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<!-- doc/src/sgml/oid2name.sgml -->
<refentry id="oid2name">
<indexterm zone="oid2name">
<primary>oid2name</primary>
</indexterm>
<refmeta>
<refentrytitle>oid2name</refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo>Application</refmiscinfo>
</refmeta>
<refnamediv>
<refname>oid2name</refname>
<refpurpose>resolve OIDs and file nodes in a <productname>PostgreSQL</productname> data directory</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>oid2name</command>
<arg rep="repeat"><replaceable>option</replaceable></arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<application>oid2name</application> is a utility program that helps administrators to
examine the file structure used by PostgreSQL. To make use of it, you need
to be familiar with the database file structure, which is described in
<xref linkend="storage"/>.
</para>
<note>
<para>
The name <quote>oid2name</quote> is historical, and is actually rather
misleading, since most of the time when you use it, you will really
be concerned with tables' filenode numbers (which are the file names
visible in the database directories). Be sure you understand the
difference between table OIDs and table filenodes!
</para>
</note>
<para>
<application>oid2name</application> connects to a target database and
extracts OID, filenode, and/or table name information. You can also have
it show database OIDs or tablespace OIDs.
</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>
<application>oid2name</application> accepts the following command-line arguments:
<variablelist>
<varlistentry>
<term><option>-f <replaceable class="parameter">filenode</replaceable></option></term>
<term><option>--filenode=<replaceable class="parameter">filenode</replaceable></option></term>
<listitem><para>show info for table with filenode <replaceable>filenode</replaceable>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-i</option></term>
<term><option>--indexes</option></term>
<listitem><para>include indexes and sequences in the listing.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-o <replaceable class="parameter">oid</replaceable></option></term>
<term><option>--oid=<replaceable class="parameter">oid</replaceable></option></term>
<listitem><para>show info for table with OID <replaceable>oid</replaceable>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-q</option></term>
<term><option>--quiet</option></term>
<listitem><para>omit headers (useful for scripting).</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-s</option></term>
<term><option>--tablespaces</option></term>
<listitem><para>show tablespace OIDs.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-S</option></term>
<term><option>--system-objects</option></term>
<listitem><para>include system objects (those in
<option>information_schema</option>, <option>pg_toast</option>
and <option>pg_catalog</option> schemas).
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-t <replaceable class="parameter">tablename_pattern</replaceable></option></term>
<term><option>--table=<replaceable class="parameter">tablename_pattern</replaceable></option></term>
<listitem><para>show info for table(s) matching <replaceable class="parameter">tablename_pattern</replaceable>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-V</option></term>
<term><option>--version</option></term>
<listitem>
<para>
Print the <application>oid2name</application> version and exit.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-x</option></term>
<term><option>--extended</option></term>
<listitem><para>display more information about each object shown: tablespace name,
schema name, and OID.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-?</option></term>
<term><option>--help</option></term>
<listitem>
<para>
Show help about <application>oid2name</application> command line
arguments, and exit.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
<para>
<application>oid2name</application> also accepts the following command-line
arguments for connection parameters:
<variablelist>
<varlistentry>
<term><option>-d <replaceable class="parameter">database</replaceable></option></term>
<term><option>--dbname=<replaceable class="parameter">database</replaceable></option></term>
<listitem><para>database to connect to.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-h <replaceable class="parameter">host</replaceable></option></term>
<term><option>--host=<replaceable class="parameter">host</replaceable></option></term>
<listitem><para>database server's host.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-H <replaceable class="parameter">host</replaceable></option></term>
<listitem><para>database server's host. Use of this parameter is
<emphasis>deprecated</emphasis> as of
<productname>PostgreSQL</productname> 12.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-p <replaceable class="parameter">port</replaceable></option></term>
<term><option>--port=<replaceable class="parameter">port</replaceable></option></term>
<listitem><para>database server's port.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-U <replaceable class="parameter">username</replaceable></option></term>
<term><option>--username=<replaceable class="parameter">username</replaceable></option></term>
<listitem><para>user name to connect as.</para></listitem>
</varlistentry>
</variablelist>
</para>
<para>
To display specific tables, select which tables to show by
using <option>-o</option>, <option>-f</option> and/or <option>-t</option>.
<option>-o</option> takes an OID,
<option>-f</option> takes a filenode,
and <option>-t</option> takes a table name (actually, it's a <literal>LIKE</literal>
pattern, so you can use things like <literal>foo%</literal>).
You can use as many
of these options as you like, and the listing will include all objects
matched by any of the options. But note that these options can only
show objects in the database given by <option>-d</option>.
</para>
<para>
If you don't give any of <option>-o</option>, <option>-f</option> or <option>-t</option>,
but do give <option>-d</option>, it will list all tables in the database
named by <option>-d</option>. In this mode, the <option>-S</option> and
<option>-i</option> options control what gets listed.
