.. _pgagent_jobs:


*******************************
`Creating a pgAgent Job`:index:
*******************************

pgAgent is a scheduling agent that runs and manages jobs; each job consists of
steps and schedules.

To create or manage a job, use the pgAdmin tree control to browse to the server
on which the pgAgent database objects were created. The tree control will
display a *pgAgent Jobs* node, under which currently defined jobs are displayed.
To add a new job, right click on the *pgAgent Jobs* node, and select *Create
pgAgent Job...* from the context menu.

When the pgAgent dialog opens, use the tabs on the *pgAgent Job* dialog to
define the steps and schedule that make up a pgAgent job.

.. image:: images/pgagent_general.png
    :alt: pgAgent dialog general tab
    :align: center

Use the fields on the *General* tab to provide general information about a job:

* Provide a name for the job in the *Name* field.
* Move the *Enabled* switch to the *Yes* position to enable a job, or *No* to
  disable a job.
* Use the *Job Class* drop-down to select a class (for job categorization).
* Use the *Host Agent* field to specify the name of a machine that is running
  pgAgent to indicate that only that machine may execute the job.  Leave the
  field blank to specify that any machine may perform the job.

  .. note:: It is not always obvious what value to specify for the Host Agent
      in order to target a job step to a specific machine. With pgAgent running
      on the required machines and connected to the scheduler database, you can
      use the following query to view the hostnames as reported by each agent:

      .. code-block:: sql

          SELECT jagstation FROM pgagent.pga_jobagent

      Use the hostname exactly as reported by the query in the Host Agent
      field.
* Use the *Comment* field to store notes about the job.

.. image:: images/pgagent_steps.png
    :alt: pgAgent dialog steps tab
    :align: center

Use the *Steps* tab to define and manage the steps that the job will perform.
Click the Add icon (+) to add a new step; then click the compose icon (located
at the left side of the header) to open the step definition dialog:

.. image:: images/pgagent_step_definition.png
    :alt: pgAgent dialog definition tab
    :align: center

Use fields on the step definition dialog to define the step:

* Provide a name for the step in the *Name* field; please note that steps will
  be performed in alphanumeric order by name.
* Use the *Enabled* switch to include the step when executing the job (*True*)
  or to disable the step (*False*).
* Use the *Kind* switch to indicate if the job step invokes SQL code (*SQL*)
  or a batch script (*Batch*).

  * If you select *SQL*, use the *Code* tab to provide SQL code for the step.
  * If you select *Batch*, use the *Code* tab to provide the batch script that
    will be executed during the step.

.. note:: The fields *Connection type*, *Database* and *Connection string* are only
    applicable when *SQL* is selected because *Batch* cannot be run on remote servers.

* Use the *Connection type* switch to indicate if the step is performed on a
  local server (*Local*) or on a remote host (*Remote*).  If you specify a
  remote connection should be used for the step, the *Connection string* field
  will be enabled, and you must provide a libpq-style connection string.
* Use the *Database* drop-down to select the database on which the job step
  will be performed.
* Use the *Connection string* field to specify a libpq-style connection string
  to the remote server on which the step will be performed. For more information
  about writing a connection string, please see the
  `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq.html#libpq-connect>`_.
* Use the *On error* drop-down to specify the behavior of pgAgent if it
  encounters an error while executing the step.  Select from:

  * *Fail* - Stop the job if you encounter an error while processing this step.
  * *Success* - Mark the step as completing successfully, and continue.
  * *Ignore* - Ignore the error, and continue.

* Use the *Comment* field to provide a comment about the step.

.. image:: images/pgagent_step_definition_code.png
    :alt: pgAgent dialog step definition code tab
    :align: center

Use the context-sensitive field on the step definition dialog's *Code* tab to
provide the SQL code or batch script that will be executed during the step:

* If the step invokes SQL code, provide one or more SQL statements in the *SQL
  query* field.
* If the step performs a batch script, provide the script in the *Script* field.
  If you are running on a Windows server, standard batch file syntax must be
  used.  When running on a Linux server, any shell script may be used, provided
  that a suitable interpreter is specified on the first line (e.g. *#!/bin/sh*).

