vacuumdb — 지정한 PostgreSQL 데이터베이스를 청소하고 통계 정보를 갱신한다.
vacuumdb
[접속옵션
...] [옵션
...]
[
-t
| --table
테이블
[( 칼럼
[,...] )]
]
... [디비이름
]
vacuumdb
[접속옵션
...] [옵션
...] -a
| --all
vacuumdb 명령은 지정한 PostgreSQL 데이터베이스를 청소하고, 아울러 쿼리 최적화에서 쓰일 내부 통계 정보를 만든다.
vacuumdb 명령은 내부적으로 서버에 접속해서 VACUUM SQL 명령을 실행하는 응용 프로그램이다. There is no effective difference between vacuuming and analyzing databases via this utility and via other methods for accessing the server.
그래서, 이 명령 사용 설명서를 우리말로 옮기는 작업은 더 이상 진행하지 않는다. - 옮긴이
vacuumdb accepts the following command-line arguments:
-a
--all
Vacuum all databases.
[-d] dbname
[--dbname=]dbname
Specifies the name of the database to be cleaned or analyzed,
when -a
/--all
is not used.
If this is not specified, the database name is read
from the environment variable PGDATABASE
. If
that is not set, the user name specified for the connection is
used. The dbname
can be a connection string. If so,
connection string parameters will override any conflicting command
line options.
--disable-page-skipping
Disable skipping pages based on the contents of the visibility map.
This option is only available for servers running PostgreSQL 9.6 and later.
-e
--echo
Echo the commands that vacuumdb generates and sends to the server.
-f
--full
Perform “full” vacuuming.
-F
--freeze
Aggressively “freeze” tuples.
-j njobs
--jobs=njobs
Execute the vacuum or analyze commands in parallel by running
njobs
commands simultaneously. This option may reduce the processing time
but it also increases the load on the database server.
vacuumdb will open
njobs
connections to the
database, so make sure your max_connections
setting is high enough to accommodate all connections.
Note that using this mode together with the -f
(FULL
) option might cause deadlock failures if
certain system catalogs are processed in parallel.
--min-mxid-age mxid_age
Only execute the vacuum or analyze commands on tables with a multixact
ID age of at least mxid_age
.
This setting is useful for prioritizing tables to process to prevent
multixact ID wraparound (see
24.1.5.1절).
For the purposes of this option, the multixact ID age of a relation is the greatest of the ages of the main relation and its associated TOAST table, if one exists. Since the commands issued by vacuumdb will also process the TOAST table for the relation if necessary, it does not need to be considered separately.
This option is only available for servers running PostgreSQL 9.6 and later.
--min-xid-age xid_age
Only execute the vacuum or analyze commands on tables with a
transaction ID age of at least
xid_age
. This setting
is useful for prioritizing tables to process to prevent transaction
ID wraparound (see 24.1.5절).
For the purposes of this option, the transaction ID age of a relation is the greatest of the ages of the main relation and its associated TOAST table, if one exists. Since the commands issued by vacuumdb will also process the TOAST table for the relation if necessary, it does not need to be considered separately.
This option is only available for servers running PostgreSQL 9.6 and later.
-P parallel_degree
--parallel=parallel_degree
Specify the parallel degree of parallel vacuum. This allows the vacuum to leverage multiple CPUs to process indexes. See VACUUM.
This option is only available for servers running PostgreSQL 13 and later.
-q
--quiet
Do not display progress messages.
--skip-locked
Skip relations that cannot be immediately locked for processing.
This option is only available for servers running PostgreSQL 12 and later.
-t table
[ (column
[,...]) ]
--table=table
[ (column
[,...]) ]
Clean or analyze table
only.
Column names can be specified only in conjunction with
the --analyze
or --analyze-only
options.
Multiple tables can be vacuumed by writing multiple
-t
switches.
If you specify columns, you probably have to escape the parentheses from the shell. (See examples below.)
-v
--verbose
Print detailed information during processing.
-V
--version
Print the vacuumdb version and exit.
-z
--analyze
Also calculate statistics for use by the optimizer.
-Z
--analyze-only
Only calculate statistics for use by the optimizer (no vacuum).
--analyze-in-stages
Only calculate statistics for use by the optimizer (no vacuum),
like --analyze-only
. Run several (currently three)
stages of analyze with different configuration settings, to produce
usable statistics faster.
This option is useful to analyze a database that was newly populated
from a restored dump or by pg_upgrade
. This option
will try to create some statistics as fast as possible, to make the
database usable, and then produce full statistics in the subsequent
stages.
-?
--help
Show help about vacuumdb command line arguments, and exit.
vacuumdb also accepts the following command-line arguments for connection parameters:
-h host
--host=host
Specifies the host name of the machine on which the server is running. If the value begins with a slash, it is used as the directory for the Unix domain socket.
-p port
--port=port
Specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections.
-U username
--username=username
User name to connect as.
-w
--no-password
Never issue a password prompt. If the server requires
password authentication and a password is not available by
other means such as a .pgpass
file, the
connection attempt will fail. This option can be useful in
batch jobs and scripts where no user is present to enter a
password.
-W
--password
Force vacuumdb to prompt for a password before connecting to a database.
This option is never essential, since
vacuumdb will automatically prompt
for a password if the server demands password authentication.
However, vacuumdb will waste a
connection attempt finding out that the server wants a password.
In some cases it is worth typing -W
to avoid the extra
connection attempt.
--maintenance-db=dbname
Specifies the name of the database to connect to to discover which
databases should be vacuumed,
when -a
/--all
is used.
If not specified, the postgres
database will be used,
or if that does not exist, template1
will be used.
This can be a connection
string. If so, connection string parameters will override any
conflicting command line options. Also, connection string parameters
other than the database name itself will be re-used when connecting
to other databases.
PGDATABASE
PGHOST
PGPORT
PGUSER
Default connection parameters
PG_COLOR
Specifies whether to use color in diagnostic messages. Possible values
are always
, auto
and
never
.
This utility, like most other PostgreSQL utilities, also uses the environment variables supported by libpq (see 33.14절).
In case of difficulty, see VACUUM and psql for discussions of potential problems and error messages. The database server must be running at the targeted host. Also, any default connection settings and environment variables used by the libpq front-end library will apply.
vacuumdb might need to connect several
times to the PostgreSQL server, asking
for a password each time. It is convenient to have a
~/.pgpass
file in such cases. See 33.15절 for more information.
To clean the database test
:
$
vacuumdb test
To clean and analyze for the optimizer a database named
bigdb
:
$
vacuumdb --analyze bigdb
To clean a single table
foo
in a database named
xyzzy
, and analyze a single column
bar
of the table for the optimizer:
$
vacuumdb --analyze --verbose --table='foo(bar)' xyzzy