Configuration
    The first step of the installation procedure is to configure the
    source tree for your system and choose the options you would like.
    This is done by running the configure script. For a
    default installation simply enter:
./configure
This script will run a number of tests to determine values for various system dependent variables and detect any quirks of your operating system, and finally will create several files in the build tree to record what it found.
    You can also run configure in a directory outside
    the source tree, and then build there, if you want to keep the build
    directory separate from the original source files.  This procedure is
    called a
    VPATH
    build.  Here's how:
mkdir build_dircd build_dir/path/to/source/tree/configure [options go here]make
    The default configuration will build the server and utilities, as
    well as all client applications and interfaces that require only a
    C compiler. All files will be installed under
    /usr/local/pgsql by default.
   
    You can customize the build and installation process by supplying one
    or more command line options to configure.
    Typically you would customize the install location, or the set of
    optional features that are built.  configure
    has a large number of options, which are described in
    Section 17.4.1.
   
    Also, configure responds to certain environment
    variables, as described in Section 17.4.2.
    These provide additional ways to customize the configuration.
   
Build
To start the build, type either of:
makemake all
(Remember to use GNU make.) The build will take a few minutes depending on your hardware.
   If you want to build everything that can be built, including the
   documentation (HTML and man pages), and the additional modules
   (contrib), type instead:
make world
   If you want to build everything that can be built, including the
   additional modules (contrib), but without
   the documentation, type instead:
make world-bin
    If you want to invoke the build from another makefile rather than
    manually, you must unset MAKELEVEL or set it to zero,
    for instance like this:
build-postgresql:
        $(MAKE) -C postgresql MAKELEVEL=0 all
Failure to do that can lead to strange error messages, typically about missing header files.
Regression Tests
If you want to test the newly built server before you install it, you can run the regression tests at this point. The regression tests are a test suite to verify that PostgreSQL runs on your machine in the way the developers expected it to. Type:
make check
(This won't work as root; do it as an unprivileged user.) See Chapter 33 for detailed information about interpreting the test results. You can repeat this test at any later time by issuing the same command.
Installing the Files
If you are upgrading an existing system be sure to read Section 19.6, which has instructions about upgrading a cluster.
To install PostgreSQL enter:
make install
This will install files into the directories that were specified in Step 1. Make sure that you have appropriate permissions to write into that area. Normally you need to do this step as root. Alternatively, you can create the target directories in advance and arrange for appropriate permissions to be granted.
To install the documentation (HTML and man pages), enter:
make install-docs
If you built the world above, type instead:
make install-world
This also installs the documentation.
If you built the world without the documentation above, type instead:
make install-world-bin
    You can use make install-strip instead of
    make install to strip the executable files and
    libraries as they are installed.  This will save some space.  If
    you built with debugging support, stripping will effectively
    remove the debugging support, so it should only be done if
    debugging is no longer needed.  install-strip
    tries to do a reasonable job saving space, but it does not have
    perfect knowledge of how to strip every unneeded byte from an
    executable file, so if you want to save all the disk space you
    possibly can, you will have to do manual work.
   
The standard installation provides all the header files needed for client application development as well as for server-side program development, such as custom functions or data types written in C.
Client-only installation: If you want to install only the client applications and interface libraries, then you can use these commands:
make -C src/bin installmake -C src/include installmake -C src/interfaces installmake -C doc install
    src/bin has a few binaries for server-only use,
    but they are small.
    
Uninstallation: 
    To undo the installation use the command make
    uninstall. However, this will not remove any created directories.
   
Cleaning: 
    After the installation you can free disk space by removing the built
    files from the source tree with the command make
    clean. This will preserve the files made by the configure
    program, so that you can rebuild everything with make
    later on. To reset the source tree to the state in which it was
    distributed, use make distclean. If you are going to
    build for several platforms within the same source tree you must do
    this and re-configure for each platform.  (Alternatively, use
    a separate build tree for each platform, so that the source tree
    remains unmodified.)
   
   If you perform a build and then discover that your configure
   options were wrong, or if you change anything that configure
   investigates (for example, software upgrades), then it's a good
   idea to do make distclean before reconfiguring and
   rebuilding.  Without this, your changes in configuration choices
   might not propagate everywhere they need to.
  
configure Options
    configure's command line options are explained below.
    This list is not exhaustive (use ./configure --help
    to get one that is).  The options not covered here are meant for
    advanced use-cases such as cross-compilation, and are documented in
    the standard Autoconf documentation.
   
