database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-30 11:03:19 +03:00
Code Activity

Add pg_upgrade to /contrib; will be in 9.0 beta2.

Browse Source 
Add documentation.

Supports migration from PG 8.3 and 8.4.
This commit is contained in:
Bruce Momjian
2010-05-12 02:19:11 +00:00
parent 28e1742217
commit c2e9b2f288
22 changed files with 6384 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
doc/src/sgml/contrib.sgml
View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/contrib.sgml,v 1.16 2010/01/28 23:59:52 adunstan Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/contrib.sgml,v 1.17 2010/05/12 02:19:11 momjian Exp $ -->
<appendix id="contrib">
<title>Additional Supplied Modules</title>
@ -110,6 +110,7 @@ psql -d dbname -f <replaceable>SHAREDIR</>/contrib/<replaceable>module</>.sql
&pgstatstatements;
&pgstattuple;
&pgtrgm;
&pgupgrade;
&seg;
&contrib-spi;
&sslinfo;

3
doc/src/sgml/filelist.sgml
View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/filelist.sgml,v 1.67 2010/02/22 11:47:30 heikki Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/filelist.sgml,v 1.68 2010/05/12 02:19:11 momjian Exp $ -->
<!entity history SYSTEM "history.sgml">
<!entity info SYSTEM "info.sgml">
@ -122,6 +122,7 @@
<!entity pgstatstatements SYSTEM "pgstatstatements.sgml">
<!entity pgstattuple SYSTEM "pgstattuple.sgml">
<!entity pgtrgm SYSTEM "pgtrgm.sgml">
<!entity pgupgrade SYSTEM "pgupgrade.sgml">
<!entity seg SYSTEM "seg.sgml">
<!entity contrib-spi SYSTEM "contrib-spi.sgml">
<!entity sslinfo SYSTEM "sslinfo.sgml">

