Managing Table Projections

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Table Projections are subsets of a full table in the VAST Database that allow for optimized queries that use only the columns included in the projection. You can select up to four columns to be used to sort the projection, and an unlimited number of additional columns to include in the projection, which are not used to sort the projection.

Managing Table Projections using the  VAST Web UI

Viewing Table Projections

  1. From the left navigation menu, select DataBase and then VAST DB, to show a list of all databases.

  2. Expand the relevant database, then under the database, expand the schema to which the table belongs, and then under the schema expand the table of interest. If the table has any projections, they are displayed as children of the table.

  3. Select a projection to show details of the columns included in the projection.

Creating a Table Projection

  1. From the left navigation menu, select DataBase and then VAST DB, to show a list of all databases.

  2. Select the database, schema, and table in which the projection will be created.

  3. Click Add Projection. Enter a name for the projection.

  4. Select the columns that will be included in the projection. Select up to four columns that are sorted, and an unlimited number of unsorted columns.

    Note

    Rows in the projection are sorted according to the columns selected as 'sorted', in the order the are selected. So, if you select columns A, B, C, and D as sorted, the rows in the projection are sorted according to the values in these columns, in this order.

  5. Click Create.

Renaming a Table Projection

  1. From the left navigation menu, select DataBase and then VAST DB to show a list of all databases.

  2. On the left, select a database, schema, table, and projection. Details are shown of the projection.

  3. Click edit-symbol.png next to the projection name, and then edit the name.

  4. Click Save.

Deleting a Table Projection

  1. From the left navigation menu, select DataBase and then VAST DB to show a list of all databases.

  2. On the left, select a database, schema, and table. The projections for the table, if any, are shown below the table.

  3. Select a projection. Details are shown of the projection.

  4. Click Three-dots-symbol.png, and then select Delete.

Managing Table Projections using the VAST CLI

Use these VCLI commands to manage table projections on VAST Database tables.

Action

Command

Create a projection in a table

projection create

LIst all projections in a table

projection list

Show details for a projection

projection show

Rename a projection

projection rename

Delete a projection

projection delete

List the columns in a projection

projectioncolumn list

Show details for a column in a projection

projectioncolumn show