ERROR 3586: Insufficient projections to answer query

Hi,

  The following might be the possible reasons for such error

1) There is no projection that has all of the columns needed by a query.
 2) A node is down and you have not defined a K=1 physical schema.

-Regards,

 Sruthi

Hi Sruthi,

I had found those potential reasons in the documentation, but the k-safety reasoning doesn't apply at all since I didn't even manipulate the nodes, just a single table in a schema. As for the projections, I had tried the select query on the projection itself, which had worked, but it seems like whenever the schema is used to reference the table, I get the original error message. 

Hi,

 Could you please check if any node is marked as ephemeral? issue select * from nodes

-Regards,

 Sruthi

All 3 nodes are not marked as ephemeral.

Hi,

  All nodes should be in status UP. if the node is marked ephemeral, then projection is not at Ksafe 1. 

-Regards,

 Sruthi

Hi,

  Can you check if is_up_to_date column for the projection you are trying to backup is t?

issue select * from projections;

-Regards,

 Sruthi

They are not up to date. 

Hi,

  They have to be up to date in order to take backup of the table. Projections must be up to date to be used in queries. In order to make projections up to date, you need to refresh them. issue the command

select REFRESH('tablename') 

If you run REFRESH() without arguments, it refreshes all non up to date projections.

-Regards,

 Sruthi

I tried to refresh the projections after restoration, which were all updated, but after using the select query, it did not return any rows. Is there a particular time I must refresh the projections?

Hi,

  You need to refresh it after creating the projection so that it can be used.

-Regards,

 Sruthi

It seems to be working once I refresh it. I will continue testing to see if anything else comes up. Thank you!

You need to refresh the Table after creating the Projection! It can solve this issue.

• Prashant Shekhar