---
layout: article
title: MPE_DERIVED
description: The MPE_DERIVED table is used to configure computed columns that appear in the EDIT screen and can be filtered on without being stored in the table.
---

# MPE_DERIVED

The MPE_DERIVED table is used to configure derived (computed) variables - columns that are created when a table is loaded into the EDIT screen, so that they can be displayed and filtered on without being stored.  More details are available in the [user guide](/derived-variables/)

The table is itself registered in [MPE_TABLES](/tables/mpe_tables/), so it is maintained through the EDIT screen with the usual review and approve workflow.

## Columns

 - `TX_FROM num`: SCD2 open datetime
 - 🔑 `TX_TO num`: SCD2 close datetime
 - 🔑 `LIBREF char(8)`: The libref of the target table
 - 🔑 `DSN char(32)`: The target table
 - 🔑 `VARIABLE_NM char(32)`: The name of the derived column
 - `VARIABLE_TYPE char(1)`: `C` for character, `N` for numeric
 - `VARIABLE_LENGTH num`: Character length, or numeric length (1-8)
 - `VARIABLE_FORMAT char(32)`: Optional SAS format, eg `DATE9.`
 - `VARIABLE_LOGIC char(4000)`: The SAS expression that produces the value
 - `ACTIVE num`: Set to 1 to apply the variable