Add script that runs the regression tests with all valid

combinations of query-plan-type backend options.  Good for testing
planner/optimizer.  Tedious, though.

src/test/regress/regressplans.sh

+#! /bin/sh
+
+# This script runs the Postgres regression tests with all useful combinations
+# of the backend options that disable various query plan types.  If the
+# results are not all the same, it may indicate a bug in a particular
+# plan type, or perhaps just a regression test whose results aren't fully
+# determinate (eg, due to lack of an ORDER BY keyword).
+#
+# Run this in the src/test/regress directory, after doing the usual setup
+# for a regular regression test, ie, "make clean all" (you should be ready
+# to do "make runtest").
+#
+# The backend option switches that we use here are:
+#	-fs	disable sequential scans
+#	-fi	disable index scans
+#	-fn	disable nestloop joins
+#	-fm	disable merge joins
+#	-fh	disable hash joins
+# Only mergejoin and hashjoin are really guaranteed to turn off; the others
+# just bias the optimizer's cost calculations heavily against that choice.
+# There's no point in trying to turn off both scan types or all three join
+# types simultaneously; ergo, we have 3*7 = 21 interesting combinations.
+#
+# Note that this will take *more than* 21 times longer than a regular
+# regression test, since we are preventing the system from using the most
+# efficient available query plans!  Have patience.
+
+
+# Select make to use --- default gmake, can be overridden by env var
+MAKE=${MAKE:-gmake}
+
+mkdir planregress
+
+PGOPTIONS="                   " $MAKE runtest
+mv -f regress.out planregress/out.normal
+mv -f regression.diffs planregress/diffs.normal
+PGOPTIONS="                -fh" $MAKE runtest
+mv -f regress.out planregress/out.h
+mv -f regression.diffs planregress/diffs.h
+PGOPTIONS="            -fm    " $MAKE runtest
+mv -f regress.out planregress/out.m
+mv -f regression.diffs planregress/diffs.m
+PGOPTIONS="            -fm -fh" $MAKE runtest
+mv -f regress.out planregress/out.mh
+mv -f regression.diffs planregress/diffs.mh
+PGOPTIONS="        -fn        " $MAKE runtest
+mv -f regress.out planregress/out.n
+mv -f regression.diffs planregress/diffs.n
+PGOPTIONS="        -fn     -fh" $MAKE runtest
+mv -f regress.out planregress/out.nh
+mv -f regression.diffs planregress/diffs.nh
+PGOPTIONS="        -fn -fm    " $MAKE runtest
+mv -f regress.out planregress/out.nm
+mv -f regression.diffs planregress/diffs.nm
+PGOPTIONS="    -fi            " $MAKE runtest
+mv -f regress.out planregress/out.i
+mv -f regression.diffs planregress/diffs.i
+PGOPTIONS="    -fi         -fh" $MAKE runtest
+mv -f regress.out planregress/out.ih
+mv -f regression.diffs planregress/diffs.ih
+PGOPTIONS="    -fi     -fm    " $MAKE runtest
+mv -f regress.out planregress/out.im
+mv -f regression.diffs planregress/diffs.im
+PGOPTIONS="    -fi     -fm -fh" $MAKE runtest
+mv -f regress.out planregress/out.imh
+mv -f regression.diffs planregress/diffs.imh
+PGOPTIONS="    -fi -fn        " $MAKE runtest
+mv -f regress.out planregress/out.in
+mv -f regression.diffs planregress/diffs.in
+PGOPTIONS="    -fi -fn     -fh" $MAKE runtest
+mv -f regress.out planregress/out.inh
+mv -f regression.diffsregression.planregress/inh
+PGOPTIONS="    -fi -fn -fm    " $MAKE runtest
+mv -f regress.out planregress/out.inm
+mv -f regression.diffs planregress/diffs.inm
+PGOPTIONS="-fs                " $MAKE runtest
+mv -f regress.out planregress/out.s
+mv -f regression.diffs planregress/diffs.s
+PGOPTIONS="-fs             -fh" $MAKE runtest
+mv -f regress.out planregress/out.sh
+mv -f regression.diffs planregress/diffs.sh
+PGOPTIONS="-fs         -fm    " $MAKE runtest
+mv -f regress.out planregress/out.sm
+mv -f regression.diffs planregress/diffs.sm
+PGOPTIONS="-fs         -fm -fh" $MAKE runtest
+mv -f regress.out planregress/out.smh
+mv -f regression.diffs planregress/diffs.smh
+PGOPTIONS="-fs     -fn        " $MAKE runtest
+mv -f regress.out planregress/out.sn
+mv -f regression.diffs planregress/diffs.sn
+PGOPTIONS="-fs     -fn     -fh" $MAKE runtest
+mv -f regress.out planregress/out.snh
+mv -f regression.diffs planregress/diffs.snh
+PGOPTIONS="-fs     -fn -fm    " $MAKE runtest
+mv -f regress.out planregress/out.snm
+mv -f regression.diffs planregress/diffs.snm
+
+exit 0