Characteristics of Vertica projections based on 9.1 and 9.2 version?
hsaxena20
Community Edition User
Select three characteristics of Vertica projections.
A
Each projection contains all rows from the anchor table.
A projection can contain a subset of columns from the anchor table.
A projection can contain data from one or more anchor tables.
B
A projection can contain a subset of rows from the anchor table.
Each projection contains all columns from the anchor table.
A projection can contain data from one or more anchor tables.
C
Each projection contains all columns from the anchor table.
A projection can contain data from one or more anchor tables.
Each projection contains all rows from the anchor table.
D
A projection can contain a subset of columns from the anchor table.
A projection can contain data from only one anchor table.
Each projection contains all rows from the anchor table.
Answers
Looks like a question off of the Vertica Certification Exam!
This question is available in Vertica academy > Projections course.
The answer is D in this case.. i.e.
1. A projection can contain a subset of columns from the anchor table.
2. A projection can contain data from only one anchor table.
3. Each projection contains all rows from the anchor table.
No question about first point.
From 9.2 onwards perspective pre-Join projections are not supported so good with second point as well.
The third point talks about all rows from the anchor table, but Top K projection does not contain all the rows from the table.
@ersaurabhex - Per you comments (in which I agree) the answer to the question is:
E. None of the above
I remember taking the exam back in 2011 and I questioned these types of questions. I found out the exam at that time was written by a non-technical person and that lead to the inconsistencies.