      These options control where make install will put
      the files.  The --prefix option is sufficient for
      most cases.  If you have special needs, you can customize the
      installation subdirectories with the other options described in this
      section.  Beware however that changing the relative locations of the
      different subdirectories may render the installation non-relocatable,
      meaning you won't be able to move it after installation.
      (The man and doc locations are
      not affected by this restriction.)  For relocatable installs, you
      might want to use the --disable-rpath option
      described later.
     
--prefix=PREFIX
         Install all files under the directory PREFIX
         instead of /usr/local/pgsql. The actual
         files will be installed into various subdirectories; no files
         will ever be installed directly into the
         PREFIX directory.
        
--exec-prefix=EXEC-PREFIX
         You can install architecture-dependent files under a
         different prefix, EXEC-PREFIX, than what
         PREFIX was set to. This can be useful to
         share architecture-independent files between hosts. If you
         omit this, then EXEC-PREFIX is set equal to
         PREFIX and both architecture-dependent and
         independent files will be installed under the same tree,
         which is probably what you want.
        
--bindir=DIRECTORY
         Specifies the directory for executable programs. The default
         is EXEC-PREFIX/bin/usr/local/pgsql/bin.
        
--sysconfdir=DIRECTORY
         Sets the directory for various configuration files,
         PREFIX/etc
--libdir=DIRECTORY
         Sets the location to install libraries and dynamically loadable
         modules. The default is
         EXEC-PREFIX/lib
--includedir=DIRECTORY
         Sets the directory for installing C and C++ header files. The
         default is PREFIX/include
--datarootdir=DIRECTORY
         Sets the root directory for various types of read-only data
         files.  This only sets the default for some of the following
         options.  The default is
         PREFIX/share
--datadir=DIRECTORY
         Sets the directory for read-only data files used by the
         installed programs. The default is
         DATAROOTDIR
--localedir=DIRECTORY
         Sets the directory for installing locale data, in particular
         message translation catalog files.  The default is
         DATAROOTDIR/locale
--mandir=DIRECTORY
         The man pages that come with PostgreSQL will be installed under
         this directory, in their respective
         man subdirectories.
         The default is xDATAROOTDIR/man
--docdir=DIRECTORY
         Sets the root directory for installing documentation files,
         except “man” pages.  This only sets the default for
         the following options.  The default value for this option is
         DATAROOTDIR/doc/postgresql
--htmldir=DIRECTORY
         The HTML-formatted documentation for
         PostgreSQL will be installed under
         this directory.  The default is
         DATAROOTDIR
       Care has been taken to make it possible to install
       PostgreSQL into shared installation locations
       (such as /usr/local/include) without
       interfering with the namespace of the rest of the system. First,
       the string “/postgresql” is
       automatically appended to datadir,
       sysconfdir, and docdir,
       unless the fully expanded directory name already contains the
       string “postgres” or
       “pgsql”. For example, if you choose
       /usr/local as prefix, the documentation will
       be installed in /usr/local/doc/postgresql,
       but if the prefix is /opt/postgres, then it
       will be in /opt/postgres/doc. The public C
       header files of the client interfaces are installed into
       includedir and are namespace-clean. The
       internal header files and the server header files are installed
       into private directories under includedir. See
       the documentation of each interface for information about how to
       access its header files. Finally, a private subdirectory will
       also be created, if appropriate, under libdir
       for dynamically loadable modules.
      
The options described in this section enable building of various PostgreSQL features that are not built by default. Most of these are non-default only because they require additional software, as described in Section 17.2.
--enable-nls[=LANGUAGES]
         Enables Native Language Support (NLS),
         that is, the ability to display a program's messages in a
         language other than English.
         LANGUAGES is an optional space-separated
         list of codes of the languages that you want supported, for
         example --enable-nls='de fr'.  (The intersection
         between your list and the set of actually provided
         translations will be computed automatically.)  If you do not
         specify a list, then all available translations are
         installed.
        
To use this option, you will need an implementation of the Gettext API.
--with-perlBuild the PL/Perl server-side language.
--with-pythonBuild the PL/Python server-side language.
--with-tclBuild the PL/Tcl server-side language.
--with-tclconfig=DIRECTORY
         Tcl installs the file tclConfig.sh, which
         contains configuration information needed to build modules
         interfacing to Tcl. This file is normally found automatically
         at a well-known location, but if you want to use a different
         version of Tcl you can specify the directory in which to look
         for tclConfig.sh.
        
