Why are files opened in *DFTACTGRP?

Hi all, I'm a little stumped here. I'm debugging a program and when I
look at the job's open files (14. Display open files, if active) there are
files being opened in the *DFTACTGRP.

I'm calling an SQLRPGLE program and the program's Activation Group
Attribute is QILE. So my understanding is that files which are opened
will be in the QILE activation group (there are no OVRDBF in the job
stream and in fact only this program is called from the command line)

When the program breaks just before the sql statement the open files are
File Library Device Scope Activation Group
QDUI80 QSYS RROGB *ACTGRPDFN *DFTACTGRP 0000000000000002
QASQRESL QSYS2 QASQRESL *ACTGRPDFN *DFTACTGRP 0000000000000002
FA1120P TESTAM247 FA1120P *ACTGRPDFN QILE 0000000000000013
POSDAYP QS36F POSDAYP *ACTGRPDFN QILE 0000000000000013
DSTHSTP QS36F DSTHSTP *ACTGRPDFN QILE 0000000000000013
ROSHSTP TESTAM247 ROSHSTP *ACTGRPDFN QILE 0000000000000013
ROSHSTP TESTAM247 ROSHSTP *ACTGRPDFN QILE 0000000000000013
QDUI80 QSYS RROGB *ACTGRPDFN *DFTACTGRP 0000000000000002
QDDSPOF QSYS RROGB *ACTGRPDFN *DFTACTGRP 0000000000000002

This looks as I expect. But when I execute the following sql statement

Exec SQL
SELECT Min(a.FirstDate)
INTO :firstDate :firstDateNI
FROM (SELECT MIN(veendt) AS FirstDate
FROM posmvep
WHERE veitm# = :i_Item
AND vecus# = :i_Store
AND veendt >= :g_oldestdate80

UNION ALL

SELECT MIN(dhindt) AS FirstDate
FROM dsthstp
WHERE dhitm# = :i_Item
AND dhcus# = :i_Store
AND (dhwhid = 99
OR dhrel = 'Y')
// AND (dhtype <> 'O'
// AND dhtype <> 'P')
AND dhindt >= :g_oldestdate80

UNION ALL

SELECT DateToDecimalDate(MIN(rodate)) AS FirstDate
FROM roshstp
WHERE roitm# = :i_Item
AND rostr# = :i_Store
AND rodate >= :oldestdate) AS a;

the open files are
File Library Device Scope Activation Group
QDUI80 QSYS RROGB *ACTGRPDFN *DFTACTGRP 0000000000000002
QASQRESL QSYS2 QASQRESL *ACTGRPDFN *DFTACTGRP 0000000000000002
FA1120P TESTAM247 FA1120P *ACTGRPDFN QILE 0000000000000013
POSDAYP QS36F POSDAYP *ACTGRPDFN QILE 0000000000000013
DSTHSTP QS36F DSTHSTP *ACTGRPDFN QILE 0000000000000013
ROSHSTP TESTAM247 ROSHSTP *ACTGRPDFN QILE 0000000000000013
ROSHSTP TESTAM247 ROSHSTP *ACTGRPDFN QILE 0000000000000013
POSMVEP QS36F POSMVEP *ACTGRPDFN QILE 0000000000000013
DSTHSTP QS36F DSTHSTP *ACTGRPDFN *DFTACTGRP 0000000000000002
ROSHSTP TESTAM247 ROSHSTP *ACTGRPDFN *DFTACTGRP 0000000000000002
POSMVEL11 QS36F POSMVEL11 *ACTGRPDFN *DFTACTGRP 0000000000000002
DSTPALU1 QS36F DSTPALU1 *ACTGRPDFN *DFTACTGRP 0000000000000002
QDUI80 QSYS RROGB *ACTGRPDFN *DFTACTGRP 0000000000000002
QDDSPOF QSYS RROGB *ACTGRPDFN *DFTACTGRP 0000000000000002

I checked (15. Display file overrides, if active) and there are no
overrides.

Can someone explain why these new files show the *DFTACTGRP?

Thanks,

Rob