PostgreSQL/クイックスタート

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This page is a translated version of the page PostgreSQL/QuickStart and the translation is 48% complete.

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これは、PostgreSQLのクイックスタートガイドです。 新しいPostgreSQLとその構成について説明します。 これは公式ドキュメントを補足するものですが、それに取って代わるものではありません。

はじめに

PostgreSQLについて少しだけ説明します

PostgreSQL はフリーでオープンソースのリレーショナル・データベース・管理システム(RDBMS; Relational Database Management System)です。PostgreSQLはトランザクション、シェマ、外部キーなどをサポートし、標準で商用も含めて他のいかなるデータベースよりもSQLスタンダードに追従し、セキュアであるとよく云われています。

より詳しい情報をお求めなら、postgresql.org のウェブサイトのページ About をご覧ください。

このアーティクルで説明すること

このアーティクルは Gentooに特化した PostgresSQL RDMS のインストールガイドです。

このアーティクルで使用する ebuild は dev-db/postgresql です。

このアーティクルでは、あなたが PostgreSQL の最新安定版をインストールするという仮定でお話しします。これを書いている時点でのバージョンは 9.3.5 ですが、あなたがインストールするバージョンに応じてコマンドを調整してください。

Ebuilds について

PostgreSQLはPortageのebuild機能でメジャーバージョンに基づいたスロットを提供しています。これにより、PostgreSQLの2つの主要バージョンを同時に動作させることができます。9.0-9.4のライブラリとサーバーを同時にインストールして使用することができます。これは、古いデータベースから新しいデータベースにデータを移動する必要がある場合、または本番データベースとテスト用データベースを同じマシンに配置する必要がある場合に役立ちます。また、これにより、データベース、対応するライブラリ、または実行可能ファイルが、互換性のない更新によって上書きされるのを防ぎます。このガイドで説明されている移行が必要になります。

さらに、マイナーバージョンアップで提供されているバグやセキュリティの修正は、データベースやPostgreSQLのインストール自体を破壊する恐れなしに適用することができます。9.3.4は互換性があることが保証されているため9.3.5に更新できます。9.3.4を出現させてサーバープロセスを再起動する以上の操作は不要です。移行、再構成、初期化は不要です。

詳細はPostgreSQLのバージョン管理方針を読んでください。

このアーティクルで説明しないこと

カバーされないことがかなりあります。 [1]は、2,000ページ近くのどこかにあります。 そのため、このクイックスタートガイドでは、多くの詳細を省略します。 Gentoo固有の問題といくつかの基本的な構成ガイドラインのみがカバーされます。

インストール

The Obsolete Ebuilds

If you have any of the following ebuilds installed, then you have an older, obsolete Gentoo installation of PostgreSQL and should migrate now: dev-db/postgresql-libs, dev-db/postgresql-client, dev-db/libpq, and dev-db/postgresql older than 9.0.

The split ebuilds dev-db/postgresql-docs, dev-db/postgresql-base, and/or dev-db/postgresql-server have been unified into a single package: dev-db/postgresql. Nothing is required for you to move from the split ebuilds to the unified ebuild other than to emerge the unified ebuild.

この記事では、古いebuildから新しいebuildへの移行について説明します。

USEフラグについて

USE flags for dev-db/postgresql PostgreSQL RDBMS

debug Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces
icu Enable ICU (Internationalization Components for Unicode) support, using dev-libs/icu
kerberos Add kerberos support
ldap Add LDAP support (Lightweight Directory Access Protocol)
libressl Use dev-libs/libressl instead of dev-libs/openssl when applicable (see also the ssl useflag)
llvm Add support for llvm JIT engine
nls Add Native Language Support (using gettextGNU locale utilities)
pam Add support for PAM (Pluggable Authentication Modules)DANGEROUS to arbitrarily flip
perl Add optional support/bindings for the Perl language
python Add optional support/bindings for the Python language
readline Enable support for libreadline, a GNU line-editing library that almost everyone wants
selinux !!internal use only!! Security Enhanced Linux support, this must be set by the selinux profile or breakage will occur
server Disable to build and install the clients and libraries only.
ssl Add support for SSL/TLS connections (Secure Socket Layer / Transport Layer Security)
static-libs Build static versions of dynamic libraries as well
systemd Enable use of systemd-specific libraries and features like socket activation or session tracking
tcl Add support the Tcl language
threads Add threads support for various packages. Usually pthreads
uuid Enable server side UUID generation (via dev-libs/ossp-uuid).
xml Add support for XML files
zlib Add support for zlib (de)compression

Information on relevant USE flags:

  • doc: Include the online documentation to be stored on your system
  • pg_legacytimestamp: Use the older, floating-point method for formatting timestamps instead of the higher resolution 64-bit integer method. Unless you had a previous installation that utilized this deprecated method, leave this USE flag disabled. Flipping 'pg_legacytimestamp' will require you to do a dump and restore if any of your databases utilize timestamps. The two methods are incompatible with each other.
  • readline: You really want this enabled. Disabling removes command line editing and history in psql.
  • selinux: This can only be enabled by using the SELinux profile.
  • uuid: Include support to generate a 128 bit random unique identifier. This is useful for merging databases together so the chances of collisions become extremely low.