--with-icuBuild with support for the ICU library, enabling use of ICU collation features (see Section 24.2). This requires the ICU4C package to be installed. The minimum required version of ICU4C is currently 4.2.
         By default,
         pkg-config
         will be used to find the required compilation options.  This is
         supported for ICU4C version 4.6 and later.
         For older versions, or if pkg-config is
         not available, the variables ICU_CFLAGS
         and ICU_LIBS can be specified
         to configure, like in this example:
./configure ... --with-icu ICU_CFLAGS='-I/some/where/include' ICU_LIBS='-L/some/where/lib -licui18n -licuuc -licudata'
         (If ICU4C is in the default search path
         for the compiler, then you still need to specify nonempty strings in
         order to avoid use of pkg-config, for
         example, ICU_CFLAGS=' '.)
        
--with-llvmBuild with support for LLVM based JIT compilation (see Chapter 32). This requires the LLVM library to be installed. The minimum required version of LLVM is currently 3.9.
         llvm-config
         will be used to find the required compilation options.
         llvm-config, and then
         llvm-config-$major-$minor for all supported
         versions, will be searched for in your PATH.  If
         that would not yield the desired program,
         use LLVM_CONFIG to specify a path to the
         correct llvm-config. For example
./configure ... --with-llvm LLVM_CONFIG='/path/to/llvm/bin/llvm-config'
         LLVM support requires a compatible
         clang compiler (specified, if necessary, using the
         CLANG environment variable), and a working C++
         compiler (specified, if necessary, using the CXX
         environment variable).
        
--with-lz4Build with LZ4 compression support. This allows the use of LZ4 for compression of table data.
--with-ssl=LIBRARY
       
       
         Build with support for SSL (encrypted)
         connections. The only LIBRARY
         supported is openssl. This requires the
         OpenSSL package to be installed.
         configure will check for the required
         header files and libraries to make sure that your
         OpenSSL installation is sufficient
         before proceeding.
        
--with-openssl
         Obsolete equivalent of --with-ssl=openssl.
        
--with-gssapi
         Build with support for GSSAPI authentication. On many systems, the
         GSSAPI system (usually a part of the Kerberos installation) is not
         installed in a location
         that is searched by default (e.g., /usr/include,
         /usr/lib), so you must use the options
         --with-includes and --with-libraries in
         addition to this option.  configure will check
         for the required header files and libraries to make sure that
         your GSSAPI installation is sufficient before proceeding.
        
--with-ldap
         Build with LDAP
         support for authentication and connection parameter lookup (see
         Section 34.18 and
         Section 21.10 for more information). On Unix,
         this requires the OpenLDAP package to be
         installed. On Windows, the default WinLDAP
         library is used.  configure will check for the required
         header files and libraries to make sure that your
         OpenLDAP installation is sufficient before
         proceeding.
        
--with-pam--with-bsd-authBuild with BSD Authentication support. (The BSD Authentication framework is currently only available on OpenBSD.)
--with-systemdBuild with support for systemd service notifications. This improves integration if the server is started under systemd but has no impact otherwise; see Section 19.3 for more information. libsystemd and the associated header files need to be installed to use this option.
--with-bonjourBuild with support for Bonjour automatic service discovery. This requires Bonjour support in your operating system. Recommended on macOS.
--with-uuid=LIBRARY
         Build the uuid-ossp module
         (which provides functions to generate UUIDs), using the specified
         UUID library.
         LIBRARY must be one of:
        
           bsd to use the UUID functions found in FreeBSD
           and some other BSD-derived systems
          
           e2fs to use the UUID library created by
           the e2fsprogs project; this library is present in most
           Linux systems and in macOS, and can be obtained for other
           platforms as well
          
           ossp to use the OSSP UUID library
          
--with-ossp-uuid
         Obsolete equivalent of --with-uuid=ossp.
        
--with-libxmlBuild with libxml2, enabling SQL/XML support. Libxml2 version 2.6.23 or later is required for this feature.
         To detect the required compiler and linker options, PostgreSQL will
         query pkg-config, if that is installed and knows
         about libxml2.  Otherwise the program xml2-config,
         which is installed by libxml2, will be used if it is found.  Use
         of pkg-config is preferred, because it can deal
         with multi-architecture installations better.
        
