Describing Catalog Elements¶

The DESC statement allows obtaining a description of the elements in the Virtual DataPort server. Its syntax is given in Syntax of the statement DESC.

Syntax of the statement DESC¶

DESC QUERYPLAN <query>

DESC SESSION

DESC VQL ASSOCIATION <name:identifier with database>
    [ ( <DESC parameter> [, <DESC parameter> ]* ) ]

DESC VQL DATABASE [ <name:identifier> ]
    [ ( <DESC DATABASE parameters> [, <DESC DATABASE parameters> ]* ) ]

DESC VQL DATASOURCE <data source type> <name:identifier with database>
    [ ( <DESC parameter> [, <DESC parameter> ]* ) ]

DESC VQL FOLDER <path:literal>
    [ ( <DESC FOLDER parameter> [, <DESC FOLDER parameter> ]* ) ]

DESC VQL LISTENER JMS <name:identifier with database >
    [ ( <DESC parameter> [, <DESC parameter> ]* ) ]

DESC VQL MAP { I18N | SIMPLE } <name:identifier>
    [ ( <DESC parameter> [, <DESC parameter> ]* ) ]

DESC VQL PROCEDURE <name:identifier with database >
    [ ( <DESC parameter> [, <DESC parameter> ]* ) ]

DESC VQL TYPE <name:identifier with database>
    [ ( <DESC parameter> [, <DESC parameter> ]* ) ]

DESC VQL [ INTERFACE ] VIEW <name:identifier with database>
    [ ( <DESC parameter> [, <DESC parameter> ]* ) ]

DESC VQL VIEWSTATSUMMARY <view name:identifier with database>

DESC VQL { REST | SOAP } WEBSERVICE <name:identifier with database>
    [ FOR ( <operation or resource name:literal>
    [, <operation or resource name:literal>]* )]
    [ ( <DESC parameter> [, <DESC parameter> ]* ) ]

DESC VQL WIDGET <name:identifier with database >
    [ ( <DESC parameter> [, <DESC parameter> ]* ) ]

DESC VQL WRAPPER <wrapper type> <name:identifier with database>
    [ ( <DESC parameter> [, <DESC parameter> ]* ) ]

DESC VQL WRAPPER ITP [ <name:identifier with database> ]
    [ <ITPilot DESC parameter> ]

<data source type> ::=
    ARN | CUSTOM | DF | ESSBASE | GS | JDBC | JSON | LDAP | ODBC | OLAP
    | SAPBW | SAPBWBAPI | SAPERP | WS | XML }

<wrapper type> ::=
    <data source type>
  | ITP

<DESC FOLDER parameter> ::=
    'includeContents' = { 'yes' | 'no' }       // 'no' by default
  | <DESC parameter>

<DESC DATABASE parameters> ::=
  | 'includeEnvSpecificElements' = { 'yes' | 'no' }    // 'no' by default
  | 'includeNonEnvSpecificElements' = { 'yes' | 'no' } // 'no' by default
  | 'includeVCSConfiguration' = { 'yes' | 'no' }       // 'no' by default
  | <DESC parameter>
  | <ITPilot DESC parameter>

<DESC parameter> ::=
    'dropElements' = { 'yes' | 'no' }                  // 'yes' by default
  | 'replaceExistingElements' = { 'yes' | 'no' }       // 'no' by default
  | 'includeCreateDatabase' = { 'yes' | 'no' }         // 'no' by default
  | 'includeDependencies' = { 'yes' | 'no' }           // 'yes' by default
  | 'includeDeployments' = { 'yes' | 'no' }            // 'no' by default
  | 'includeJars' = { 'yes' | 'no' }                   // 'no' by default
  | 'includeStatistics' = { 'yes' | 'no' }             // 'no' by default
  | 'includeUserPrivileges' = { 'yes' | 'no' }         // 'no' by default
  | 'includeCreateWebService' = { 'yes' | 'no' }       // 'no' by default
  | 'includeProperties' = { 'yes' | 'no' }             // 'no' by default

<ITPilot DESC parameter> ::=
    'includeScanners' = { 'yes' | 'no' }               // 'no' by default
  | 'includeCustomComponents' = { 'yes' | 'no' }       // 'no' by default

<query> ::= (see Syntax of the SELECT statement)

DESC QUERYPLAN provides a look ahead at the execution plan that will be used to execute a query. Although it will be possible to access detailed trace information, including the execution plan used, after executing the query (see section TRACE Clause), the QUERYPLAN provides this information without having to run the query.

DESC SESSION returns the name of the database that the user is connected to, along with her login name.

The statements of the following group return the VQL of the elements of the catalog. If the element is a wrapper, a view, a Web service, a widget or an association, the statement also returns the statements needed to create the elements it depends on.

For example, DESC VQL VIEW V will return the statement required to create the view V and the statements needed to create the data types, wrappers, data sources, stored procedures and other views required to define the view V. If you are executing DESC VQL VIEW but you do not need the VQL statements of the elements that this view depends on, add the parameter includeDependencies.

E.g. DESC VQL VIEW V ('includeDependencies' = 'no') returns the sentence CREATE VIEW V ..., but not the sentences to creates the views that V depends on and its data sources.

The statement DESC VQL FOLDER returns the VQL statements to recreate the folder. If you add the option includeContents = yes, the output also includes the statements to recreate the elements inside the folder, including other folders. If you also add the option 'includeDependencies' = 'yes', the output also includes the statements to recreate the dependencies of the elements inside the folder.

For example, if there is a folder F1 with a view V in it, the command DESC VQL FOLDER F1 ('includeDependencies' = 'yes', 'includeContents' = 'yes') returns the statement to create the folder, the statements to create the view V and all the statements to create the elements that V depends on, even if they are in different folders.

To the DESC VQL WEBSERVICE you can add the token FOR followed by the name of one or more operations or resources. If you do this, the result will be an ALTER WEBSERVICE statement that will allow you to add these operations or resources to an existing web service.

With the parameter includeProperties = yes, the values of the parameters that depend on the environment are variables instead of the actual values. For example, with this property, in the CREATE DATASOURCE JDBC statements, the value of DATABASEURI will be something like ${databases.common_database.datasources.jdbc.oracle_product.DATABASEURI} instead of the URI of the database.

When you export a database with the option 'includeCreateDatabase'='yes', the output contains the statements CREATE DATABASE and ALTER DATABASE so the database is created with the same configuration, including the VCS settings of the database. If you do not want to export the VCS settings, add 'includeVCSConfiguration'='no'.

By default, the statistics of views are only included in the result when you export the VQL of the entire server, nor when you export a database nor when you export a view. To include the statistics of the views in the result, add the option 'includeStatistics'='yes'.

USER MANUALS

Describing Catalog Elements¶