Execution Trace Information

When executing a query using the Administration tool, you can see a graphical representation of the execution trace of the query, by clicking the button View execution trace.

The following tables explain the meaning of the information provided by the trace:

Icons of the execution trace and their meaning

Icon

Meaning

image0

Flatten

image1

Group By

image2

Interface

image3

Intersection

image4

Join

image5

Minus

image6

Projection

image7

Selection

image8

Subquery

image9

Union

image10

Void. This branch of the execution plan has not been executed.

image11

Intermediate results were swapped to disk

image12

Data was obtained from the cache of the view.

image13

The node has additional information such as:

  • A function / operation cannot be delegated to the data source

  • The selection has not been executed because it contains incompatible conditions

image14

Route plan

image15

Virtual Plan: node that appears in the execution trace when the execution of a derived view is entirely pushed down to the data source.

image16

Root node of SELECT INTO queries. It indicates that the results of the query have been inserted in a materialized table (see section Materialized Tables of the VQL Guide)

image17

Data Movement. It indicates that the data obtained from a view has been “temporary” inserted into another data source. The section Data Movement explains the Data Movement optimization.

image18 and image19

JDBC data source and base view

image20 and image21

ODBC data source and base view

image22 and image23

Multidimensional data source

image24 and image25

Web service data source

image26 and image27

XML data source

image28 and image29

JSON data source

image30 and image31

DF data source

image32 and image33

WWW data source (ITPilot)

image34 and image35

LDAP data source

image38 and image39

Google Search data source

image40 and image41

BAPI data source (SAP ERP)

image42 and image43

Custom data source (Custom wrapper)

image44 and image45

Stored procedure

Color code of the nodes of the execution trace

Color code of the nodes of the execution trace

The following table lists the possible values of the attribute “State” of the nodes of a query’s execution trace.

Values of the “State” attribute of the nodes of a query’s execution trace

Status

Meaning

INIT

The query has started, but the node has not begun processing any result.

PROCESSING

The node is currently processing results generated by the nodes below.

STOPPED

The execution was cancelled by the user.

OK

The execution of the node finished correctly.

ERROR

There was an error during the execution of the query.

THREAD_TIMEOUT

The Server requested a thread to the Threads Pool, but the timeout was reached before obtaining one.

You can increase the timeout of the threads in the “Thread Pool” dialog of the “Administration > Server configuration” menu.

TOO_MANY_WORKS_TIMEOUT

The Server has reached the maximum number of threads.

You can increase the maximum number of threads in the “Thread Pool” dialog of the “Administration > Server configuration” menu.

PARSE_ERROR

There was an error while parsing the input data. E.g., the query involves a JSON base view and the input JSON document is not well formed.

INVALID_ROUTE

The connection details of the data source are not valid.

CONNECTION_ERROR

There was an error while trying to connect with the source. E.g., the view queries a Web service base view and the Web service server cannot be reached.

QUERY_TIMEOUT

The query reached the timeout.

All the clients of the Virtual DataPort server establish a timeout for the queries. That applies to clients that connect to Virtual DataPort via JDBC and ODBC and to the Administration Tool.

To change the query timeout of the Administration Tool, open the “Connection” tab of the “Tools > Admin Tool preferences” menu.

Read the sections “Access through JDBC” and “Access through ODBC” of the Developer Guide to know how to change the query timeout of JDBC or ODBC clients.

LICENSE_QUERY_TIMEOUT

The query reached the timeout set by the current license of the Denodo Platform.

ROW_LIMIT_REACHED

The execution finished correctly but not all the rows of the result set have been returned. That is because the query contains the LIMIT clause or the query has been executed from the “Execute view” dialog with the “Stop query when the limit is reached” check box selected.

ENOUGH_ROWS_RETRIEVED

The node was stopped because no more rows from this node were needed to complete the request.

INTERFACE_NOT_IMPLEMENTED

The query failed because the query involves an interface view that does not have an implementation view assigned.

INCOMPATIBLE_QUERY_VIEW

The node was not executed because the simplification engine detected that the selected query will not return results

CACHE_LOAD_ERROR

The cache load process finished with error