         To use a libxml2 installation that is in an unusual location, you
         can set pkg-config-related environment
         variables (see its documentation), or set the environment variable
         XML2_CONFIG to point to
         the xml2-config program belonging to the libxml2
         installation, or set the variables XML2_CFLAGS
         and XML2_LIBS.  (If pkg-config is
         installed, then to override its idea of where libxml2 is you must
         either set XML2_CONFIG or set
         both XML2_CFLAGS and XML2_LIBS to
         nonempty strings.)
        
--with-libxslt
         Build with libxslt, enabling the
         xml2
         module to perform XSL transformations of XML.
         --with-libxml must be specified as well.
        
The options described in this section allow disabling certain PostgreSQL features that are built by default, but which might need to be turned off if the required software or system features are not available. Using these options is not recommended unless really necessary.
--without-readlinePrevents use of the Readline library (and libedit as well). This option disables command-line editing and history in psql.
--with-libedit-preferredFavors the use of the BSD-licensed libedit library rather than GPL-licensed Readline. This option is significant only if you have both libraries installed; the default in that case is to use Readline.
--without-zlibPrevents use of the Zlib library. This disables support for compressed archives in pg_dump and pg_restore.
--disable-spinlocksAllow the build to succeed even if PostgreSQL has no CPU spinlock support for the platform. The lack of spinlock support will result in very poor performance; therefore, this option should only be used if the build aborts and informs you that the platform lacks spinlock support. If this option is required to build PostgreSQL on your platform, please report the problem to the PostgreSQL developers.
--disable-atomicsDisable use of CPU atomic operations. This option does nothing on platforms that lack such operations. On platforms that do have them, this will result in poor performance. This option is only useful for debugging or making performance comparisons.
--disable-thread-safetyDisable the thread-safety of client libraries. This prevents concurrent threads in libpq and ECPG programs from safely controlling their private connection handles. Use this only on platforms with deficient threading support.
--with-includes=DIRECTORIES
         DIRECTORIES is a colon-separated list of
         directories that will be added to the list the compiler
         searches for header files. If you have optional packages
         (such as GNU Readline) installed in a non-standard
         location,
         you have to use this option and probably also the corresponding
         --with-libraries option.
        
         Example: --with-includes=/opt/gnu/include:/usr/sup/include.
        
--with-libraries=DIRECTORIES
         DIRECTORIES is a colon-separated list of
         directories to search for libraries. You will probably have
         to use this option (and the corresponding
         --with-includes option) if you have packages
         installed in non-standard locations.
        
         Example: --with-libraries=/opt/gnu/lib:/usr/sup/lib.
        
--with-system-tzdata=DIRECTORY
       
       
         PostgreSQL includes its own time zone database,
         which it requires for date and time operations.  This time zone
         database is in fact compatible with the IANA time zone
         database provided by many operating systems such as FreeBSD,
         Linux, and Solaris, so it would be redundant to install it again.
         When this option is used, the system-supplied time zone database
         in DIRECTORY is used instead of the one
         included in the PostgreSQL source distribution.
         DIRECTORY must be specified as an
         absolute path.  /usr/share/zoneinfo is a
         likely directory on some operating systems.  Note that the
         installation routine will not detect mismatching or erroneous time
         zone data.  If you use this option, you are advised to run the
         regression tests to verify that the time zone data you have
         pointed to works correctly with PostgreSQL.
        
This option is mainly aimed at binary package distributors who know their target operating system well. The main advantage of using this option is that the PostgreSQL package won't need to be upgraded whenever any of the many local daylight-saving time rules change. Another advantage is that PostgreSQL can be cross-compiled more straightforwardly if the time zone database files do not need to be built during the installation.
--with-extra-version=STRING
         Append STRING to the PostgreSQL version number.  You
         can use this, for example, to mark binaries built from unreleased Git
         snapshots or containing custom patches with an extra version string,
         such as a git describe identifier or a
         distribution package release number.
        
--disable-rpath
         Do not mark PostgreSQL's executables
         to indicate that they should search for shared libraries in the
         installation's library directory (see --libdir).
         On most platforms, this marking uses an absolute path to the
         library directory, so that it will be unhelpful if you relocate
         the installation later.  However, you will then need to provide
         some other way for the executables to find the shared libraries.
         Typically this requires configuring the operating system's
         dynamic linker to search the library directory; see
         Section 17.5.1 for more detail.
        
     It's fairly common, particularly for test builds, to adjust the
     default port number with --with-pgport.
     The other options in this section are recommended only for advanced
     users.
    
