Provided by: postgresql-10_10.5-1_amd64 bug

NAME

       pg_upgrade - upgrade a PostgreSQL server instance

SYNOPSIS

       pg_upgrade -b oldbindir -B newbindir -d oldconfigdir -D newconfigdir [option...]

DESCRIPTION

       pg_upgrade (formerly called pg_migrator) allows data stored in PostgreSQL data files to be
       upgraded to a later PostgreSQL major version without the data dump/reload typically
       required for major version upgrades, e.g. from 9.5.8 to 9.6.4 or from 10.7 to 11.2. It is
       not required for minor version upgrades, e.g. from 9.6.2 to 9.6.3 or from 10.1 to 10.2.

       Major PostgreSQL releases regularly add new features that often change the layout of the
       system tables, but the internal data storage format rarely changes.  pg_upgrade uses this
       fact to perform rapid upgrades by creating new system tables and simply reusing the old
       user data files. If a future major release ever changes the data storage format in a way
       that makes the old data format unreadable, pg_upgrade will not be usable for such
       upgrades. (The community will attempt to avoid such situations.)

       pg_upgrade does its best to make sure the old and new clusters are binary-compatible, e.g.
       by checking for compatible compile-time settings, including 32/64-bit binaries. It is
       important that any external modules are also binary compatible, though this cannot be
       checked by pg_upgrade.

       pg_upgrade supports upgrades from 8.4.X and later to the current major release of
       PostgreSQL, including snapshot and beta releases.

OPTIONS

       pg_upgrade accepts the following command-line arguments:

       -b bindir
       --old-bindir=bindir
           the old PostgreSQL executable directory; environment variable PGBINOLD

       -B bindir
       --new-bindir=bindir
           the new PostgreSQL executable directory; environment variable PGBINNEW

       -c
       --check
           check clusters only, don't change any data

       -d configdir
       --old-datadir=configdir
           the old database cluster configuration directory; environment variable PGDATAOLD

       -D configdir
       --new-datadir=configdiry
           the new database cluster configuration directory; environment variable PGDATANEW

       -j
       --jobs
           number of simultaneous processes or threads to use

       -k
       --link
           use hard links instead of copying files to the new cluster

       -o options
       --old-options options
           options to be passed directly to the old postgres command; multiple option invocations
           are appended

       -O options
       --new-options options
           options to be passed directly to the new postgres command; multiple option invocations
           are appended

       -p port
       --old-port=port
           the old cluster port number; environment variable PGPORTOLD

       -P port
       --new-port=port
           the new cluster port number; environment variable PGPORTNEW

       -r
       --retain
           retain SQL and log files even after successful completion

       -U username
       --username=username
           cluster's install user name; environment variable PGUSER

       -v
       --verbose
           enable verbose internal logging

       -V
       --version
           display version information, then exit

       -?
       --help
           show help, then exit

USAGE

       These are the steps to perform an upgrade with pg_upgrade:

        1. Optionally move the old cluster: If you are using a version-specific installation
           directory, e.g.  /opt/PostgreSQL/10, you do not need to move the old cluster. The
           graphical installers all use version-specific installation directories.

           If your installation directory is not version-specific, e.g.  /usr/local/pgsql, it is
           necessary to move the current PostgreSQL install directory so it does not interfere
           with the new PostgreSQL installation. Once the current PostgreSQL server is shut down,
           it is safe to rename the PostgreSQL installation directory; assuming the old directory
           is /usr/local/pgsql, you can do:

               mv /usr/local/pgsql /usr/local/pgsql.old

           to rename the directory.

        2. For source installs, build the new version: Build the new PostgreSQL source with
           configure flags that are compatible with the old cluster.  pg_upgrade will check
           pg_controldata to make sure all settings are compatible before starting the upgrade.

        3. Install the new PostgreSQL binaries: Install the new server's binaries and support
           files.  pg_upgrade is included in a default installation.