Emerge しましょう

root #emerge --ask dev-db/postgresql
[ebuild N ] dev-db/postgresql-9.3.5 USE="doc -kerberos -ldap -pg_legacytimestamp
  nls perl python -pg_legacytimestamp (-selinux) readline ssl -tcl -threads
  -uuid -xml zlib" LINGUAS="-af -cs -de -es -fa -fr -hr -hu -it -ko -nb -pl
  -pt_BR -ro -ru -sk -sl -sv -tr -zh_CN -zh_TW" 0 kB

You may receive a notice regarding that any of the above packages are blocked by any or all of the following packages: dev-db/postgresql-libs, dev-db/postgresql-client, or dev-db/libpq. These packages are not maintained and obsoleted. Refer to the section on migration from the previous ebuilds to the new ones to know how to handle this situation.

データベース・クラスタの初期化の準備をしましょう

Once the packages have finished emerging, you may want to edit /etc/conf.d/postgresql-9.3. There are three lines that effect the defaults of the server and cannot be changed later without deleting the directory that contains the database cluster and reinitializing.

PGDATA defines where to place the configuration files. DATA_DIR defines where to create the database cluster and related files. PG_INITDB_OPTS may contain any extra options you would care to set. The extra options are not required as the reasonable defaults are, ahem, reasonable.

In the following example, PGDATA states that the configuration files are to be located in /etc/postgresql-9.3/ . DATA_DIR states that the database cluster should be installed to /var/lib/postgresql/9.3/data/ , which is the default. If you decide to stray from the default, bear in mind that it is a very good idea to keep the major version in the path. PG_INITDB_OPTS states that the default locale should be en_US.UTF-8 . That is, U.S. English ordering and formatting, and UTF-8 character encoding.

FILE /etc/conf.d/postgresql-9.3Example content
# Location of configuration files
PGDATA="/etc/postgresql-9.3/"
# Where the data directory is located/to be created
DATA_DIR="/var/lib/postgresql/9.3/data"
# Additional options to pass to initdb.
# See 'man initdb' for available options.
PG_INITDB_OPTS="--locale=en_US.UTF-8"


Note
This only determines the default locale and character encoding. You can specify different locales and/or character encodings at database creation time ( CREATE DATABASE ) in the same database cluster.

There are six locale options that can be set to override --locale= . The following table lists the six options that, if used, are to be formatted as: --option=lo_LO.ENCODING.

Option Effects
lc-collate String sort order
lc-ctype Character classification (What is a letter? Its upper-case equivalent?)
lc-messages Language of messages
lc-monetary Formatting of currency amounts
lc-numeric Formatting of numbers
lc-time Formatting of dates and times

したがって、デフォルトを英語にしたいが、たとえばスウェーデン語のメッセージが必要な場合、 PG_INITDB_OPTSは次のようになります。

CODE Setting PG_INITDB_OPTS
PG_INITDB_OPTS="--locale=en_US.UTF-8 --lc-messages=sv_SE.UTF-8"

A complete list of language and character encodings supported by the server can be found in the documentation, but your system must also support the respective languages and character encodings. Compare the output of locale -a to the encodings in the documentation.

You can change your locale and encoding selections at database creation time. In order to change the locale for a database after you have created it, you must drop the database and start over again.

root #emerge --config dev-db/postgresql:9.3

これにより、データベースクラスターが作成され、すべての関連サーバーファイルが PGDATAおよび DATA_DIRに格納されます。

設定

設定ファイルはどこにあるのでしょうか

Sample configuration files can be found in /usr/share/postgresql-9.3 (or whatever version), see the trouble shooting section for the script.

This time the focus is upon the files in the PGDATA directory, /etc/postgresql-9.3 , instead with primary focus on the postgresql.conf and pg_hba.conf files.

postgresql.conf

This is the main configuration file. The line that you may find of immediate interest is listen_addresses . This variable defines to which addresses PostgreSQL will bind. By default, only localhost and the Unix socket are bound. Changing listen_addresses is not enough to enable remote connections. That will be covered in the next section. The official documentation is fairly easy to understand and is exhaustive on all the settings available. It would behoove you to read that in addition to what is covered here as some things may change.

