$ grep postgresql /var/lib/dpkg/status
Source: postgresql-9.1
Original-Maintainer: Debian PostgreSQL Maintainers <pkg-postgresql-public@lists.alioth.debian.org>
Homepage: http://www.postgresql.org/
Package: postgresql-client-9.1
Source: postgresql-9.1
Replaces: postgresql-9.1 (<< 9.1.9-1ubuntu1)
Provides: postgresql-client
Depends: libc6 (>= 2.14), libedit2 (>= 2.11-20080614-1), libpq5 (>= 9.0~), libssl1.0.0 (>= 1.0.0), zlib1g (>= 1:1.1.4), postgresql-client-common (>= 115~)
Suggests: postgresql-9.1, postgresql-doc-9.1
Breaks: postgresql-9.1 (<< 9.1.9-1ubuntu1)
Conflicts: postgresql (<< 7.5)
 postgresql-9.1, too. On a network, you can install this package on
Original-Maintainer: Debian PostgreSQL Maintainers <pkg-postgresql-public@lists.alioth.debian.org>
Homepage: http://www.postgresql.org/
Suggests: librdf-storage-postgresql, librdf-storage-mysql, librdf-storage-sqlite, redland-utils
 backed storages, the librdf-storage-postgresql, librdf-storage-mysql
Package: postgresql-client-common
Source: postgresql-common
 /etc/postgresql-common/user_clusters 8ead7d1c74fba568815c1b4fd669c94e
 The postgresql-client-common package provides a structure under which
 option, an environment variable, /etc/postgresql-common/user_clusters,
 or ~/.postgresqlrc).
Original-Maintainer: Debian PostgreSQL Maintainers <pkg-postgresql-public@lists.alioth.debian.org>
Source: postgresql-9.1
Replaces: postgresql-dev
Suggests: postgresql-doc-9.1
Conflicts: postgresql-dev (<< 7.5)
Original-Maintainer: Debian PostgreSQL Maintainers <pkg-postgresql-public@lists.alioth.debian.org>
Homepage: http://www.postgresql.org/
Breaks: postgresql-common (<= 126)
Suggests: libmyodbc | odbc-postgresql | libsqliteodbc | tdsodbc | mdbtools, libmysql-java | libpg-java | libjtds-java, libreoffice-gcj, libreoffice-report-builder, unixodbc
  * libmyodbc | odbc-postgresql | libsqliteodbc | tdsodbc | mdbtools: ODBC
Package: postgresql-9.1
Replaces: postgresql-contrib-9.1 (<< 9.1~beta1-3~), postgresql-plpython-9.1 (<< 9.1.9-1ubuntu1)
Depends: libc6 (>= 2.15), libcomerr2 (>= 1.01), libgssapi-krb5-2 (>= 1.8+dfsg), libkrb5-3 (>= 1.6.dfsg.2), libldap-2.4-2 (>= 2.4.7), libpam0g (>= 0.99.7.1), libpq5 (>= 9.1~), libssl1.0.0 (>= 1.0.0), libxml2 (>= 2.7.4), postgresql-client-9.1, postgresql-common (>= 115~), tzdata, ssl-cert, locales
Breaks: postgresql-plpython-9.1 (<< 9.1.9-1ubuntu1)
Conflicts: postgresql (<< 7.5)
 are coordinated by the postgresql-common package. A package providing
Original-Maintainer: Debian PostgreSQL Maintainers <pkg-postgresql-public@lists.alioth.debian.org>
Homepage: http://www.postgresql.org/
Package: postgresql-common
Depends: postgresql-client-common (>= 140), procps, adduser, debconf (>= 0.5.00) | debconf-2.0, lsb-base (>= 3.0-3), ssl-cert (>= 1.0.11), logrotate (>= 3.8)
Breaks: postgresql-9.1 (<< 9.1.1-3~)
Conflicts: postgresql-7.4, postgresql-8.0
 /etc/init.d/postgresql 7fde8b7bd398a12f4a5ad88c0357ba42
 /etc/sysctl.d/30-postgresql-shm.conf 8fd97ec526f6110ba94ac1e6e7036b2a
