Change PAX Plugin to Be Disabled by Default

Currently, the PAX is enabled by default in configure, and users need
to explicitly disable it via `--disable-pax` option. However, this
behavior is inconsistent with most of the other extensions under the
contrib/ or gpcontrib/ dir, which are typically disabled by default
unless explicitly enabled.

PAX currently requires downloading several submodules during the build,
for users without prior knowledge, this will lead to build failures.

This PR is to change the default behavior of PAX to disabled, which will
be more user-friendly for users.

See: https://lists.apache.org/thread/q1n7hztzzydk1owhn73tc1b4chyhzx85

Author: tuhaihe

configure

@@ -570,6 +570,7 @@ ac_hostname=`(hostname || uname -n) 2>/dev/null | sed 1q`
 #
 # Initializations.
 #
+ac_default_prefix=/usr/local
 ac_clean_files=
 ac_config_libobj_dir=.
 LIBOBJS=
@@ -759,8 +760,8 @@ HAVE_CXX14
 enable_gpcloud
 enable_shared_postgres_backend
 enable_mapreduce
-enable_catalog_ext
 enable_serverless
+enable_catalog_ext
 enable_orca
 autodepend
 PKG_CONFIG_LIBDIR
@@ -1608,7 +1609,7 @@ Optional Features:
   --enable-cassert        enable assertion checks (for debugging)
   --disable-orca          disable ORCA optimizer
   --enable-catalog-ext    enable Cloudberry catalog extension
-  --enable-serverless     enable Cloudberry serverless mode
+  --enable-serverless     use serverless mode of Cloudberry
   --enable-mapreduce      enable Cloudberry Mapreduce support
   --disable-shared-postgres-backend
                           enable Cloudberry shared postgres backend support
@@ -1618,7 +1619,7 @@ Optional Features:
                           library)
   --disable-preload-ic-module
                           disable preload interconnect module
-  --enable-pax            enable pax support
+  --enable-pax            enable PAX support
   --disable-thread-safety disable thread-safety in client libraries
   --enable-openssl-redirect
                           enable redirect openssl interface to internal
@@ -8380,7 +8381,7 @@ $as_echo "checking whether to build with catalog extension... $enable_catalog_ex
 
 
 #
-# Enable serverless mode
+# --enable-serverless uses serverless mode of Cloudberry
 #
 
 
@@ -8407,8 +8408,8 @@ else
 fi
 
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: checking whether to use serverless architecture of Cloudberry ... $enable_serverless" >&5
-$as_echo "checking whether to use serverless architecture of Cloudberry ... $enable_serverless" >&6; }
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: checking whether to use serverless mode of Cloudberry... $enable_serverless" >&5
+$as_echo "checking whether to use serverless mode of Cloudberry... $enable_serverless" >&6; }
 
 
 #
@@ -9101,6 +9102,7 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: checking whether to build with preload ic module ... $enable_preload_ic_module" >&5
 $as_echo "checking whether to build with preload ic module ... $enable_preload_ic_module" >&6; }
 
+
 #
 # pax support
 #
@@ -9124,13 +9126,14 @@ $as_echo "#define USE_PAX_STORAGE 1" >>confdefs.h
   esac
 
 else
-  enable_pax=yes
-  
-  $as_echo "#define USE_PAX_STORAGE 1" >>confdefs.h
+  enable_pax=no
+
 fi
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: checking whether to build with pax support ... $enable_pax" >&5
-$as_echo "checking whether to build with pax support ... $enable_pax" >&6; }
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: checking whether to build with PAX support ... $enable_pax" >&5
+$as_echo "checking whether to build with PAX support ... $enable_pax" >&6; }
+
 
 #
 # Include directories

configure.ac

@@ -928,8 +928,8 @@ AC_SUBST(enable_preload_ic_module)
 #
 # pax support
 #
-PGAC_ARG_BOOL(enable, pax, yes,
-              [disable PAX support],
+PGAC_ARG_BOOL(enable, pax, no,
+              [enable PAX support],
               [AC_DEFINE(USE_PAX_STORAGE, 1,
                          [Define to 1 to support PAX])])
 AC_MSG_RESULT([checking whether to build with PAX support ... $enable_pax])