Of secondary interest is the logging destination. By default, everything is logged to postmaster.log in the DATA_DIR directory. There is an entire subsection of postgresql.conf that covers a slew of options for how, what and where to log. The subsection is marked: ERROR REPORTING AND LOGGING.

Other than listen_addresses and the logging options, the rest of the defaults in postgresql.conf are reasonable enough to get you going.

pg_hba.conf

pg_hba.confファイルは、誰がデータベースサーバへの接続を許可されているか、接続を確立するためにどの認証方法を使用しなければならないかを記述しています。繰り返しになりますが、ドキュメントには設定とその意味が網羅されていますが、明確にするためにいくつかのことをここでカバーしています。

FILE pg_hba.confDefault settings
# TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD
# 
# "local" is for Unix domain socket connections only
local   all         all                               trust
# IPv4 local connections:
host    all         all         127.0.0.1/32          trust
# IPv6 local connections:
host    all         all         ::1/128               trust

As has been mentioned before, by default the server is secure. Kind of. There is only one database role that is available for log in by default: postgres . And, the only way to initiate a connection to the database is through the /run/postgresql/.s.PGSQL.5432 Unix socket, which is owned by the postgres system user and system group, or via localhost. Now for the "kind of" bit: Any user on the system can make a connection to the database through the localhost. Even as the postgres database superuser.

Warning
Never disable the Unix socket entirely. The initscripts require access to it in order to operate properly. The method can be changed freely.

trustメソッドは、全てのユーザーがパスワードなしで任意のユーザーとしてログオンできるようにするものです。これは、それが暗示するものを指定しているだけです。指定されたデータベースへの指定されたタイプのすべての接続を、指定された場所から指定されたデータベースユーザ(システムユーザではない)からパスワードなしで指定されたデータベースへのすべての接続を信頼します。これにより、システム上の全てのユーザが最初からローカルホスト接続を介して任意のユーザとしてログオンできるようになります。これは見かけほど危険ではありませんが、ほとんどの状況で深刻なセキュリティリスクをもたらします。

最もよく使用する2つの方法は、 passwordmd5です。 passwordメソッドは、接続を開始するためにパスワードが必要であり、パスワードが「in-the-clear」で送信されることのみを指定します。 この方法は、Unixソケットやlocalhostを介して接続するなど、そのような情報がマシンから出てこない場合に適しています。 md5メソッドはパスワードに似ていますが、md5ハッシュを使用してパスワードを保護します。 これは、パスワードがネットワークを通過するときに使用したいものです。

At this point, this author would like to bring your attention to the last two lines, four lines including comments, of the pg_hba.conf file. PostgreSQL has native support for IPv6 regardless of your desires for such support. Additionally, IPv4 addresses are automatically mapped to IPv6 addresses, i.e. , 127.0.0.1 will be mapped to ::FFFF:127.0.0.1 and as "pure" IPv6 ::FFFF:7F00:0001.

ただし、ホスト名がIPアドレスにどのようにマップされるかについては、誤解があるようです。 /etc/hostsファイルを見てみましょう。

FILE /etc/hosts
# IPv4 and IPv6 localhost aliases
127.0.0.1       localhost
::1             localhost

From the example above you can see that both an IPv4 and an IPv6 IP address are mapped to localhost. When psql refers to this file, it will grab the first match and use that as the address; in this case 127.0.0.1. When PostgreSQL parses this, it will match the IPv6 formatted address as well, e.g. ::ffff:127.0.0.1. If, however, the IPv6 address appears first, then psql will map to ::1 alone; ::1 is not the same as ::ffff:127.0.0.1. As such, if you do not have ::1 as a permitted means of access, psql will not be able to establish a connection. Furthermore, your kernel needs to support the IPv6 protocol.

So, it is better to specify IP addresses alone to psql and in pg_hba.conf rather than to rely on /etc/hosts to be ordered properly, and it removes any doubt as to which IP addresses are allowed or to which server you will connect.

Starting the Server

Give It a Go!

Now start PostgreSQL and set the password for the database superuser postgres.