           For source installs, if you wish to install the new server in a custom location, use
           the prefix variable:

               make prefix=/usr/local/pgsql.new install

        4. Initialize the new PostgreSQL cluster: Initialize the new cluster using initdb. Again,
           use compatible initdb flags that match the old cluster. Many prebuilt installers do
           this step automatically. There is no need to start the new cluster.

        5. Install custom shared object files: Install any custom shared object files (or DLLs)
           used by the old cluster into the new cluster, e.g.  pgcrypto.so, whether they are from
           contrib or some other source. Do not install the schema definitions, e.g.  CREATE
           EXTENSION pgcrypto, because these will be upgraded from the old cluster. Also, any
           custom full text search files (dictionary, synonym, thesaurus, stop words) must also
           be copied to the new cluster.

        6. Adjust authentication: pg_upgrade will connect to the old and new servers several
           times, so you might want to set authentication to peer in pg_hba.conf or use a
           ~/.pgpass file (see Section 33.15).

        7. Stop both servers: Make sure both database servers are stopped using, on Unix, e.g.:

               pg_ctl -D /opt/PostgreSQL/9.6 stop
               pg_ctl -D /opt/PostgreSQL/10 stop

           or on Windows, using the proper service names:

               NET STOP postgresql-9.6
               NET STOP postgresql-10

           Streaming replication and log-shipping standby servers can remain running until a
           later step.

        8. Prepare for standby server upgrades: If you are upgrading standby servers using
           methods outlined in section Step 10, verify that the old standby servers are caught up
           by running pg_controldata against the old primary and standby clusters. Verify that
           the “Latest checkpoint location” values match in all clusters. (There will be a
           mismatch if old standby servers were shut down before the old primary.) Also, change
           wal_level to replica in the postgresql.conf file on the new primary cluster.

        9. Run pg_upgrade: Always run the pg_upgrade binary of the new server, not the old one.
           pg_upgrade requires the specification of the old and new cluster's data and executable
           (bin) directories. You can also specify user and port values, and whether you want the
           data files linked instead of the default copy behavior.

           If you use link mode, the upgrade will be much faster (no file copying) and use less
           disk space, but you will not be able to access your old cluster once you start the new
           cluster after the upgrade. Link mode also requires that the old and new cluster data
           directories be in the same file system. (Tablespaces and pg_wal can be on different
           file systems.) See pg_upgrade --help for a full list of options.

           The --jobs option allows multiple CPU cores to be used for copying/linking of files
           and to dump and reload database schemas in parallel; a good place to start is the
           maximum of the number of CPU cores and tablespaces. This option can dramatically
           reduce the time to upgrade a multi-database server running on a multiprocessor
           machine.

           For Windows users, you must be logged into an administrative account, and then start a
           shell as the postgres user and set the proper path:

               RUNAS /USER:postgres "CMD.EXE"
               SET PATH=%PATH%;C:\Program Files\PostgreSQL\10\bin;

           and then run pg_upgrade with quoted directories, e.g.:

               pg_upgrade.exe
                       --old-datadir "C:/Program Files/PostgreSQL/9.6/data"
                       --new-datadir "C:/Program Files/PostgreSQL/10/data"
                       --old-bindir "C:/Program Files/PostgreSQL/9.6/bin"
                       --new-bindir "C:/Program Files/PostgreSQL/10/bin"

           Once started, pg_upgrade will verify the two clusters are compatible and then do the
           upgrade. You can use pg_upgrade --check to perform only the checks, even if the old
           server is still running.  pg_upgrade --check will also outline any manual adjustments
           you will need to make after the upgrade. If you are going to be using link mode, you
           should use the --link option with --check to enable link-mode-specific checks.
           pg_upgrade requires write permission in the current directory.

           Obviously, no one should be accessing the clusters during the upgrade.  pg_upgrade
           defaults to running servers on port 50432 to avoid unintended client connections. You
           can use the same port number for both clusters when doing an upgrade because the old
           and new clusters will not be running at the same time. However, when checking an old
           running server, the old and new port numbers must be different.