</para>
<para>
If you don't give <option>-d</option> either, it will show a listing of database
OIDs. Alternatively you can give <option>-s</option> to get a tablespace
listing.
</para>
</refsect1>
<refsect1>
<title>Environment</title>
<variablelist>
<varlistentry>
<term><envar>PGHOST</envar></term>
<term><envar>PGPORT</envar></term>
<term><envar>PGUSER</envar></term>
<listitem>
<para>
Default connection parameters.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
This utility, like most other <productname>PostgreSQL</productname>
utilities, also uses the environment variables supported by
<application>libpq</application> (see <xref linkend="libpq-envars"/>).
</para>
<para>
The environment variable <envar>PG_COLOR</envar> specifies whether to use
color in diagnostic messages. Possible values are
<literal>always</literal>, <literal>auto</literal> and
<literal>never</literal>.
</para>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
<application>oid2name</application> requires a running database server with
non-corrupt system catalogs. It is therefore of only limited use
for recovering from catastrophic database corruption situations.
</para>
</refsect1>
<refsect1>
<title>Examples</title>
<screen>
$ # what's in this database server, anyway?
$ oid2name
All databases:
Oid Database Name Tablespace
----------------------------------
17228 alvherre pg_default
17255 regression pg_default
17227 template0 pg_default
1 template1 pg_default
$ oid2name -s
All tablespaces:
Oid Tablespace Name
-------------------------
1663 pg_default
1664 pg_global
155151 fastdisk
155152 bigdisk
$ # OK, let's look into database alvherre
$ cd $PGDATA/base/17228
$ # get top 10 db objects in the default tablespace, ordered by size
$ ls -lS * | head -10
-rw------- 1 alvherre alvherre 136536064 sep 14 09:51 155173
-rw------- 1 alvherre alvherre 17965056 sep 14 09:51 1155291
-rw------- 1 alvherre alvherre 1204224 sep 14 09:51 16717
-rw------- 1 alvherre alvherre 581632 sep 6 17:51 1255
-rw------- 1 alvherre alvherre 237568 sep 14 09:50 16674
-rw------- 1 alvherre alvherre 212992 sep 14 09:51 1249
-rw------- 1 alvherre alvherre 204800 sep 14 09:51 16684
-rw------- 1 alvherre alvherre 196608 sep 14 09:50 16700
-rw------- 1 alvherre alvherre 163840 sep 14 09:50 16699
-rw------- 1 alvherre alvherre 122880 sep 6 17:51 16751
$ # I wonder what file 155173 is ...
$ oid2name -d alvherre -f 155173
From database "alvherre":
Filenode Table Name
----------------------
155173 accounts
$ # you can ask for more than one object
$ oid2name -d alvherre -f 155173 -f 1155291
From database "alvherre":
Filenode Table Name
-------------------------
155173 accounts
1155291 accounts_pkey
$ # you can mix the options, and get more details with -x
$ oid2name -d alvherre -t accounts -f 1155291 -x
From database "alvherre":
Filenode Table Name Oid Schema Tablespace
------------------------------------------------------
155173 accounts 155173 public pg_default
1155291 accounts_pkey 1155291 public pg_default
$ # show disk space for every db object
$ du [0-9]* |
> while read SIZE FILENODE
> do
> echo "$SIZE `oid2name -q -d alvherre -i -f $FILENODE`"
> done
16 1155287 branches_pkey
16 1155289 tellers_pkey
17561 1155291 accounts_pkey
...
$ # same, but sort by size
$ du [0-9]* | sort -rn | while read SIZE FN
> do
> echo "$SIZE `oid2name -q -d alvherre -f $FN`"
> done
133466 155173 accounts
17561 1155291 accounts_pkey
1177 16717 pg_proc_proname_args_nsp_index
...
$ # If you want to see what's in tablespaces, use the pg_tblspc directory
$ cd $PGDATA/pg_tblspc
$ oid2name -s
All tablespaces:
Oid Tablespace Name
-------------------------
1663 pg_default
1664 pg_global
155151 fastdisk
155152 bigdisk
$ # what databases have objects in tablespace "fastdisk"?
$ ls -d 155151/*
155151/17228/ 155151/PG_VERSION
$ # Oh, what was database 17228 again?
$ oid2name
All databases:
Oid Database Name Tablespace
----------------------------------
17228 alvherre pg_default
17255 regression pg_default
17227 template0 pg_default
1 template1 pg_default
$ # Let's see what objects does this database have in the tablespace.
$ cd 155151/17228
$ ls -l
total 0
-rw------- 1 postgres postgres 0 sep 13 23:20 155156
$ # OK, this is a pretty small table ... but which one is it?
$ oid2name -d alvherre -f 155156
From database "alvherre":
Filenode Table Name
----------------------
155156 foo
</screen>
</refsect1>
<refsect1>
<title>Author</title>
<para>
B. Palmer <email>bpalmer@crimelabs.net</email>
</para>
</refsect1>
</refentry>