Change 'trust' to 'password' for the 'host' (not the 'local', Unix domain socket) connections.

root #nano -w /etc/postgresql-9.3/pg_hba.conf

Now start the database:

root #/etc/init.d/postgresql-9.3 start
postgresql-9.3  | * Starting PostgreSQL ...                             [ ok ]

サーバーへの接続を開き、パスワードを設定します:

root #psql -U postgres
psql (9.3.5)
Type "help" for help.
postgres=#\password
Enter new password:
Enter it again:
postgres=#\q

Change 'trust' to 'password' for the local connection:

root #nano -w /etc/postgresql-9.3/pg_hba.conf

次に、データベースに構成を再ロードさせます:

root #/etc/init.d/postgresql-9.3 reload
postgresql-9.3 | * Reloading PostgreSQL configuration ...               [ ok ]

Finally, once everything works as it should, have PostgreSQL start at boot:

root ## rc-update add postgresql-9.3 default
 * service postgresql-9.3 added to runlevel default

At this point you are ready to continue on with the official PostgreSQL Tutorial. The tutorial will guide you through creating roles, databases, schemata and all that fun and useful stuff.

Migrating PostgreSQL

When You Need to Migrate

移行を実行する必要がある理由は2つだけあります。あるメジャーバージョンから別のメジャーバージョンに移行する場合、たとえば、PostgreSQL 8.4.7から9.0.3に移行しますが、9.0.2から9.0.3には移行しません。 または、非推奨の浮動小数点タイムスタンプ形式から新しい64ビット整数タイムスタンプ形式に切り替える場合。

Note
You will need to migrate your database when you move from the obsolete ebuilds dev-db/libpq, dev-db/postgresql-libs, and dev-db/postgresql-client or dev-db/postgresql older than 9.0 to the new dev-db/postgresql ebuild.


Post-9.0 Migration

When upgrading from a previous version of the recent ebuilds, which is any version after 8.4, follow the beginning of this guide before proceeding with this migration.

pg_upgrade, a new utility that comes along with 9.0 and later, simplifies the migration process rather drastically.

However, there are two caveats with using pg_upgrade. Firstly, it does not support configuration files being in a different directory than where the data is stored. This can be resolved by using symbolic links. Lastly, you can only use it to migrate from a database from 8.3 or newer. If you have an older database you will need to follow the instructions to migrate from pre-9.0 deployments.

First ensure that the new database cluster is initialized (as described above). Then stop the servers you're going to migrate from and to:

root #/etc/init.d/postgresql-8.4 stop
root #/etc/init.d/postgresql-9.3 stop
root #ln -s /etc/postgresql-8.4/*.conf /var/lib/postgresql/8.4/data/
root #ln -s /etc/postgresql-9.3/*.conf /var/lib/postgresql/9.3/data/
Note
Symbolic links are already in place from version 9.4 onward.

利用可能なバージョンを確認してから、あなたのバージョンを選択してください:

root #eselect postgresql list
root #eselect postgresql set 9.3

Change the method of database user 'postgres' to trust on local connections on all databases:

root #nano -w /etc/postgresql-8.4/pg_hba.conf
root #nano -w /etc/postgresql-9.3/pg_hba.conf

You may need to change the permissions of /var/lib/postgresql/ before you perform the next step.

root #su - postgres
user $pg_upgrade -U postgres \

-d /var/lib/postgresql/8.4/data -D /var/lib/postgresql/9.3/data \

-b /usr/lib/postgresql-8.4/bin -B /usr/lib/postgresql-9.3/bin
Note
PostgreSQL prior to version 9.4 used the -u option instead of -U.

Perform the tasks pg_upgrade tells you to do, if any.

user $logout

これで完了です:

root #/etc/init.d/postgresql-9.3 start

Pre-9.0 Migration: With the New Ebuilds

Because the new ebuilds feature a more advanced slotting method than the previous ones, the downtime is quite minimal, most likely minutes rather than hours.

In the following examples, it is assumed that you are using the default locations and port settings, and that you are migrating from 8.3 to 8.4. Adjust accordingly if you have deviated from the default.

If you have not already done so, follow the installation instructions before starting the migration. Such a compile may hamper performance on the database server but it can keep going.

A couple of files need to be tweaked before beginning the migration. Edit PGPORT in the /etc/conf.d/postgresql-8.4 configuration file to 6543. (Any port number other than what your old installation is bound to will do.)

Next, edit /etc/postgresql-8.3/pg_hba.conf so that only the database superuser postgres can access the database cluster via the Unix socket.

root #cp -p /etc/postgresql-8.3/pg_hba.conf /etc/postgresql-8.4/

The following should be safe. Read the documentation to be sure.

root #cp -p /etc/postgresql-8.3/postgresql.conf /etc/postgresql-8.4/

Don't forget to copy over any other configuration files that you may need.

root #/etc/init.d/postgresql-8.3 reload
root #/etc/init.d/postgresql-8.4 start

Begin piping the data from the old cluster to the new cluster.

root #pg_dumpall -U postgres -p 5432 | psql -U postgres -d postgres -p 6543
root #/etc/init.d/postgresql-8.3 stop
root #/etc/init.d/postgresql-8.4 stop

Edit PGPORT back to 5432.

root #nano -w /etc/conf.d/postgresql-8.4

ユーザーにもう一度アクセスを許可します。

root #nano -w /etc/postgresql-8.4/pg_hba.conf
root #/etc/init.d/postgresql-8.4 start
root #rc-update del postgresql-8.3 && rc-update add postgresql-8.4 default

Hopefully everything went according to plan and you have a successfully updated server that contains precisely the same data, bit for bit, as the old server.

