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A copy of Fedora's postgresql readme
PostgreSQL in RPMs
--------------------------------------------------------------------------
INTRODUCTION
This document exists to explain the layout of the RPMs for PostgreSQL, to
describe various RPM specifics, and to document special features found in
the RPMset.
This document is written to be applicable to version 10 of PostgreSQL,
which is the current version of the RPMs as of this writing. More to the
point, versions prior to 10 are not documented here.
This document is intended for use only with the RPMs supplied in Red Hat
Enterprise Linux, CentOS and Fedora. Note that there are also "PGDG" RPMs
available directly from the upstream PostgreSQL project. Those are
slightly different.
--------------------------------------------------------------------------
QUICKSTART
For a fresh installation, you will need to initialize the cluster first
(as a root user):
# postgresql-setup --initdb
and it will prepare a new database cluster for you. Then you will need to
start PostgreSQL. Now, as root, run:
# systemctl start postgresql.service
This command will start a postmaster that will listen on localhost and
Unix socket 5432 only. Edit /var/lib/pgsql/data/postgresql.conf and
pg_hba.conf if you want to allow remote access -- see the section on Grand
Unified Configuration. You will probably also want to do
# systemctl enable postgresql.service
so that the postmaster is automatically started during future reboots.
The file /var/lib/pgsql/.bash_profile is packaged to help with the setting
of environment variables. You may edit this file, and it won't be
overwritten during a package upgrade. However, enhancements and bugfixes
may be added to this file, so be sure to check .bash_profile.rpmnew after
upgrading.
The user 'postgres' is created during installation of the server
subpackage. This user by default is UID and GID 26. The user has the
default shell set to bash, and the home directory set to /var/lib/pgsql.
This user also has no default password, so the only way to become this
user is to su to it from root. If you want to be able to su to it from a
non-root account or log in directly as 'postgres' you will need to set a
password using passwd.
--------------------------------------------------------------------------
UPGRADING AN INSTALLATION
For a minor-version upgrade (such as 9.3.1 to 9.3.4 for versions < 10, or
10.1 to 10.5 for versions >= 10; last number changes), just install the
new RPMs; there's usually nothing more to it than that. Upgrading across a
major release of PostgreSQL (for example, from 9.2.x to 9.3.x or from 10
to 11) requires more effort.
If you are upgrading across more than one major release of PostgreSQL (for
example, from 8.3.x to 9.0.x), you will need to follow the "traditional"
dump and reload process to bring your data into the new version. That is:
*before* upgrading, run pg_dumpall to extract all your data into a SQL
file. Shut down the old postmaster, upgrade to the new version RPMs,
perform initdb, and run the dump file through psql to restore your data.
In some major releases, the RPMs also support faster upgrade from concrete
subset of previous releases. You can run the:
$ postgresql-setup --upgrade-ids
to see what previous versions you are able to upgrade from. This is much
faster than a dump and reload. To do a faster upgrade:
1. shut down the old postmaster running against old data
2. optionally make a backup of data directory (recommended!)
3. install the new version's RPMs (install all the ones you had before,
plus postgresql-upgrade)
4. as root, run "postgresql-setup --upgrade [--upgrade-from ID]"
5. update the configuration files /var/lib/pgsql/data/*.conf with any
customizations you had before (your old configuration files are in old
data directory or in /var/lib/pgsql/data-old/ if you've done in-place
upgrade)
6. as root, run "systemctl start postgresql.service"
7. the old data directory can be removed after the update is complete, as
can postgresql-upgrade package
NOTE: The in-place upgrade process is new and relatively poorly tested, so
if your data is critical it's a really good idea to make a tarball backup
of old data directory before running the upgrade. This will let you get
back to where you were in case of disaster.
--------------------------------------------------------------------------
POSTGRESQL RPM PACKAGES AND RATIONALE
PostgreSQL is split up into multiple packages so that users can 'pick and
choose' what pieces are needed, and what dependencies are required.
