
Names should be carefully constructed to avoid any collisions as a result of conversion.
Note that if you configure the Hive table name using the explore.table.name property (see Data Exploration), then the value of that property is used literally; that is, no prefix is added and no character conversion takes place.