Pre-9.0 Migration: From the Obsolete Ebuilds

サーバーのダウンタイムを予定する必要があります。古い ebuilds は新しい ebuilds と同時にインストールすることはできません。そのため、サーバーを数時間ダウンさせなければならないことを想定してください。もしかしたら週末になるかもしれません。

Before starting, you will need to deny access to the server, so that no changes are made. You may also want to backup your postgresql.conf and pg_hba.conf and any other configuration file that you deem important.

root #pg_dumpall -U postgres > backup_file
root #/etc/init.d/postgresql stop
root #emerge -C dev-db/libpq dev-db/postgresql-client dev-db/postgresql-libs

Follow the steps detailed in this article for installing and configuring the server.

root #/etc/init.d/postgresql-8.4 start
root #psql -f backup_file postgres

You may break some packages that were built against those packages, but once you have installed dev-db/postgresql you can run revdep-rebuild to reemerge any packages that may have been broken.

ユーティリティー

pgAdmin

pgAdminは、PostgreSQLを管理するためのグラフィカルなユーティリティです。

トラブルシューティング

Server Lacks Instrumentation Functions

This problem is easy to solve, with the solution depending on the version you are using. What is difficult about it is finding the answer. What is required is an import from a file that already exists on the storage drive: adminpack.sql . To resolve this issue, run one of the following commands appropriate to the version you have.

For PostgreSQL 9.0 and earlier:

user $psql -U postgres --file /usr/share/postgresql-9.0/contrib/adminpack.sql

For PostgreSQL 9.1 and later:

user $psql -U postgres -c "CREATE EXTENSION adminpack;"

Missing config files in /etc/postgresql-9.x and /var/lib/postgresql/9.x/data

You can try to move the config files into the directory, where x is your postgresql version number, as follows:

root #cp /var/lib/postgresql/9.x/data/*.conf /etc/postgresql-9.x/

If those files are missing you will need to initialize them.

最初にpostgresのユーザにsuします:

root #su postgres

Then, as the postgres user, run initdb and specify the data directory:

user $initdb -D /var/lib/postgresql/9.x/data/

This will generate your configuration files and allow you to copy them over to /etc/postgresql-9.x/ as shown in the first command in this section.

"ERROR: timezone directory stack overflow" or "FATAL: too many private dirs demanded"

これはシンボリックリンクループが原因です。これを修正するには、以下のように入力します:

root #rm /usr/share/zoneinfo/posix

zoneinfo を更新するとこのシンボリックリンクが再作成されるので、再度削除する必要があることに注意してください。

Systemd

Force the service to start on bootup:

root #systemctl enable postgresql-9.4

To start service immediately:

root #systemctl start postgresql-9.4

If an error occurs check if the /run/postgresql/ directory is there. If not, then create it like so:

root #systemd-tmpfiles --create

Check the config file permissions:

root #ls -l /etc/postgresql-9.*/*
root #chown postgres:postgres /etc/postgresql-9.*/*
root #chmod 600 /etc/postgresql-9.*/*

Service file and changes to it

Systemd service files (postgresql-@SLOT@-.service) can be found in /lib/systemd/system/:

example config change:

FILE /lib/systemd/system/postgresql-@SLOT@.serviceExample config port change
[Service]
Environment=PGPORT=5433

This will override the setting appearing in /lib/systemd/system/postgresql-@SLOT@.service.

(source: postgresql-10.service file)

RemoveIPC

PostgreSQL recommends in wiki.postgresql.org/wiki/Systemd to change the RemoveIPC setting to no in /etc/systemd/logind.conf:

FILE /etc/systemd/logind.confRemoveIPC
RemoveIPC=no

(source: wiki.postgresql.org/wiki/Systemd)



This page is based on a document formerly found on our main website gentoo.org.
The following people contributed to the original document: Aaron W. Swenson,Mikkel A. Clausen
They are listed here because wiki history does not allow for any external attribution. If you edit the wiki article, please do not add yourself here; your contributions are recorded on each article's associated history page.