Table 1. Sub-package list
+------------------------------------------------------------------------+
| Package | Description |
|-----------------------+------------------------------------------------|
| postgresql: | Key client programs and basic documentation |
|-----------------------+------------------------------------------------|
| postgresql-libs: | Client shared libraries |
|-----------------------+------------------------------------------------|
| postgresql-server: | Server executables and data files |
|-----------------------+------------------------------------------------|
| postgresql-test: | The regression tests and associated files |
|-----------------------+------------------------------------------------|
| postgresql-docs: | Full documentation in HTML and PDF, the |
| | tutorial files |
|-----------------------+------------------------------------------------|
| postgresql-contrib: | Add-on loadable modules and programs |
|-----------------------+------------------------------------------------|
| postgresql-plperl: | PL/Perl procedural language |
|-----------------------+------------------------------------------------|
| postgresql-plpython: | PL/Python procedural language (for Python 2) |
|-----------------------+------------------------------------------------|
| postgresql-plpython3: | PL/Python procedural language (for Python 3) |
|-----------------------+------------------------------------------------|
| postgresql-pltcl: | PL/Tcl procedural language |
+------------------------------------------------------------------------+
You have to install postgresql and postgresql-libs to do anything. Package
postgresql-server is needed unless you only plan to use the clients to
work with a remote PostgreSQL server. The others are optional.
Note that there are no postgresql-perl, postgresql-jdbc, postgresql-odbc,
postgresql-python, postgresql-tcl, or postgresql-tk subpackages any
longer. Those programs have been split off into separate source
distributions. They are still available, but in some cases not under those
RPM names.
--------------------------------------------------------------------------
RPM FILE LOCATIONS
To be in compliance with the Linux FHS, the PostgreSQL RPMs install files
in a manner not consistent with most of the PostgreSQL documentation.
According to the standard PostgreSQL documentation, PostgreSQL is
installed under the directory /usr/local/pgsql, with executables, source,
and data existing in various subdirectories.
Different distributions have different ideas of some of these file
locations. In particular, the documentation directory can be /usr/doc,
/usr/doc/packages, /usr/share/doc, /usr/share/doc/packages, or some other
similar path.
However, this installation (which usually matches the Red Hat / CentOS /
Fedora RPM's) install the files like:
Table 2. Filesystem layout
+------------------------------------------------------------------------+
| Description | Directory |
|-----------------------+------------------------------------------------|
| Executables | /usr/bin |
|-----------------------+------------------------------------------------|
| Libraries | /usr/lib64 |
|-----------------------+------------------------------------------------|
| Documentation | /usr/share/doc/postgresql/html |
|-----------------------+------------------------------------------------|
| PDF documentation | /usr/share/doc/postgresql |
|-----------------------+------------------------------------------------|
| Contrib documentation | /usr/share/doc/postgresql-contrib |
|-----------------------+------------------------------------------------|
| Source | not installed |
|-----------------------+------------------------------------------------|
| Data | /var/lib/pgsql/data |
|-----------------------+------------------------------------------------|
| Backup area | /var/lib/pgsql/backups |
|-----------------------+------------------------------------------------|
| Templates | /usr/share/pgsql |
|-----------------------+------------------------------------------------|
| Procedural Languages | /usr/lib64/pgsql |
|-----------------------+------------------------------------------------|
| Development Headers | /usr/include/pgsql |
|-----------------------+------------------------------------------------|
| Other shared data | /usr/share/pgsql |
|-----------------------+------------------------------------------------|
| Regression tests | /usr/lib64/pgsql/test/regress (in the -test |
| | package) |
+------------------------------------------------------------------------+
While it may seem gratuitous to place these files in different locations,
the FHS requires it -- distributions should not ever touch /usr/local. It
may also seem like more work to keep track of where everything is -- but,
that's the beauty of RPM -- you don't have to keep track of the files, RPM
does it for you.
These RPMs are designed to be LSB-compliant -- if you find this not to be
the case, please let us know by way of the pgsql-pkg-yum@postgresql.org
mailing list.
