SQL/MP Reference Manual

HP NonStop SQL/MP Reference Manual—523352-013
X-17
=_SQL_EXE_USE_SWAPVOL DEFINE
=_SQL_EXE_USE_SWAPVOL DEFINE
=_SQL_EXE_USE_SWAPVOL is a system DEFINE that directs SQL to allocate
temporary tables for serial plans on the swap volume for the process.
name
must be a legal Guardian file name but has no purpose except to make the ADD
DEFINE command syntactically correct.
Considerations—=_SQL_EXE_USE_SWAPVOL

You can use the =_SQL_EXE_USE_SWAPVOL DEFINE to change the location of
temporary tables from serial plans that might require more space than available on
the volumes where the temporary tables would normally be located, causing
file-system error 122.
NonStop SQL/MP normally places temporary tables on the same volume as the
outermost table in a join. For more information about temporary table placement,
see Temporary Tables on page T-4.

If SMF is installed on your node and the swap volume is a virtual volume, SQL
places temporary tables on the virtual volume when you specify
=_SQL_EXE_USE_SWAPVOL.

=_SQL_EXE_USE_SWAPVOL has no effect on the location of temporary tables
for parallel plans or on the SYNCDEPTH of temporary tables, both of which can
also lead to error 122.
Another DEFINE, =_SQL_TM_node_vol, allows you to redirect temporary tables
from both serial or parallel plans from a specific volume to another specific volume
and also allows you to specify SYNCDEPTH 1 instead of SYNCDEPTH 0 for the
temporary tables. If both DEFINEs exist, =_SQL_TM_node_vol overrides the
effect of =_SQL_EXE_USE_SWAPVOL for temporary files on the specified system
and volume.

Note that the kernel-managed swap facility manages process swap files.
Examples—=_SQL_EXE_USE_SWAPVOL

This TACL command directs SQL to allocate temporary tables for serial plans on
process swap volumes:
32> ADD DEFINE =_SQL_EXE_USE_SWAPVOL, FILE NOFILE

To direct SQL to resume allocating temporary tables at the normal location, delete
the DEFINE as shown:
34> DELETE DEFINE =_SQL_EXE_USE_SWAPVOL
ADD DEFINE =_SQL_EXE_USE_SWAPVOL, CLASS MAP, FILE name