OID2NAME(1)

💅 OID2NAME(1) — the little data-directory detective 🕵️♀️✨

okay so this is oid2name from PostgreSQL 15.19, bestie — and yes, the manual name is literally right there in the title, we're not doing the boring header line, we're doing vibes. 🎀

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✨ NAME ✨

oid2name — resolve OIDs and file nodes in a PostgreSQL data directory. no cap, that's the whole assignment. 🌈

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🌸 SYNOPSIS 🌸

oid2name [option...]

literally just the command and some options, she's lowkey simple like that. 💅

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🦋 DESCRIPTION 🦋

okay so oid2name is a utility program that helps administrators 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 Chapter 73. iykyk. 📚

⚠️ Note: the name “oid2name” 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! this is the part where you don't confuse the two, bestie, fr fr. 😭💀

oid2name 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. it's giving "swiss army knife but make it postgres." 🔥

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🎀 OPTIONS 🎀

oid2name accepts the following command-line arguments:

• -f filenode, --filenode=filenode — show info for table with filenode filenode. that's the file number, not the OID, okay? 🫶
• -i, --indexes — include indexes and sequences in the listing. yes queen, show us everything. ✨
• -o oid, --oid=oid — show info for table with OID oid. the actual object ID this time. 💖
• -q, --quiet — omit headers (useful for scripting). perfect for when you're piping into stuff and don't want the extra chatter. 🤫
• -s, --tablespaces — show tablespace OIDs. tablespace girlies rise. 🌸
• -S, --system-objects — include system objects (those in information_schema, pg_toast and pg_catalog schemas). system stuff, very "behind the scenes." 🧚
• -t tablename_pattern, --table=tablename_pattern — show info for table(s) matching tablename_pattern. it's a pattern, so you can get spicy with it. 💅
• -V, --version — Print the oid2name version and exit. short and sweet. ✅
• -x, --extended — display more information about each object shown: tablespace name, schema name, and OID. the deluxe edition, periodt. 👑
• -?, --help — Show help about oid2name command line arguments, and exit. when in doubt, ask for help. 🫶

oid2name also accepts the following command-line arguments for connection parameters:

• -d database, --dbname=database — database to connect to. pick your database, bestie. 🗂️
• -h host, --host=host — database server's host. where's the server at? 🌐
• -H host — database server's host. Use of this parameter is deprecated as of PostgreSQL 12. 🚨 like, don't use it unless you have to. 💀
• -p port, --port=port — database server's port. the door number, basically. 🚪
• -U username, --username=username — user name to connect as. who are you today? 🪪

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okay so real talk: to display specific tables, select which tables to show by using -o, -f and/or -t. -o takes an OID, -f takes a filenode, and -t takes a table name (actually, it's a LIKE pattern, so you can use things like foo%). 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 -d. don't forget the -d, she's kind of important. 😭

if you don't give any of -o, -f or -t, but do give -d, it will list all tables in the database named by -d. in this mode, the -S and -i options control what gets listed. so -S and -i are the vibe checkers here. ✨

if you don't give -d either, it will show a listing of database OIDs. alternatively you can give -s to get a tablespace listing. easy peasy. 💖

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🌈 ENVIRONMENT 🌈

• PGHOST
• PGPORT
• PGUSER

those are the default connection parameters. the usual suspects. 🫶

this utility, like most other PostgreSQL utilities, also uses the environment variables supported by libpq (see Section 34.15). libpq is doing a lot of heavy lifting behind the scenes, ngl. 📚

the environment variable PG_COLOR specifies whether to use color in diagnostic messages. possible values are always, auto and never. choose your color adventure. 🎨✨

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💜 NOTES 💜

oid2name requires a running database server with non-corrupt system catalogs. it is therefore of only limited use for recovering from catastrophic database corruption situations. like, she's not a miracle worker, bestie — catastrophic corruption is a whole different beast. 😭💀

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🍓 EXAMPLES 🍓

okay these examples are a whole vibe, and you should copy them exactly:

        $ # 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

iconic. no notes. 💅✨

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👑 AUTHOR 👑

B. Palmer <bpalmer@crimelabs.net> the original icon behind this whole thing. 🫶

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okay that's the whole page, bestie — from PostgreSQL 15.19, dated 2026, filed under OID2NAME(1). mwah 💋✨ go resolve some OIDs and slay. 🌈💖