QMF- Introduction

QMF (Query Management Facility) is IBM's interactive query and reporting tool for Db2 on z/OS. It lets you write SQL, run it, format the results into a readable report, save the work, and automate it — all from simple 3270 panels, without writing a program.

What QMF is

• QMF is an IBM licensed program product that sits on top of Db2 on z/OS (it also exists for other platforms, but this tutorial covers z/OS).
• It is a query tool, a report writer, and a small automation engine in one: you write SQL, see the answer rows, format them with a form, print them, or save them as a table.
• Everything you build in QMF — queries, forms, procedures — is stored as rows in Db2 tables in the QMF catalog, so objects are shared, secured, and backed up like any Db2 data.
• Typical users: business analysts who need ad-hoc answers, developers testing SQL before embedding it in programs, and operations staff running daily/weekly reports.

How QMF fits with Db2

• You must have a valid Db2 authorization ID and the needed SELECT/INSERT privileges; QMF does not bypass Db2 security — every query runs under your ID.
• QMF talks to Db2 through SQL just like any application, so the SQL you test in QMF behaves the same when moved into COBOL or PL/I programs.
• QMF ships with sample tables Q.STAFF and Q.ORG, which the examples in this tutorial use — most shops leave them installed for training.
• A QMF administrator can set governor limits (resource limits) that cap how many rows or how much time a query may use, protecting the system from runaway queries.

Starting QMF

• From any ISPF command line, type QMF and press Enter (the exact command name is set by your installation; some shops use a different name).
• From the TSO READY prompt you can also type QMF to start an interactive session.
• QMF can also run in batch mode under IKJEFT01 for scheduled reports — covered in Module 4.
• When QMF starts it connects to Db2 under your TSO user ID and shows the QMF home panel.

The QMF home panel

• The home panel is your starting point: it shows your saved objects grouped by type and gives you a command line for QMF commands.
• The object types shown are QUERY, DATA (saved tables), FORM, PROC, PROFILE, and ADM (administration, only if you are authorized).
• Typing LIST ALL on the command line shows every object you own; LIST QUERIES, LIST TABLES, LIST FORMS, and LIST PROCS narrow it to one type.
• From the home panel you can type a new SQL query directly, or DISPLAY an existing object to edit it.

The QMF panels you will use most

• SQL QUERY panel — where you type or edit SQL (or build a prompted query).
• REPORT panel — where query results are displayed after RUN QUERY.
• FORM panels — FORM.MAIN and friends, where you control headings, column widths, breaks, and totals.
• PROC panel — where you write a procedure: a saved list of QMF commands that run in order.
• PROFILE panel — your personal settings: PF keys, default printer, decimal format, and similar.

The four QMF objects

• Query — a saved SQL statement (or prompted query). Example: a query named Q1 that selects staff earning over 20000.
• Data — the rows a query returns, optionally saved permanently as a Db2 table with SAVE DATA.
• Form — the layout rules applied to the data: column headings, widths, edit codes, page headings, breaks, totals. FORM.MAIN is the default form QMF applies.
• Proc — a saved sequence of QMF commands, for example RUN QUERY, PRINT REPORT, SAVE DATA — QMF's way of automating a job.

A first taste: commands you will learn

• RUN QUERY runs a query and shows the REPORT panel with the answer rows.
• SAVE QUERY stores your SQL in the database so you can reuse it.
• PRINT REPORT sends the formatted report to a printer or data set.
• SAVE DATA turns the answer rows into a real Db2 table.
• RUN PROC executes a saved procedure — the building block of scheduled reporting.