Projections are one kind of objects in Vertica where actual data for tables is stored. There can be multiple projections on a table but there will/should be atleast 1 projection which must have all the columns included in projection definition and such projections with all columns included are called 'Super Projection'. Other projections may be created considering usage of columns in the query and it may have few specific columns required for query. Each projection will have its own set of data.
SELECT EXPORT_OBJECTS('','schema_name.projection_name');
SELECT projection_schema, projection_name, projection_basename,is_super_projection FROM PROJECTIONS WHERE LOWER(anchor_table_name) = 'table_name' ;
Note: Value 'true' in is_super_projection column specify that it is a Super Projection.
select * from PROJECTION_REFRESHES where projection_name='projection_name' ;
Note:
SELECT projection_schema, projection_name, SUM (used_bytes) / (1024^3) AS size_in_gb FROM v_monitor.projection_storage WHERE LOWER(projection_schema) = 'schema_name' AND LOWER(projection_name) = 'projection_name' GROUP BY projection_schema, projection_name;
[Vertica][VJDBC](4268) ERROR: Only tables are allowed in FROM clause of projection [SQL State=42601, DB Errorcode=4268].
[Vertica][VJDBC](6372) ERROR: ORDER BY is not allowed in aggregate projection. The aggregate projection is automatically ordered on group by columns.
[Vertica][VJDBC](5600) ERROR: Invalid predicate in projection-select. Only PK=FK equijoins are allowed [SQL State=42601, DB Errorcode=5600].
[Vertica][VJDBC](5600) ERROR: Invalid predicate in projection-select. Only PK=FK equijoins are allowed [SQL State=42601, DB Errorcode=5600].