When you've provided all of the information required by the step, click the
compose icon to close the step definition dialog.  Click the add icon (+) to
add each additional step, or select the *Schedules* tab to define the job
schedule.

.. image:: images/pgagent_schedules.png
    :alt: pgAgent dialog schedules tab
    :align: center

Click the Add icon (+) to add a schedule for the job; then click the compose
icon (located at the left side of the header) to open the schedule definition
dialog:

.. image:: images/pgagent_schedule_definition.png
    :alt: pgAgent dialog schedules definition tab
    :align: center

Use the fields on the schedule definition tab to specify the days and times at
which the job will execute.

* Provide a name for the schedule in the *Name* field.
* Use the *Enabled* switch to indicate that pgAgent should use the schedule
  (*Yes*) or to disable the schedule (*No*).
* Use the calendar selector in the *Start* field to specify the starting date
  and time for the schedule.
* Use the calendar selector in the *End* field to specify the ending date and
  time for the schedule.
* Use the *Comment* field to provide a comment about the schedule.

Select the *Repeat* tab to define the days on which the schedule will execute.

.. image:: images/pgagent_schedule_repeat.png
    :alt: pgAgent dialog schedule repeat tab
    :align: center

Use the fields on the *Repeat* tab to specify the details about the schedule in
a cron-style format.  The job will execute on each date or time element selected
on the *Repeat* tab.

Click within a field to open a list of valid values for that field; click on a
specific value to add that value to the list of selected values for the field.
To clear the values from a field, click the X located at the right-side of the
field.

Use the fields within the *Days* box to specify the days on which the job will
execute:

* Use the *Week Days* field to select the days on which the job will execute.
* Use the *Month Days* field to select the numeric days on which the job will
  execute.  Specify the *Last Day* to indicate that the job should be performed
  on the last day of the month, irregardless of the date.
* Use the *Months* field to select the months in which the job will execute.

Use the fields within the *Times* box to specify the times at which the job will
execute:

* Use the *Hours* field to select the hour at which the job will execute.
* Use the *Minutes* field to select the minute at which the job will execute.

Select the *Exceptions* tab to specify any days on which the schedule will *not*
execute.

.. image:: images/pgagent_schedule_exceptions.png
    :alt: pgAgent dialog schedule exceptions tab
    :align: center

Use the fields on the *Exceptions* tab to specify days on which you wish the job
to not execute; for example, you may wish for jobs to not execute on national
holidays.

Click the Add icon (+) to add a row to the exception table, then:

* Click within the *Date* column to open a calendar selector, and select a date
  on which the job will not execute.    Specify *<Any>* in the *Date* column to
  indicate that the job should not execute on any day at the time selected.
* Click within the *Time* column to open a time selector, and specify a time on
  which the job will not execute.  Specify *<Any>* in the *Time* column to
  indicate that the job should not execute at any time on the day selected.

When you've finished defining the schedule, you can use the *SQL* tab to review
the code that will create or modify your job.

.. image:: images/pgagent_sql.png
    :alt: pgAgent dialog sql tab
    :align: center

Click the *Save* button to save the job definition, or *Close* to exit the job
without saving.  Use the *Reset* button to remove your unsaved entries from the
dialog.

After saving a job, the job will be listed under the *pgAgent Jobs* node of the
pgAdmin tree control of the server on which it was defined.  The *Properties*
tab in the main pgAdmin window will display a high-level overview of the
selected job, and the *Statistics* tab will show the details of each run of the
job.

.. image:: images/pgagent_properties.png
    :alt: pgAgent object properties
    :align: center

To modify an existing job or to review detailed information about a job,
right-click on a job name, and select *Properties* from the context menu.