--------------------------------------------------------------------------
MULTIPLE POSTMASTERS
The postgresql-server package contains a systemd "unit" files
postgresql.service and postgresql@.service. The first file is used solely
to start the default PostgreSQL server. The second one is designed to
allow instantiating additional PostgreSQL servers on same machine.
As an example, let us create a secondary PostgreSQL service called,
creatively enough, 'postgresql@secondary'. Here are the steps:
1. Run the following command to create the necessary systemd
configuration:
# postgresql-new-systemd-unit \
--unit postgresql@secondary \
--datadir /path/to/data/directory
And then run this command to initialize the new database cluster:
$ postgresql-setup --initdb \
--unit postgresql@secondary \
--port NNNN
Replace the "/path/to/data/directory" path and NNNN port with
appropriate settings that don't conflict with any other PostgreSQL
setup. Make sure that the parent directory of specified path has
appropriate ownership and permissions. Note the SELinux issues
mentioned below.
2. Edit postgresql.conf in the target 'datadir' directory to change
settings as needed.
3. Start the new service with this command:
# systemctl start postgresql@secondary.service
You will probably also want to run the command
# systemctl enable postgresql@secondary.service
so that the new service is automatically started in future reboots.
When doing a major-version upgrade of a secondary service, add the service
name to the postgresql-setup command, for example:
# postgresql-setup --upgrade --unit postgresql@secondary
This will let postgresql-setup find the correct data directory from the
proper configuration file.
If you are running SELinux in enforcing mode (which is highly recommended,
particularly for network-exposed services like PostgreSQL) you will need
to adjust SELinux policy to allow the secondary server to use non-default
PGPORT or PGDATA settings. To allow use of a non-default port, say 5433,
do this as root:
# semanage port -a -t postgresql_port_t -p tcp 5433
To allow use of a non-default data directory, say /special/pgdata, do:
# semanage fcontext -a -t postgresql_db_t "/special/pgdata(/.*)?"
If you already created the directory, follow that with:
# restorecon -R /special/pgdata
These settings are persistent across reboots. For more information see
"man semanage".
--------------------------------------------------------------------------
REGRESSION TESTING
If you install the postgresql-test RPM then you can run the PostgreSQL
regression tests. These tests stress your database installation and
produce results that give you assurances that the installation is
complete, and that your database machine is up to the task.
To run the regression tests under the RPM installation, make sure that the
PostgreSQL server has been started (if not, su to root and do
# systemctl start postgresql.service
su to postgres, cd to /usr/lib64/pgsql/test/regress and execute "make
check". This command will start the regression tests and will both show
the results to the screen and store the results in the file regress.out.
If any tests fail, see the file regression.diffs in that directory for
details, and read the "Regression Tests" section of the PostgreSQL
documentation to find out whether the differences are actually
significant. If you need help interpreting the results, contact the
pgsql-general list at postgresql.org.
After testing, run "make clean" to remove the files generated by the test
script. Then you can remove the postgresql-test RPM, if you wish.
--------------------------------------------------------------------------
STARTING POSTMASTER AUTOMATICALLY AT SYSTEM STARTUP
Fedora / Red Hat / CentOS use the systemd package to manage server
startup. A systemd unit file for PostgreSQL is provided in the server
package, as /usr/lib/systemd/system/postgresql.service. To start the
postmaster manually, as root run
# systemctl start postgresql.service
To shut the postmaster down,
# systemctl stop postgresql.service
These two commands only change the postmaster's current status. If you
want the postmaster to be started automatically during future system
startups, run
# systemctl enable postgresql.service
To undo that again,
# systemctl disable postgresql.service
See "man systemctl" for other possible subcommands.)
--------------------------------------------------------------------------
GRAND UNIFIED CONFIGURATION (GUC) FILE
The PostgreSQL server has many tunable parameters -- the file
/var/lib/pgsql/data/postgresql.conf is the master configuration file for
the whole system.
The RPM ships with a mostly-default file -- you will need to tune the
parameters for your installation. In particular, you might want to allow
nonlocal TCP/IP socket connections -- in order to allow these, you will
need to edit the postgresql.conf file. The line in question contains the
string 'listen_addresses' -- you need to both uncomment the line and set
the value to '*' to get the postmaster to accept nonlocal connections.
