QueryMonitor

The QueryMonitor logs queries executed at CData Virtuality, except queries that include only system tables or views.

A query can be in one of the following states:

States available for active queries:

State

Description

PARSING

The query runs in the CData Virtuality Server, generating the query plan. Queries are not sent to the data sources yet.

The duration of this state is usually relatively short

RUNNING

The CData Virtuality Server is getting data from the sources. The query is running on the sources now.

The duration of this state depends on the kind of query

FETCHING All the data is in the CData Virtuality Server, but there are still open cursors (e.g. an SQL Editor tab in the CData Virtuality Studio is open and shows the result of the query), and so the request is, from a technical point of view, also still open

States available for finished queries:

State

Description

SUCCESS All the data is in the CData Virtuality Server, no cursors are open, and the request is closed

FAILED

An error occurred at some point.

Please note that a query is marked as failed only if a problem occurs before the FETCHING state

INTERRUPTED

The request has been cancelled at some point.

This state will be set in one of the two cases:

The user cancels the request (e.g., using the killQuery() procedure). Please note that it is impossible to kill a query while in the FETCHING state. The failureReason field will show the message "Query interrupted: request cancelled by the user";
The server is restarted and all queries in the PARSING | RUNNING | FETCHING state are reset to INTERRUPTED. "Finished time" for such queries will be set to the server restart time. The failureReason field will show the message "Query interrupted: DVServer has been restarted. Previous state: <PARSING | RUNNING | FETCHING>