From bf1c866597a0e59a30b13a66f3ae505655b61853 Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Mon, 25 Aug 2014 15:34:51 -0400 Subject: [PATCH] upgrade docs: highlight pg_upgrade, warn about globals preservation Also, remove OID preservation mention, mention non-text dump formats Backpatch through 9.4 --- doc/src/sgml/backup.sgml | 27 ++++++++++++---------- doc/src/sgml/runtime.sgml | 47 ++++++++++++++++++++++++--------------- 2 files changed, 44 insertions(+), 30 deletions(-) diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml index 06f064e1a6..07ca0dc62d 100644 --- a/doc/src/sgml/backup.sgml +++ b/doc/src/sgml/backup.sgml @@ -28,7 +28,7 @@ <acronym>SQL</> Dump - The idea behind this dump method is to generate a text file with SQL + The idea behind this dump method is to generate a file with SQL commands that, when fed back to the server, will recreate the database in the same state as it was at the time of the dump. PostgreSQL provides the utility program @@ -39,6 +39,9 @@ pg_dump dbname > As you see, pg_dump writes its result to the standard output. We will see below how this can be useful. + While the above command creates a text file, pg_dump + can create files in other formats that allow for parallism and more + fine-grained control of object restoration. @@ -98,20 +101,11 @@ pg_dump dbname > ALTER TABLE.) - - - If your database schema relies on OIDs (for instance, as foreign - keys) you must instruct pg_dump to dump the OIDs - as well. To do this, use the command-line - option. - - - Restoring the Dump - The text files created by pg_dump are intended to + Text files created by pg_dump are intended to be read in by the psql program. The general command form to restore a dump is @@ -127,6 +121,8 @@ psql dbname < pg_dump for specifying the database server to connect to and the user name to use. See the reference page for more information. + Non-text file dumps are restored using the utility. @@ -225,7 +221,14 @@ psql -f infile postgres roles, tablespaces, and empty databases, then invoking pg_dump for each database. This means that while each database will be internally consistent, the snapshots of - different databases might not be exactly in-sync. + different databases are not sychronized. + + + + Cluster-wide data can be dumped alone using the + pg_dumpall diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml index 1d91d92fe3..f337485736 100644 --- a/doc/src/sgml/runtime.sgml +++ b/doc/src/sgml/runtime.sgml @@ -1517,8 +1517,9 @@ $ kill -INT `head -1 /usr/local/pgsql/data/postmaster.pid`major releases of PostgreSQL, the internal data storage format is subject to change, thus complicating upgrades. The traditional method for moving data to a new major version - is to dump and reload the database. Other methods are available, - as discussed below. + is to dump and reload the database, though this can be slow. A + faster method is . Replication methods are + also available, as discussed below. @@ -1593,12 +1594,14 @@ $ kill -INT `head -1 /usr/local/pgsql/data/postmaster.pid` - - Upgrading Data via <application>pg_dump</> + + Upgrading Data via <application>pg_dumpall</> - To dump data from one major version of PostgreSQL and - reload it in another, you must use pg_dump; file system + One upgrade method is to dump data from one major version of + PostgreSQL and reload it in another — to do + this, you must use a logical backup tool like + pg_dumpall; file system level backup methods will not work. (There are checks in place that prevent you from using a data directory with an incompatible version of PostgreSQL, so no great harm can be done by @@ -1607,7 +1610,8 @@ $ kill -INT `head -1 /usr/local/pgsql/data/postmaster.pid` It is recommended that you use the pg_dump and - pg_dumpall programs from the newer version of + pg_dumpall programs from the newer + version of PostgreSQL, to take advantage of enhancements that might have been made in these programs. Current releases of the dump programs can read data from any server version back to 7.0. @@ -1642,14 +1646,12 @@ $ kill -INT `head -1 /usr/local/pgsql/data/postmaster.pid` pg_dumpall > outputfile - If you need to preserve OIDs (such as when using them as - foreign keys), then use the option when running - pg_dumpall. To make the backup, you can use the pg_dumpall - command from the version you are currently running. For best + command from the version you are currently running; see for more details. For best results, however, try to use the pg_dumpall command from PostgreSQL &version;, since this version contains bug fixes and improvements over older @@ -1683,7 +1685,8 @@ $ kill -INT `head -1 /usr/local/pgsql/data/postmaster.pid` If restoring from backup, rename or delete the old installation - directory. It is a good idea to rename the directory, rather than + directory if it is not version-specific. It is a good idea to + rename the directory, rather than delete it, in case you have trouble and need to revert to it. Keep in mind the directory might consume significant disk space. To rename the directory, use a command like this: @@ -1755,16 +1758,24 @@ pg_dumpall -p 5432 | psql -d postgres -p 5433 - - Non-Dump Upgrade Methods + + Upgrading Data via <application>pg_upgrade</> - The pg_upgrade module allows an - installation to be migrated in-place from one major - PostgreSQL version to the next. Upgrades can be - performed in minutes. + The module allows an installation to + be migrated in-place from one major PostgreSQL + version to another. Upgrades can be performed in minutes, + particularly with + + + + Upgrading Data via Replication + It is also possible to use certain replication methods, such as Slony, to create a standby server with the updated version of -- 2.40.0