Redshift: stv_inflight and stv_recents showing conflicting results

Question

As per documentation,

To determine what queries are currently running against the database, type the following query:

select user_name, db_name, pid, query
from stv_recents
where status = 'Running';

Also, as per documentation,

To view all active queries currently running on the database, type the following query:

select * from stv_inflight;

However, i have observed that the two resultset doesn't match sometime. Right now, there were some SELECT queries which were aborted from the client and are not showing in the stv_inflight table but they are being shown in the stv_recents table with a Running status.

Can anybody explain why this is happening?

P.S. The queries involves user defined table.

Answer 1

From the documentation on the Redshift System Tables and Views,

STV views are virtual views that contain snapshots of the current system data. They are based on transient in-memory data and are not persisted to disk-based logs or regular tables.

Further, the documentation explains with the following contradictory example.

the following query against a system table might well return rows

select * from stv_exec_state
where currenttime > (select max(currenttime) from stv_exec_state)

So, over all if you are running queries against STV tables, the responses that you get will be based on the instantaneous state of the in-memory system data structures, and the responses of two subsequent queries may very well be not correlatable.