1. Home
  2. Other Releases
  3. Cloud
  4. Guides
  5. Tours
  6. Concepts
    1. Aggregate filter
    2. Alias
    3. Apache Avro™
    4. Apache Kafka™
    5. Applied filter
    6. Base table
    7. Bookmark
    8. Business schema
    9. Business schema view
    10. Business schema view column
    11. Business schema view formula column
    12. Column
    13. Connector
    14. Dashboard filter
    15. Dashboard folder
    16. Dashboard runtime filter
    17. Data agent
    18. Data alert
    19. Data destination
    20. Date system variable
    21. Distinct filter
    22. Dynamic Field
    23. Expression
    24. External data source
    25. External session variable
    26. Filter expression
    27. Filter expression session variable
    28. Filter option
    29. Formula column
    30. Formula expression
    31. Full load
    32. Global variable
    33. Incorta Analyzer Table
    34. Incorta Analyzer Table column
    35. Incorta Analyzer Table formula column
    36. Incorta Analyzer View
    37. Incorta Analyzer View formula column
    38. Incorta SQL Table
    39. Incorta SQL View
    40. Individual filter
    41. Insight filter
    42. Internal query expression
    43. Internal session variable
    44. Join
    45. Join condition
    46. Join condition column
    47. Join filter
    48. Join filter column
    49. Level based measure
    50. Load filter
    51. Local data file
    52. Local data folder
    53. Materialized View
    54. Materialized View Column
    55. Materialized View Formula Column
    56. Measure filter
    57. Miscellaneous system variable
    58. Multi-Source table
    59. Physical schema
    60. Physical schema table
    61. Physical schema table column
    62. Physical schema table formula column
    63. Physical schema table runtime security filter
    64. Presentation variable
    65. Prompt
    66. Query system variable
    67. Runtime business view
    68. Runtime business view formula column
    69. Runtime security filter
    70. Session variable
    71. Shared Storage
    72. Upgrade Readiness
    73. Variable
    74. Visualization
  7. Tools
  8. References
  9. Integrations
  10. Data applications
  11. Releases

Concepts → Alias

About an Alias

An alias references a selected physical schema object. The selected object can exist within the same physical schema or another schema within the same tenant. An alias must have a unique name.

An alias immediately reflects any changes to and inherits the following properties from the selected table:

  • Columns
  • Runtime Security Filters
  • Joins*
  • Load Filter*
Note

The Schema Designer, Schema Diagram View, Table Editor, Join Editor, and Query Plan Viewer do not show implicitly inherited joins for an alias. The Table Editor does not show an inherited load filter for an alias.

It is not possible to create new columns, formula columns, runtime security filters, or load filters for an alias. It is possible to create new joins.

As a reference object, an alias only persists new join path data and not table data to shared storage. For this reason, it is not possible to perform a load for a specific alias.

Alias joins

From the selected table, an alias implicitly inherits all existing child joins and ignores all existing parent joins.

Newly created child and parent joins for an alias do not invalidate any existing child joins implicitly inherited from the selected table.

Here are the rules for alias joins:

  • an alias implicitly inherits all selected table child joins
  • an alias does not implicitly inherit selected table parent joins
  • explicitly defined child or parent joins for an alias do not invalidate any implicitly inherited selected table child joins

The following tools display alias joins explicitly created:

  • Schema Designer
  • Schema Diagram Viewer
  • Table Editor
  • Join Editor
  • Query Plan Viewer

With the Join Editor, you can explicitly create both child and parent joins for an alias. You can remove one or more joins the Table Editor.

Warning

Avoid cyclical joins with an alias table as this can generate a random query plan at runtime, causing inaccurate results.

Object data lineage

Starting with 2023.7.0, you can view the data lineage of aliases in the Data Lineage Viewer v2 that displays a diagram with the entities referenced in the alias table (upstream lineage) and entities where the alias table is referenced (downstream lineage). Additionally, you can view the data lineage per column or formula column in the alias table.

Alias example

Often, a child table contains two foreign keys to the same parent table. For example, in the sch_Sales schema, the tbl_Orders table contains two foreign key columns, BillToAddressID and ShipToAddressID. The tbl_Address table contains a primary key, AddressID.

In Incorta, only one join can exist between tbl_Orders and tbl_Address, such as:

sch_Sales.tbl_Orders.BillToAddressID = sch_Sales.tbl_Address.AddressID

By default, the join is a left outer join where tbl_Orders is on the left side of the join operator as the child table and tbl_Address is on the right side of the join operator as the parent table.

Support for a second join between tbl_Orders and tbl_Address on the ShipToAddressID foreign key requires an alias for the tbl_Address table.

Using the Schema Designer, you can create a new alias for the sch_Sales schema. In the Table Editor, you can specify the selected table, tbl_Address, and name the alias, atbl_Address. Then you can create a new parent join with the Join Editor such as:

sch_Sales.tbl_Orders.ShipToAddressID = sch_Sales.atbl_Address.AddressID

As a left outer join,tbl_Orders is on the left side of the join operator as the child table and atbl_Address is on the right side of the join operator as the parent alias.