--with-pgport=NUMBER
         Set NUMBER as the default port number for
         server and clients. The default is 5432. The port can always
         be changed later on, but if you specify it here then both
         server and clients will have the same default compiled in,
         which can be very convenient.  Usually the only good reason
         to select a non-default value is if you intend to run multiple
         PostgreSQL servers on the same machine.
        
--with-krb-srvnam=NAME
         The default name of the Kerberos service principal used
         by GSSAPI.
         postgres is the default. There's usually no
         reason to change this unless you are building for a Windows
         environment, in which case it must be set to upper case
         POSTGRES.
        
--with-segsize=SEGSIZE
         Set the segment size, in gigabytes.  Large tables are
         divided into multiple operating-system files, each of size equal
         to the segment size.  This avoids problems with file size limits
         that exist on many platforms.  The default segment size, 1 gigabyte,
         is safe on all supported platforms.  If your operating system has
         “largefile” support (which most do, nowadays), you can use
         a larger segment size.  This can be helpful to reduce the number of
         file descriptors consumed when working with very large tables.
         But be careful not to select a value larger than is supported
         by your platform and the file systems you intend to use.  Other
         tools you might wish to use, such as tar, could
         also set limits on the usable file size.
         It is recommended, though not absolutely required, that this value
         be a power of 2.
         Note that changing this value breaks on-disk database compatibility,
         meaning you cannot use pg_upgrade to upgrade to
         a build with a different segment size.
        
--with-blocksize=BLOCKSIZE
         Set the block size, in kilobytes.  This is the unit
         of storage and I/O within tables.  The default, 8 kilobytes,
         is suitable for most situations; but other values may be useful
         in special cases.
         The value must be a power of 2 between 1 and 32 (kilobytes).
         Note that changing this value breaks on-disk database compatibility,
         meaning you cannot use pg_upgrade to upgrade to
         a build with a different block size.
        
--with-wal-blocksize=BLOCKSIZE
         Set the WAL block size, in kilobytes.  This is the unit
         of storage and I/O within the WAL log.  The default, 8 kilobytes,
         is suitable for most situations; but other values may be useful
         in special cases.
         The value must be a power of 2 between 1 and 64 (kilobytes).
         Note that changing this value breaks on-disk database compatibility,
         meaning you cannot use pg_upgrade to upgrade to
         a build with a different WAL block size.
        
     Most of the options in this section are only of interest for
     developing or debugging PostgreSQL.
     They are not recommended for production builds, except
     for --enable-debug, which can be useful to enable
     detailed bug reports in the unlucky event that you encounter a bug.
     On platforms supporting DTrace, --enable-dtrace
     may also be reasonable to use in production.
    
     When building an installation that will be used to develop code inside
     the server, it is recommended to use at least the
     options --enable-debug
     and --enable-cassert.
    
--enable-debugCompiles all programs and libraries with debugging symbols. This means that you can run the programs in a debugger to analyze problems. This enlarges the size of the installed executables considerably, and on non-GCC compilers it usually also disables compiler optimization, causing slowdowns. However, having the symbols available is extremely helpful for dealing with any problems that might arise. Currently, this option is recommended for production installations only if you use GCC. But you should always have it on if you are doing development work or running a beta version.
--enable-cassertEnables assertion checks in the server, which test for many “cannot happen” conditions. This is invaluable for code development purposes, but the tests can slow down the server significantly. Also, having the tests turned on won't necessarily enhance the stability of your server! The assertion checks are not categorized for severity, and so what might be a relatively harmless bug will still lead to server restarts if it triggers an assertion failure. This option is not recommended for production use, but you should have it on for development work or when running a beta version.
--enable-tap-tests
         Enable tests using the Perl TAP tools.  This requires a Perl
         installation and the Perl module IPC::Run.
         See Section 33.4 for more information.
        
--enable-dependEnables automatic dependency tracking. With this option, the makefiles are set up so that all affected object files will be rebuilt when any header file is changed. This is useful if you are doing development work, but is just wasted overhead if you intend only to compile once and install. At present, this option only works with GCC.
--enable-coverageIf using GCC, all programs and libraries are compiled with code coverage testing instrumentation. When run, they generate files in the build directory with code coverage metrics. See Section 33.5 for more information. This option is for use only with GCC and when doing development work.
--enable-profiling
         If using GCC, all programs and libraries are compiled so they
         can be profiled.  On backend exit, a subdirectory will be created
         that contains the gmon.out file containing
         profile data.
         This option is for use only with GCC and when doing development work.
        
