Add binary compatibility testing.

We need some tests to see if binaries can be swapped around. This
commit provides a simple framework and basic tests to check if
binaries can be upgraded/downgraded by just swapping the Greenplum
binary install paths. Running the tests requires the user to have
another Greenplum compiled which will be provided as an argument to
the test script. It also requires the regression database to be built
from running tests in src/test/regress.

src/test/binary_swap/.gitignore

+results
+regression.out
+regression.diffs
+dump_current.sql
+dump_other.sql

src/test/binary_swap/expected/diff_dumps.out

+\! diff dump_other.sql dump_current.sql

src/test/binary_swap/expected/gpcheckcat.out

+-- start_ignore
+\! gpcheckcat binary_swap
+-- end_ignore
+\! echo $?
+0

src/test/binary_swap/expected/inserts.out

+\c regression
+-- Insert into tables generated from src/test/regress
+-- Following tables from freeze_aux_tables:
+INSERT INTO test_table_heap_with_toast SELECT i, i*2, i*5 FROM generate_series(1, 20)i;
+INSERT INTO test_table_ao_with_toast SELECT * FROM test_table_heap_with_toast;
+INSERT INTO test_table_co_with_toast SELECT * FROM test_table_heap_with_toast;

src/test/binary_swap/expected/pg_dumpall_current.out

+\! pg_dumpall -f dump_current.sql
+\! echo $?
+0

src/test/binary_swap/expected/pg_dumpall_other.out

+\! pg_dumpall -f dump_other.sql
+\! echo $?
+0

src/test/binary_swap/schedule1

+test: pg_dumpall_current
+test: gpcheckcat

src/test/binary_swap/schedule2

+test: pg_dumpall_other
+test: diff_dumps
+test: inserts
+test: pg_dumpall_other
+test: gpcheckcat

src/test/binary_swap/schedule3

+test: pg_dumpall_current
+test: diff_dumps
+test: inserts
+test: pg_dumpall_current
+test: gpcheckcat

src/test/binary_swap/sql/diff_dumps.sql

+\! diff dump_other.sql dump_current.sql

src/test/binary_swap/sql/gpcheckcat.sql

+-- start_ignore
+\! gpcheckcat binary_swap
+-- end_ignore
+
+\! echo $?

src/test/binary_swap/sql/inserts.sql

+\c regression
+
+-- Insert into tables generated from src/test/regress
+-- Following tables from freeze_aux_tables:
+INSERT INTO test_table_heap_with_toast SELECT i, i*2, i*5 FROM generate_series(1, 20)i;
+INSERT INTO test_table_ao_with_toast SELECT * FROM test_table_heap_with_toast;
+INSERT INTO test_table_co_with_toast SELECT * FROM test_table_heap_with_toast;

src/test/binary_swap/sql/pg_dumpall_current.sql

+\! pg_dumpall -f dump_current.sql
+\! echo $?

src/test/binary_swap/sql/pg_dumpall_other.sql

+\! pg_dumpall -f dump_other.sql
+\! echo $?