           If an error occurs while restoring the database schema, pg_upgrade will exit and you
           will have to revert to the old cluster as outlined in Step 16 below. To try pg_upgrade
           again, you will need to modify the old cluster so the pg_upgrade schema restore
           succeeds. If the problem is a contrib module, you might need to uninstall the contrib
           module from the old cluster and install it in the new cluster after the upgrade,
           assuming the module is not being used to store user data.

        10. Upgrade Streaming Replication and Log-Shipping standby servers: If you used link mode
           and have Streaming Replication (see Section 26.2.5) or Log-Shipping (see Section 26.2)
           standby servers, you can follow these steps to quickly upgrade them. You will not be
           running pg_upgrade on the standby servers, but rather rsync on the primary. Do not
           start any servers yet.

           If you did not use link mode, do not have or do not want to use rsync, or want an
           easier solution, skip the instructions in this section and simply recreate the standby
           servers once pg_upgrade completes and the new primary is running.  Install the new
           PostgreSQL binaries on standby servers: Make sure the new binaries and support files
           are installed on all standby servers.  Make sure the new standby data directories do
           not exist: Make sure the new standby data directories do not exist or are empty. If
           initdb was run, delete the standby servers' new data directories.  Install custom
           shared object files: Install the same custom shared object files on the new standbys
           that you installed in the new primary cluster.  Stop standby servers: If the standby
           servers are still running, stop them now using the above instructions.  Save
           configuration files: Save any configuration files from the old standbys' configuration
           directories you need to keep, e.g.  postgresql.conf, recovery.conf, because these will
           be overwritten or removed in the next step.  Run rsync: When using link mode, standby
           servers can be quickly upgraded using rsync. To accomplish this, from a directory on
           the primary server that is above the old and new database cluster directories, run
           this on the primary for each standby server:

               rsync --archive --delete --hard-links --size-only --no-inc-recursive old_cluster new_cluster remote_dir

           where old_cluster and new_cluster are relative to the current directory on the
           primary, and remote_dir is above the old and new cluster directories on the standby.
           The directory structure under the specified directories on the primary and standbys
           must match. Consult the rsync manual page for details on specifying the remote
           directory, e.g.

               rsync --archive --delete --hard-links --size-only --no-inc-recursive /opt/PostgreSQL/9.5 \
                     /opt/PostgreSQL/9.6 standby.example.com:/opt/PostgreSQL

           You can verify what the command will do using rsync's --dry-run option. While rsync
           must be run on the primary for at least one standby, it is possible to run rsync on an
           upgraded standby to upgrade other standbys, as long as the upgraded standby has not
           been started.

           What this does is to record the links created by pg_upgrade's link mode that connect
           files in the old and new clusters on the primary server. It then finds matching files
           in the standby's old cluster and creates links for them in the standby's new cluster.
           Files that were not linked on the primary are copied from the primary to the standby.
           (They are usually small.) This provides rapid standby upgrades. Unfortunately, rsync
           needlessly copies files associated with temporary and unlogged tables because these
           files don't normally exist on standby servers.

           If you have tablespaces, you will need to run a similar rsync command for each
           tablespace directory, e.g.:

               rsync --archive --delete --hard-links --size-only --no-inc-recursive /vol1/pg_tblsp/PG_9.5_201510051 \
                     /vol1/pg_tblsp/PG_9.6_201608131 standby.example.com:/vol1/pg_tblsp

           If you have relocated pg_wal outside the data directories, rsync must be run on those
           directories too.  Configure streaming replication and log-shipping standby servers:
           Configure the servers for log shipping. (You do not need to run pg_start_backup() and
           pg_stop_backup() or take a file system backup as the standbys are still synchronized
           with the primary.)

        11. Restore pg_hba.conf: If you modified pg_hba.conf, restore its original settings. It
           might also be necessary to adjust other configuration files in the new cluster to
           match the old cluster, e.g.  postgresql.conf.