441
doc/src/sgml/pgupgrade.sgml Normal file
View File

@ -0,0 +1,441 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/pgupgrade.sgml,v 1.1 2010/05/12 02:19:11 momjian Exp $ -->
<sect1 id="pgupgrade">
<title>pg_upgrade</title>
<indexterm zone="pgupgrade">
<primary>pg_upgrade</primary>
</indexterm>
<para>
<application>pg_upgrade</> (formerly called pg_migrator) allows data
stored in Postgres data files to be migrated to a later Postgres
major version without the data dump/reload typically required for
major version upgrades, e.g. from 8.4.7 to the current major release
of Postgres. It is not required for minor version upgrades, e.g.
9.0.1 -> 9.0.4.
</para>
<sect2>
<title>Supported Versions</title>
<para>
pg_upgrade supports upgrades from 8.3.X and later to the current
major release of Postgres, including snapshot and alpha releases.
pg_upgrade also supports upgrades from EnterpriseDB's Postgres Plus
Advanced Server.
</para>
</sect2>
<sect2>
<title>Upgrade Steps</title>
<orderedlist>
<listitem>
<para>
Optionally move the old cluster
</para>
<para>
If you are using a version-specific PostgreSQL install directory, e.g.
/opt/PostgreSQL/8.4, you do not need to move the old cluster. The
one-click installers all use version-specific install directories.
</para>
<para>
If your PostgreSQL install directory is not version-specific, e.g.
/usr/local/pgsql, it is necessary to move the current Postgres install
directory so it does not interfere with the new Postgres installation.
Once the current Postgres server is shut down, it is safe to rename the
Postgres install directory; assuming the old directory is
/usr/local/pgsql, you can do:
<programlisting>
mv /usr/local/pgsql /usr/local/pgsql.old
</programlisting>
to rename the directory.
</para>
<para>
If you are using tablespaces and migrating to 8.4 or earlier, there must
be sufficient directory permissions to allow pg_upgrade to rename each
tablespace directory to add a ".old" suffix.
</para>
</listitem>
<listitem>
<para>
For PostgreSQL source installs, build the new PostgreSQL version
</para>
<para>
Build the new Postgres 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.
</para>
</listitem>
<listitem>
<para>
Install the new Postgres binaries
</para>
<para>
Install the new server's binaries and support files. You can use the
same port numbers for both clusters, typically 5432, because the old and
new clusters will not be running at the same time.
</para>
<para>
For source installs, if you wish to install the new server in a custom
location, use 'prefix':
<programlisting>
gmake prefix=/usr/local/pgsql.new install
</programlisting>
</para>
</listitem>
<listitem>
<para>
Initialize the new PostgreSQL cluster
</para>
<para>
Initialize the new cluster using initdb. Again, use compatible initdb
flags that match the old cluster (pg_upgrade will check that too.) Many
prebuilt installers do this step automatically. There is no need to
start the new cluster.
</para>
<para>
If migrating EnterpriseDB's Postgres Plus Advanced Server, you must:
<itemizedlist>
<listitem>
<para>
<emphasis>not</> install <literal>sample tables and procedures/functions</>
in the new server
</para>
</listitem>
<listitem>
<para>
delete the empty <literal>edb</> schema in the <literal>enterprisedb</> database
</para>
</listitem>
<listitem>
<para>
copy dbserver/lib/pgmemcache.so from the old server
to the new server (AS8.3 to AS8.3R2 migrations only)
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
Install custom shared object files (or DLLs)
</para>
<para>
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.
pgcrypto.sql --- these will be migrated from the old cluster.
</para>
</listitem>
<listitem>
<para>
Adjust authentication
</para>
<para>
pg_upgrade will connect to the old and new servers several times,
so you might want to set authentication to <literal>trust</> in
<filename>pg_hba.conf</>, or if using <literal>md5</> authentication,
use a <filename>pgpass</> file to avoid being prompted repeatedly
for a password.
</para>
</listitem>
<listitem>
<para>
Stop both servers
</para>
<para>
Make sure both database servers are stopped using on Unix, e.g.:
<programlisting>
pg_ctl --pgdata /opt/PostgreSQL/8.4 stop
pg_ctl --pgdata /opt/PostgreSQL/8.5 stop
</programlisting>
or on Windows
<programlisting>
NET STOP postgresql-8.4
NET STOP postgresql-9.0
</programlisting>
or
<programlisting>
NET STOP pgsql-8.3 (different service name)
</programlisting>
</para>
</listitem>
<listitem>
<para>
Run pg_upgrade
Always run the pg_upgrade binary in the new server, not the old one.
pg_upgrade requires the specification of the old and new cluster's
PGDATA and executable (/bin) directories. You can also specify separate
user and port values, and whether you want the data linked instead of
copied (the default). If you use linking, the migration will be much
faster (no data copying), but you will no longer be able to access your
old cluster once you start the new cluster after the upgrade. See
pg_upgrade --help for a full list of options.
</para>
<para>
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:
<programlisting>
RUNAS /USER:postgres "CMD.EXE"
SET PATH=%PATH%;C:\Program Files\PostgreSQL\8.5\bin;
</programlisting>
