lt_initdb

lt_initdb — initdb package, create a new LightDB database cluster

Synopsis

lt_initdb [option...] [ --pgdata | -D ] directory

Description

lt_initdb initdb package, creates a new LightDB database cluster. A database cluster is a collection of databases that are managed by a single server instance.

Options

-A authmethod
--auth=authmethod

This option specifies the default authentication method for local users used in lt_hba.conf (host and local lines). initdb will prepopulate lt_hba.conf entries using the specified authentication method for non-replication as well as replication connections.

Do not use trust unless you trust all local users on your system. trust is the default for ease of installation.

--auth-host=authmethod

This option specifies the authentication method for local users via TCP/IP connections used in lt_hba.conf (host lines).

--auth-local=authmethod

This option specifies the authentication method for local users via Unix-domain socket connections used in lt_hba.conf (local lines).

-p port

This option specifies the port for the database cluster. The default port is 5432.

-D directory
--pgdata=directory

This option specifies the directory where the database cluster should be stored. This is the only information required by initdb, but you can avoid writing it by setting the LTDATA environment variable, which can be convenient since the database server (lightdb) can find the database directory later by the same variable.

-E encoding
--encoding=encoding

Selects the encoding of the template database. This will also be the default encoding of any database you create later, unless you override it there. The default is derived from the locale, or SQL_ASCII if that does not work. The character sets supported by the LightDB server are described in Section 21.3.1.

-g
--allow-group-access

Allows users in the same group as the cluster owner to read all cluster files created by initdb. This option is ignored on Windows as it does not support POSIX-style group permissions.

-u
--upgrade-mode

Create a database cluster without extensions, which is equivalent to using initdb directly.

-k
--data-checksums

Use checksums on data pages to help detect corruption by the I/O system that would otherwise be silent. Enabling checksums may incur a noticeable performance penalty. If set, checksums are calculated for all objects, in all databases. All checksum failures will be reported in the pg_stat_database view.

-K
--encryption-key-command

Used for Transparent Data Encryption. Before creating your database instance, you have to write some code to make sure that the key can be read by the database during startup and instance creation. The key is a 32-byte hex string.

Here is the most simplistic example possible:

    cat /somewhere/provide_key.sh
    #!/bin/sh
    echo 882fb7c12e80280fd664c69d2d636913
       

All you need is a program that prints the key to stdout. Make sure that LightDB is able to execute this program:

    chmod +x /somewhere/provide_key.sh
       

Note: You don't have to write a shell script – you can use any kind of executable such as a C, Go or Python.

Create the database instance:

    lt_initdb -p 5432 -D ./data -K /somewhere/provide_key.sh
       
--locale=locale

Sets the default locale for the database cluster. If this option is not specified, the locale is inherited from the environment that initdb runs in. Locale support is described in Section 21.1.

--lc-collate=locale
--lc-ctype=locale
--lc-messages=locale
--lc-monetary=locale
--lc-numeric=locale
--lc-time=locale

Like --locale, but only sets the locale in the specified category.

--no-locale

Equivalent to --locale=C.

-N
--no-sync

By default, initdb will wait for all files to be written safely to disk. This option causes initdb to return without waiting, which is faster, but means that a subsequent operating system crash can leave the data directory corrupt. Generally, this option is useful for testing, but should not be used when creating a production installation.

--pwfile=filename

Makes initdb read the database superuser's password from a file. The first line of the file is taken as the password.

-S
--sync-only

Safely write all database files to disk and exit. This does not perform any of the normal initdb operations.

-T config
--text-search-config=config

Sets the default text search configuration. See default_text_search_config for further information.

-U username
--username=username

Selects the user name of the database superuser. This defaults to the name of the effective user running initdb. It is really not important what the superuser's name is, but one might choose to keep the customary name lightdb, even if the operating system user's name is different.

-W
--pwprompt

Makes initdb prompt for a password to give the database superuser. If you don't plan on using password authentication, this is not important. Otherwise you won't be able to use password authentication until you have a password set up.

-X directory
--waldir=directory

This option specifies the directory where the write-ahead log should be stored.

--wal-segsize=size

Set the WAL segment size, in megabytes. This is the size of each individual file in the WAL log. The default size is 512 megabytes. The value must be a power of 2 between 1 and 1024 (megabytes). This option can only be set during initialization, and cannot be changed later.

It may be useful to adjust this size to control the granularity of WAL log shipping or archiving. Also, in databases with a high volume of WAL, the sheer number of WAL files per directory can become a performance and management problem. Increasing the WAL file size will reduce the number of WAL files.

--install-mode=mode

Database cluster installation mode, there are three installation modes.

  • single: stand-alone version.

  • ha: high availability version.

  • distributed: distributed version.

The default installation mode is single.

--compatible-type=type

Database cluster compatibility type, there are three compatibility types:

  • off: not compatible with other database features.

  • mysql: compatible with MySQL database features.

  • oracle: compatible with Oracle database features.

The default compatibility type is off.

Other, less commonly used, options are also available:

-d
--debug

Print debugging output from the bootstrap backend and a few other messages of lesser interest for the general public. The bootstrap backend is the program initdb uses to create the catalog tables. This option generates a tremendous amount of extremely boring output.

-L directory

Specifies where initdb should find its input files to initialize the database cluster. This is normally not necessary. You will be told if you need to specify their location explicitly.

-n
--no-clean

By default, when initdb determines that an error prevented it from completely creating the database cluster, it removes any files it might have created before discovering that it cannot finish the job. This option inhibits tidying-up and is thus useful for debugging.

Other options:

-V
--version

Print the initdb version and exit.

-?
--help

Show help about initdb command line arguments, and exit.

Environment

LTDATA

Specifies the directory where the database cluster is to be stored; can be overridden using the -D option.

LT_COLOR

Specifies whether to use color in diagnostic messages. Possible values are always, auto and never.

TZ

Specifies the default time zone of the created database cluster. The value should be a full time zone name (see Section 8.5.3).

This utility, like most other LightDB utilities, also uses the environment variables supported by libpq (see Section 32.14).

Notes

It is recommended to use lt_initdb, otherwise some functions are unavailable.

If you are run initdb directly, you can using like:

          $LTHOME/scripts/5_lightdb_modify_para.sh $LTHOME $LTDATA OLTP/OLAP shared_buffers(MB) effective_cache_size(MB) $LTPORT $INSTALL_MODE $COMPATIBLE_TYPE
          $LTHOME/scripts/6_lightdb_start.sh $LTHOME $LTDATA (if not started)
          $LTHOME/scripts/8_lightdb_create_extension.sh $LTHOME $LTPORT $INSTALL_MODE