        12. Start the new server: The new server can now be safely started, and then any rsync'ed
           standby servers.

        13. Post-Upgrade processing: If any post-upgrade processing is required, pg_upgrade will
           issue warnings as it completes. It will also generate script files that must be run by
           the administrator. The script files will connect to each database that needs
           post-upgrade processing. Each script should be run using:

               psql --username=postgres --file=script.sql postgres

           The scripts can be run in any order and can be deleted once they have been run.

               Caution
               In general it is unsafe to access tables referenced in rebuild scripts until the
               rebuild scripts have run to completion; doing so could yield incorrect results or
               poor performance. Tables not referenced in rebuild scripts can be accessed
               immediately.

        14. Statistics: Because optimizer statistics are not transferred by pg_upgrade, you will
           be instructed to run a command to regenerate that information at the end of the
           upgrade. You might need to set connection parameters to match your new cluster.

        15. Delete old cluster: Once you are satisfied with the upgrade, you can delete the old
           cluster's data directories by running the script mentioned when pg_upgrade completes.
           (Automatic deletion is not possible if you have user-defined tablespaces inside the
           old data directory.) You can also delete the old installation directories (e.g.  bin,
           share).

        16. Reverting to old cluster: If, after running pg_upgrade, you wish to revert to the old
           cluster, there are several options:

           ·   If you ran pg_upgrade with --check, no modifications were made to the old cluster
               and you can re-use it anytime.

           ·   If you ran pg_upgrade with --link, the data files are shared between the old and
               new cluster. If you started the new cluster, the new server has written to those
               shared files and it is unsafe to use the old cluster.

           ·   If you ran pg_upgrade without --link or did not start the new server, the old
               cluster was not modified except that, if linking started, a .old suffix was
               appended to $PGDATA/global/pg_control. To reuse the old cluster, possibly remove
               the .old suffix from $PGDATA/global/pg_control; you can then restart the old
               cluster.

NOTES

       pg_upgrade does not support upgrading of databases containing these reg* OID-referencing
       system data types: regproc, regprocedure, regoper, regoperator, regconfig, and
       regdictionary. (regtype can be upgraded.)

       All failure, rebuild, and reindex cases will be reported by pg_upgrade if they affect your
       installation; post-upgrade scripts to rebuild tables and indexes will be generated
       automatically. If you are trying to automate the upgrade of many clusters, you should find
       that clusters with identical database schemas require the same post-upgrade steps for all
       cluster upgrades; this is because the post-upgrade steps are based on the database
       schemas, and not user data.

       For deployment testing, create a schema-only copy of the old cluster, insert dummy data,
       and upgrade that.

       If you are upgrading a pre-PostgreSQL 9.2 cluster that uses a configuration-file-only
       directory, you must pass the real data directory location to pg_upgrade, and pass the
       configuration directory location to the server, e.g.  -d /real-data-directory -o '-D
       /configuration-directory'.

       If using a pre-9.1 old server that is using a non-default Unix-domain socket directory or
       a default that differs from the default of the new cluster, set PGHOST to point to the old
       server's socket location. (This is not relevant on Windows.)

       If you want to use link mode and you do not want your old cluster to be modified when the
       new cluster is started, make a copy of the old cluster and upgrade that in link mode. To
       make a valid copy of the old cluster, use rsync to create a dirty copy of the old cluster
       while the server is running, then shut down the old server and run rsync --checksum again
       to update the copy with any changes to make it consistent. (--checksum is necessary
       because rsync only has file modification-time granularity of one second.) You might want
       to exclude some files, e.g.  postmaster.pid, as documented in Section 25.3.3. If your file
       system supports file system snapshots or copy-on-write file copies, you can use that to
       make a backup of the old cluster and tablespaces, though the snapshot and copies must be
       created simultaneously or while the database server is down.

SEE ALSO

       initdb(1), pg_ctl(1), pg_dump(1), postgres(1)