You'll also need to adjust pg_hba.conf appropriately.
--------------------------------------------------------------------------
LOGGING SET UP
By default, the postmaster's stderr log is directed into files placed in a
pg_log subdirectory of the data directory (ie,
/var/lib/pgsql/data/pg_log). The out-of-the-box configuration rotates
among seven files, one for each day of the week. You can adjust this by
changing postgresql.conf settings.
--------------------------------------------------------------------------
REBUILDING FROM SOURCE RPM
If your distribution is not supported by the binary RPMs from
PostgreSQL.org, you will need to rebuild from the source RPM.
If you have not previously rebuilt any RPMs, set up the required
environment: make a work directory, say ~/rpmwork, then cd into it and do
# mkdir BUILD BUILDROOT RPMS SOURCES SPECS SRPMS
Then make a file ~/.rpmmacros containing
%_topdir full_path_to_work_directory_here
Download the postgresql .src.rpm for the release you want and place it in
the SRPMS subdirectory, then cd there and execute
$ rpmbuild --rebuild postgresql-nnn.src.rpm
The results will appear under the RPMS subdirectory.
You will have to have a full development environment to rebuild the RPM
set. If rpmbuild complains of lack of certain packages, install them and
try again. In some cases, you can disable features to avoid needing some
development packages, as detailed next.
This release of the RPMset includes the ability to conditionally build
sets of packages. The parameters, their defaults, and the meanings are:
Table 3. SRPM configuration options
+------------------------------------------------------------------------+
| Variable Default Comment |
| beta 0 build with cassert and do not strip the binaries |
| runselftest 1 do "make check" during the build |
| test 1 build the postgresql-test package |
| upgrade 1 build the postgresql-upgrade package |
| plpython 1 build the PL/Python procedural language package |
| plpython3 1 build the PL/Python3 procedural language package |
| pltcl 1 build the PL/Tcl procedural language package |
| plperl 1 build the PL/Perl procedural language package |
| ssl 1 build with OpenSSL support |
| kerberos 1 build with Kerberos 5 support |
| ldap 1 build with LDAP support |
| nls 1 build with national language support |
| pam 1 build with PAM support |
| sdt 1 build with SystemTap support |
| xml 1 build with XML support |
| pgfts 1 build with --enable-thread-safety |
| selinux 1 build contrib/selinux |
| uuid 1 build contrib/uuid-ossp |
+------------------------------------------------------------------------+
To use these defines, invoke a rebuild like this:
$ rpmbuild --rebuild \
--define 'plpython 0' \
--define 'pltcl 0' \
--define 'test 0' \
--define 'runselftest 0' \
--define 'kerberos 0' \
postgresql-9.2.0-1.src.rpm
This command would disable the plpython, pltcl, and test subpackages,
disable the regression test run during build, and disable kerberos
support.
You might need to disable runselftest if there is an installed version of
PostgreSQL that is a different major version from what you are trying to
build. The self test tends to pick up the installed libpq.so shared
library in place of the one being built :-(, so if that isn't compatible
the test will fail. Also, you can't use runselftest when doing the build
as root.
More of these conditionals will be added in the future.
--------------------------------------------------------------------------
CONTRIB FILES
The contents of the contrib tree are packaged into the -contrib subpackage
and are processed with make and make install. There is documentation in
/usr/share/doc/postgresql-contrib for these modules. Most of the modules
are in /usr/lib64/pgsql for loadable modules, and binaries are in
/usr/bin. In the future these files may be split out, depending upon
function and dependencies.
--------------------------------------------------------------------------
MORE INFORMATION
You can get more information at http://www.postgresql.org and
http://yum.postgresql.org
Please help make this packaging better -- let us know if you find
problems, or better ways of doing things. You can reach us by e-mail at
pgsql-pkg-yum@postgresql.org or fail a bug against postgresql component on
bugzilla.redhat.com.
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