--enable-dtraceCompiles PostgreSQL with support for the dynamic tracing tool DTrace. See Section 28.5 for more information.
         To point to the dtrace program, the
         environment variable DTRACE can be set.  This
         will often be necessary because dtrace is
         typically installed under /usr/sbin,
         which might not be in your PATH.
        
         Extra command-line options for the dtrace program
         can be specified in the environment variable
         DTRACEFLAGS.  On Solaris,
         to include DTrace support in a 64-bit binary, you must specify
         DTRACEFLAGS="-64".  For example,
         using the GCC compiler:
./configure CC='gcc -m64' --enable-dtrace DTRACEFLAGS='-64' ...
Using Sun's compiler:
./configure CC='/opt/SUNWspro/bin/cc -xtarget=native64' --enable-dtrace DTRACEFLAGS='-64' ...
configure Environment Variables
     In addition to the ordinary command-line options described above,
     configure responds to a number of environment
     variables.
     You can specify environment variables on the
     configure command line, for example:
./configure CC=/opt/bin/gcc CFLAGS='-O2 -pipe'
In this usage an environment variable is little different from a command-line option. You can also set such variables beforehand:
export CC=/opt/bin/gccexport CFLAGS='-O2 -pipe'./configure
This usage can be convenient because many programs' configuration scripts respond to these variables in similar ways.
     The most commonly used of these environment variables are
     CC and CFLAGS.
     If you prefer a C compiler different from the one
     configure picks, you can set the
     variable CC to the program of your choice.
     By default, configure will pick
     gcc if available, else the platform's
     default (usually cc).  Similarly, you can override the
     default compiler flags if needed with the CFLAGS variable.
    
Here is a list of the significant variables that can be set in this manner:
BISONBison program
CCC compiler
CFLAGSoptions to pass to the C compiler
CLANG
         path to clang program used to process source code
         for inlining when compiling with --with-llvm
        
CPPC preprocessor
CPPFLAGSoptions to pass to the C preprocessor
CXXC++ compiler
CXXFLAGSoptions to pass to the C++ compiler
DTRACE
         location of the dtrace program
        
DTRACEFLAGS
         options to pass to the dtrace program
        
FLEXFlex program
LDFLAGSoptions to use when linking either executables or shared libraries
LDFLAGS_EXadditional options for linking executables only
LDFLAGS_SLadditional options for linking shared libraries only
LLVM_CONFIG
         llvm-config program used to locate the
         LLVM installation
        
MSGFMT
         msgfmt program for native language support
        
PERL
         Perl interpreter program.  This will be used to determine the
         dependencies for building PL/Perl.  The default is
         perl.
        
PYTHON
         Python interpreter program.  This will be used to
         determine the dependencies for building PL/Python.  Also,
         whether Python 2 or 3 is specified here (or otherwise
         implicitly chosen) determines which variant of the PL/Python
         language becomes available.  See
         Section 46.1
         for more information.  If this is not set, the following are probed
         in this order: python python3 python2.
        
TCLSH
         Tcl interpreter program.  This will be used to
         determine the dependencies for building PL/Tcl.
         If this is not set, the following are probed in this
         order: tclsh tcl tclsh8.6 tclsh86 tclsh8.5 tclsh85
         tclsh8.4 tclsh84.
        
XML2_CONFIG
         xml2-config program used to locate the
         libxml2 installation
        
     Sometimes it is useful to add compiler flags after-the-fact to the set
     that were chosen by configure.  An important example is
     that gcc's -Werror option cannot be included
     in the CFLAGS passed to configure, because
     it will break many of configure's built-in tests.  To add
     such flags, include them in the COPT environment variable
     while running make.  The contents of COPT
     are added to both the CFLAGS and LDFLAGS
     options set up by configure.  For example, you could do
make COPT='-Werror'
or
export COPT='-Werror'make
      If using GCC, it is best to build with an optimization level of
      at least -O1, because using no optimization
      (-O0) disables some important compiler warnings (such
      as the use of uninitialized variables).  However, non-zero
      optimization levels can complicate debugging because stepping
      through compiled code will usually not match up one-to-one with
      source code lines.  If you get confused while trying to debug
      optimized code, recompile the specific files of interest with
      -O0.  An easy way to do this is by passing an option
      to make: make PROFILE=-O0 file.o.
     
      The COPT and PROFILE environment variables are
      actually handled identically by the PostgreSQL
      makefiles.  Which to use is a matter of preference, but a common habit
      among developers is to use PROFILE for one-time flag
      adjustments, while COPT might be kept set all the time.