table of contents
| OID2NAME(1) | PostgreSQL 16.4 Documentation | OID2NAME(1) |
NAME¶
oid2name - resolve OIDs and file nodes in a PostgreSQL data directory
SYNOPSIS¶
oid2name [option...]
DESCRIPTION¶
oid2name 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 Chapter 73.
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!
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.
OPTIONS¶
oid2name accepts the following command-line arguments:
-f filenode
--filenode=filenode
-i
--indexes
-o oid
--oid=oid
-q
--quiet
-s
--tablespaces
-S
--system-objects
-t tablename_pattern
--table=tablename_pattern
-V
--version
-x
--extended
-?
--help
oid2name also accepts the following command-line arguments for connection parameters:
-d database
--dbname=database
-h host
--host=host
-H host
-p port
--port=port
-U username
--username=username
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.
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.
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.
ENVIRONMENT¶
PGHOST
PGPORT
PGUSER
This utility, like most other PostgreSQL utilities, also uses the environment variables supported by libpq (see Section 34.15).
The environment variable PG_COLOR specifies whether to use color in diagnostic messages. Possible values are always, auto and never.
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.
EXAMPLES¶
$ # 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
AUTHOR¶
B. Palmer <bpalmer@crimelabs.net>
| 2024 | PostgreSQL 16.4 |