src/test/binary_swap/test_binary_swap.sh

+#! /bin/bash
+
+## ==================================================================
+## Required: regression database generated from src/test/regress
+##
+## Test binary swap from current Greenplum install to another
+## Greenplum install. The flow goes like this:
+##   1. Run pg_dumpall on current database
+##   2. Start binaries provided by -b (required)
+##   3. Run pg_dumpall on other binary and diff dumps
+##   4. Run some inserts and do another pg_dumpall
+##   5. Start binaries provided by -c (default current $GPHOME).
+##   6. Run pg_dumpall on current binary and diff dumps
+##   7. Run some more inserts and run another pg_dumpall
+##
+## Providing the binaries can be interchangeable between -b and -c
+## but technically shouldn't matter. However, the binary provided in
+## -c will be the active binary at the end of the run.
+## ==================================================================
+
+## Clean previous generated test output
+clean_output()
+{
+    rm -rf results
+    rm -f dump_current.sql dump_other.sql
+}
+
+## Run tests via pg_regress with given schedule name
+run_tests()
+{
+    SCHEDULE_NAME=$1
+    ../regress/pg_regress --dbname=binswap_connect --init-file=../regress/init_file --schedule=${SCHEDULE_NAME}
+    if [ $? != 0 ]; then
+        exit 1
+    fi
+}
+
+##  Start up a Greenplum binary using same $MASTER_DATA_DIRECTORY
+start_binary()
+{
+    BINARY_PATH=$1
+    gpstop -ai
+    source $BINARY_PATH/greenplum_path.sh
+    gpstart -a
+    echo "Select our Greenplum version just to be sure..."
+    psql -c "select version()" postgres
+}
+
+usage()
+{
+    appname=`basename $0`
+    echo "$appname usage:"
+    echo " -b <dir>   Greenplum install path for another binary to test upgrade/downgrade from (Required User Input)"
+    echo " -c <dir>   Greenplum install path for current binary to test upgrade/downgrade to (Default: \$GPHOME)"
+    echo " -m <dir>   Greenplum Master Data Directory (Default: \$MASTER_DATA_DIRECTORY)"
+    echo " -p <port>  Greenplum Master Port (Default: \$PGPORT)"
+    exit 0
+}
+
+while getopts ":c:b:m:p" opt; do
+    case ${opt} in
+        c)
+            GPHOME_CURRENT=$OPTARG
+            ;;
+        b)
+            GPHOME_OTHER=$OPTARG
+            ;;
+        m)
+            MDD_CURRENT=$OPTARG
+            ;;
+        p)
+            PGPORT_CURRENT=$OPTARG
+            ;;
+        *)
+            usage
+            ;;
+    esac
+done
+
+## Main script
+## ==================================================
+
+## Argument checking
+GPHOME_CURRENT=${GPHOME_CURRENT:=$GPHOME}
+MDD_CURRENT=${MDD_CURRENT:=$MASTER_DATA_DIRECTORY}
+PGPORT_CURRENT=${PGPORT_CURRENT:=$PGPORT}
+
+if [ "${GPHOME_OTHER}x" == "x" ] || ! [ -f $GPHOME_OTHER/greenplum_path.sh ]; then
+    echo "Use -b to provide a valid Greenplum install path to upgrade/downgrade from"
+    exit 1
+fi
+
+if [ "${GPHOME_CURRENT}x" == "x" ] || ! [ -f $GPHOME_CURRENT/greenplum_path.sh ]; then
+    echo "Use -c to provide a valid Greenplum install path to upgrade/downgrade to (Default: \$GPHOME)"
+    exit 1
+fi
+
+if [ "${MDD_CURRENT}x" == "x" ]; then
+    echo "Use -m to provide a valid Greenplum Master Data Directory (Default: \$MASTER_DATA_DIRECTORY)"
+    exit 1
+fi
+
+if [ "${PGPORT_CURRENT}x" == "x" ]; then
+    echo "Use -p to provide a valid Greenplum Master Port (Default: \$PGPORT)"
+    exit 1
+fi
+
+## Grab the Greenplum versions of each binary for display
+CURRENT_VERSION=`$GPHOME_CURRENT/bin/gpstart --version | awk '{ for (i=3; i<NF; i++) printf $i " "; print $NF }'`
+OTHER_VERSION=`$GPHOME_OTHER/bin/gpstart --version | awk '{ for (i=3; i<NF; i++) printf $i " "; print $NF }'`
+
+echo "Binary Swap tests"
+echo "=================================================="
+echo "Current binaries: ${CURRENT_VERSION}"
+echo "                  ${GPHOME_CURRENT}"
+echo "  Other binaries: ${OTHER_VERSION}"
+echo "                  ${GPHOME_OTHER}"
+echo "=================================================="
+
+## Clean our directory of any previous test output
+clean_output
+
+## Start/restart current Greenplum and do initial dump to compare against
+start_binary $GPHOME_CURRENT
+run_tests schedule1
+
+## Change the binary, dump, and then compare the two dumps generated by
+## both binaries. Then we do some inserts and dump again.
+start_binary $GPHOME_OTHER
+run_tests schedule2
+
+## Change the binary back, dump, and then compare the two new dumps
+## generated by both binaries. Then we do some inserts and check to see
+## if dump still works fine.
+start_binary $GPHOME_CURRENT
+run_tests schedule3
+
+## Print unnecessary success output
+echo "SUCCESS! Provided binaries are swappable."