The `MPE_DATACATALOG_VARS` table catalogs variable attributes such as primary key status, not null constraints and index usage.
To trigger a scan, see the instructions [here](https://docs.datacontroller.io/admin-services/#refresh-data-catalog)
## Columns
-`TX_FROM num`: SCD2 open datetime
- 🔑 `TX_TO num`: SCD2 close datetime
- 🔑 `LIBREF char(8)`: SAS Libref (8 chars)
- 🔑 `DSN char(64)`: The library member name
- 🔑 `NAME char(64)`: The variable name
-`MEMTYPE char(8)`: The member type
-`TYPE char(16)`: The column type
-`LENGTH num`: The column length
-`VARNUM num`: The column position in the table
-`LABEL char(256)`: The column label
-`FORMAT char(49)`: The SAS format associated with the column
-`IDXUSAGE char(9)`: The column index type
-`NOTNULL char(3)`: The NOT NULL status
-`PK_IND num`: A flag to say whether the column is part of the primary key (1=PK, 0=Not PK). A Primary key column is identified by being in a constraint (or index) that is both UNIQUE and NOT NULL.