and then run pg_upgrade with quoted directories, e.g.:
<programlisting>
pg_upgrade.exe
--old-datadir "C:/Program Files/PostgreSQL/8.4/data"
--new-datadir "C:/Program Files/PostgreSQL/8.5/data"
--old-bindir "C:/Program Files/PostgreSQL/8.4/bin"
--new-bindir "C:/Program Files/PostgreSQL/8.5/bin"
</programlisting>
Once started, pg_upgrade will verify the two clusters are compatible
and then do the migration. You can use pg_upgrade <option>--check</>
to perform only the checks, even if the old server is still
running. pg_upgrade <option>--check</> will also outline any
manual adjustments you will need to make after the migration.
</para>
<para>
Obviously, no one should be accessing the clusters during the migration.
</para>
<para>
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
#15 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 migration,
assuming the module is not being used to store user data.
</para>
</listitem>
<listitem>
<para>
Restore <filename>pg_hba.conf</>
</para>
<para>
If you modified <filename>pg_hba.conf</> to use <literal>trust</>,
restore its original authentication settings.
</para>
</listitem>
<listitem>
<para>
Post-Migration processing
</para>
<para>
If any post-migration 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-migration processing. Each script should be
run using:
<programlisting>
psql --username postgres --file script.sql postgres
</programlisting>
The scripts can be run in any order and can be deleted once they have
been run.
</para>
<para>
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.
</para>
</listitem>
<listitem>
<para>
Statistics
</para>
<para>
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 migration.
</para>
</listitem>
<listitem>
<para>
Delete old cluster
</para>
<para>
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. You will need to manually delete the old install
directories, e.g. /bin, /share.
</para>
</listitem>
<listitem>
<para>
Reverting to old cluster
</para>
<para>
If, after running pg_upgrade, you wish to revert to the old cluster,
there are several options.
</para>
<para>
If you ran pg_upgrade with <option>--check</>, no modifications
were made to the old cluster and you can re-use it anytime.
</para>
<para>
If you ran pg_upgrade with <option>--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.
</para>
<para>
If you ran pg_upgrade <emphasis>without</>_ <option>--link</>
or did not start the new server, the old cluster was not
modified except that an <literal>.old</> suffix was appended
to <filename>$PGDATA/global/pg_control</> and perhaps tablespace
directories. To reuse the old cluster, remove the ".old"
suffix from <filename>$PGDATA/global/pg_control</>. and, if
migrating to 8.4 or earlier, remove the tablespace directories
created by the migration and remove the ".old" suffix from
the tablespace directory names; then you can restart the old
cluster.
</para>
</listitem>
</orderedlist>
</sect2>
<sect2>
<title>Limitations In Migrating <emphasis>from</> PostgreSQL 8.3</title>
<para>
pg_upgrade will not work for a migration from 8.3 if a user column
is defined as:
<itemizedlist>
<listitem>
<para>
a <type>tsquery</> data type
</para>
</listitem>
<listitem>
<para>
data type <type>name</> and is not the first column
</para>
</listitem>
</itemizedlist>
</para>
<para>
You must drop any such columns and migrate them manually.
</para>
<para>
pg_upgrade will require a table rebuild if:
<itemizedlist>
<listitem>
<para>
a user column is of data type tsvector
</para>
</listitem>
</itemizedlist>
</para>
<para>
pg_upgrade will require a reindex if:
<itemizedlist>
<listitem>
<para>
an index is of type hash or gin
</para>
</listitem>
<listitem>
<para>
an index uses <function>bpchar_pattern_ops</>
</para>
</listitem>
</itemizedlist>
</para>
<para>
Also, the default datetime storage format changed to integer after
Postgres 8.3. pg_upgrade will check that the datetime storage format
used by the old and new clusters match. Make sure your new cluster is
built with the configure flag <option>--disable-integer-datetimes</>.
</para>
<para>
For Windows users, note that due to different integer datetimes settings
used by the one-click installer and the MSI installer, it is only
possible to upgrade from version 8.3 of the one-click distribution to
version 8.4 of the one-click distribution. It is not possible to upgrade
from the MSI installer to the one-click installer.
</para>
<para>
All failure, rebuild, and reindex cases will be reported by pg_upgrade
if they affect your installation; post-migration scripts to rebuild
tables and indexes will be automatically generated.
</para>
<para>
For deployment testing, create a schema-only copy of the old cluster,
insert dummy data, and migrate that.
</para>
<para>
If you want to use link mode and you don't want your old cluster
to be modified when the new cluster is started, make a copy of the
old cluster and migrate that with link mode. To make a valid copy
of the old cluster, use <application>rsync</> to create a dirty
copy of the old cluster while the server is running, then shut down
the old server and run rsync again to update the copy with any
changes to make it consistent.
</para>
</sect2>
</sect1>