 /etc/logrotate.d/postgresql-common 101326ef5d138998692ece35109ef1a2
 The postgresql-common package provides a structure under which
Original-Maintainer: Debian PostgreSQL Maintainers <pkg-postgresql-public@lists.alioth.debian.org>
Breaks: cli-uno-bridge (<< 1:3.0.0~dev300m22), hunspell-ar (<< 0.0.0+20080110-1.1), hunspell-da (<< 1:3.1.0-3), hunspell-de-at (<< 20071211-2), hunspell-de-ch (<< 20071211-2), hunspell-de-de (<< 20071211-2), hunspell-de-med (<< 20090825-1), hunspell-en-ca (<< 1:3.1.0-3), hunspell-en-us (<< 20070829-3), hunspell-fr (<< 1:3.1.0-3), hunspell-gl-es (<< 2.2a-6), hunspell-hu (<< 1:3.1.0-3), hunspell-ko (<< 0.3.3-1), hunspell-ne (<< 1:3.1.0-3), hunspell-se (<< 1.0~beta6.20081222-1.1), hunspell-sh (<< 1:3.1.0-3), hunspell-sr (<< 1:3.1.0-3), hunspell-uz (<< 0.6-3.1), hunspell-vi (<< 1:3.1.0-3), libcairo2 (= 1.4.8-1), libicu38 (= 3.8~d01-1), libreoffice-base (<< 1:4.0.2-0ubuntu1), libreoffice-calc (<< 1:4.0.2-0ubuntu1), libreoffice-common (<< 1:3.6.1~rc1), libreoffice-dev (<< 1:4.0.2-0ubuntu1), libreoffice-draw (<< 1:4.0.2-0ubuntu1), libreoffice-evolution (<< 1:4.0.2-0ubuntu1), libreoffice-gnome (<< 1:4.0.2-0ubuntu1), libreoffice-gtk (<< 1:4.0.2-0ubuntu1), libreoffice-impress (<< 1:4.0.2-0ubuntu1), libreoffice-kab (<< 1:3.4.1~), libreoffice-kde (<< 1:4.0.2-0ubuntu1), libreoffice-officebean (<< 1:4.0.2-0ubuntu1), libreoffice-sdbc-postgresql (<< 0.8.1~), libreoffice-style-andromeda (<< 1:3.3.0-1), libreoffice-style-crystal (<< 1:3.3.0-1), libreoffice-style-galaxy (<< 1:3.3.0-1), libreoffice-style-hicontrast (<< 1:3.3.0-1), libreoffice-style-oxygen (<< 1:3.3.0-1), libreoffice-style-tango (<< 1:3.3.0-1), libreoffice-writer (<< 1:4.0.2-0ubuntu1), mozilla-libreoffice (<< 1:3.5.0~beta~), mozilla-plugin-vlc (<< 1.0), myspell-af (<< 1:3.1.0-3), myspell-ca (<< 0.6-8), myspell-cs-cz (<< 20040229-4.1), myspell-da (<< 1.6.18-1.1), myspell-de-at (<< 20071211-2), myspell-de-ch (<< 20071211-2), myspell-de-de (<< 20071211-2), myspell-de-de-oldspell (<< 1:2-25.1), myspell-el-gr (<< 0.3-1.1), myspell-en-au (<< 2.1-5), myspell-en-gb (<< 1:3.1.0-3), myspell-en-us (<< 1:3.1.0-3), myspell-en-za (<< 1:3.1.0-3), myspell-eo (<< 2.1.2000.02.25-41), myspell-es (<< 1.10-7), myspell-et (<< 1:20030606-12.1), myspell-fa (<< 0.20070816-2), myspell-fi (<< 0.7-17.2), myspell-fo (<< 0.2.36-3), myspell-fr (<< 1.4-25), myspell-fr-gut (<< 1:1.0-26.1), myspell-ga (<< 2.0-19), myspell-gd (<< 0.50-7), myspell-gv (<< 0.50-8), myspell-hr (<< 20060617-2), myspell-hu (<< 0.99.4-1.2), myspell-hy (<< 0.10.1-1.1), myspell-it (<< 1:3.1.0-3), myspell-ku (<< 0.20.0-1.1), myspell-lv (<< 0.7.3-3.1), myspell-nb (<< 2.0.10-3.1), myspell-ne (<< 1.0-4.1), myspell-nl (<< 1:1.10-3), myspell-nn (<< 2.0.10-3.1), myspell-pl (<< 20090830-1), myspell-pt-br (<< 2009.03.30-1.1), myspell-pt-pt (<< 20090309-1.1), myspell-ru (<< 0.99g5-8.1), myspell-sk (<< 0.5.5a-2.1), myspell-sv-se (<< 1.3.8-6-2.2), myspell-sw (<< 1:3.1.0-3), myspell-th (<< 1:3.1.0-3), myspell-tl (<< 0.4-0-5)