Updated on 2023-10-31 GMT+08:00

Exporting a Table

You can use gs_dump to export data and all object definitions of a table-level object from GaussDB(DWS). Views, sequences, and foreign tables are special tables. You can export one or more specified tables as needed. You can specify the information to be exported as follows:

  • Export full information of a table, including its data and definition.
  • Export data of a table.
  • Export the definition of a table.

Procedure

  1. Preparing an ECS as the gsql Client Host.
  2. Download the gsql client and use an SSH transfer tool (such as WinSCP) to upload it to the Linux server where gsql is to be installed. For details, see Downloading the Client.

    The user who uploads the client must have the full control permission on the target directory on the host to which the client is uploaded.

    Alternatively, you can remotely log in to the Linux host where the gsql is to be installed in SSH mode and run the following command in the Linux command window to download the gsql client:

    wget https://obs.myhuaweicloud.com/dws/download/dws_client_8.x.x_redhat_x64.zip --no-check-certificate

  3. Run the following commands to decompress the client:

    cd <Path_for_storing_the_client>
    unzip dws_client_8.x.x_redhat_x64.zip

    Where,

    • <Path_for_storing_the_client>: Replace it with the actual path.
    • dws_client_8.1.x_redhat_x86.zip: This is the client tool package of RedHat x86. Replace it with the actual one.

  4. Run the following command to configure the GaussDB(DWS) client:

    source gsql_env.sh

    If the following information is displayed, the GaussDB(DWS) client is successfully configured:

    All things done.

  5. Use gs_dump to run the following command to export the hr.staffs and hr.employments tables.

    gs_dump -W password -U jack -f /home//backup/MPPDB_table_backup -p 8000 -h 10.10.10.100 human_resource -t hr.staffs -F d
    Table 1 Common parameters

    Parameter

    Description

    Example Value

    -U

    Username for connecting to the database. If this parameter is not configured, the username of the connected database is used.

    -U jack

    -W

    User password for database connection.

    • This parameter is not required for database administrators if the trust policy is used for authentication.
    • If you connect to the database without specifying this parameter and you are not a database administrator, you will be prompted to enter the password.

    -W password

    -f

    Folder to store exported files. If this parameter is not specified, the exported files are stored in the standard output.

    -f /home//backup/MPPDB_table_backup

    -p

    Name extension of the TCP port on which the server is listening or the local Unix domain socket. This parameter is configured to ensure connections.

    -p 8000

    -h

    Cluster address: If a public network address is used for connection, set this parameter to Public Network Address or Public Network Domain Name. If a private network address is used for connection, set this parameter to Private Network Address or Private Network Domain Name.

    -h 10.10.10.100

    dbname

    Name of the database to be exported.

    human_resource

    -t

    Table (or view, sequence, foreign table) to be exported. You can specify multiple tables by listing them or using wildcard characters. When you use wildcard characters, quote wildcard patterns with single quotation marks ('') to prevent the shell from expanding the wildcard characters.

    • Single table: Enter -t schema.table.
    • Multiple tables: Enter -t schema.table for each table.
    • Single table: -t hr.staffs
    • Multiple tables: -t hr.staffs -t hr.employments

    -F

    Format of exported files. The values of -F are as follows:

    • p: plain text
    • c: custom
    • d: directory
    • t: .tar

    -F d

    For details about other parameters, see "gs_dump" in the Tool Guide.

Examples

Example 1: Use gs_dump to run the following command to export full information of the hr.staffs table. The exported files are in text format.
gs_dump -W password -U jack -f /home//backup/MPPDB_table_backup.sql -p 8000 -h 10.10.10.100 human_resource -t hr.staffs -Z 6 -F p
gs_dump[port=''][human_resource][2017-07-21 17:05:10]: dump database human_resource successfully
gs_dump[port=''][human_resource][2017-07-21 17:05:10]: total time: 3116  ms
Example 2: Use gs_dump to run the following command to export data of the hr.staffs table. The exported files are in .tar format.
gs_dump -W password -U jack -f /home//backup/MPPDB_table_data_backup.tar -p 8000 -h 10.10.10.100 human_resource -t hr.staffs -a -F t 
gs_dump[port=''][human_resource][2017-07-21 17:04:26]: dump database human_resource successfully
gs_dump[port=''][human_resource][2017-07-21 17:04:26]: total time: 2570  ms
Example 3: Use gs_dump to run the following command to export the definition of the hr.staffs table. The exported files are stored in a directory.
gs_dump -W password -U jack -f /home//backup/MPPDB_table_def_backup -p 8000 -h 10.10.10.100 human_resource -t hr.staffs -s -F d 
gs_dump[port=''][human_resource][2017-07-21 17:03:09]: dump database human_resource successfully
gs_dump[port=''][human_resource][2017-07-21 17:03:09]: total time: 2297  ms 
Example 4: Use gs_dump to run the following command to export the human_resource database excluding the hr.staffs table. The exported files are in a custom format.
gs_dump -W password -U jack -f /home//backup/MPPDB_table_backup4.dmp -p 8000 -h 10.10.10.100 human_resource -T hr.staffs -F c
gs_dump[port=''][human_resource][2017-07-21 17:14:11]: dump database human_resource successfully
gs_dump[port=''][human_resource][2017-07-21 17:14:11]: total time: 2450  ms
Example 5: Use gs_dump to run the following command to export the hr.staffs and hr.employments tables. The exported files are in text format.
gs_dump -W password -U jack -f /home//backup/MPPDB_table_backup1.sql -p 8000 -h 10.10.10.100 human_resource -t hr.staffs -t hr.employments -F p
gs_dump[port=''][human_resource][2017-07-21 17:19:42]: dump database human_resource successfully
gs_dump[port=''][human_resource][2017-07-21 17:19:42]: total time: 2414  ms
Example 6: Use gs_dump to run the following command to export the human_resource database excluding the hr.staffs and hr.employments tables. The exported files are in text format.
gs_dump -W password -U jack -f /home//backup/MPPDB_table_backup2.sql -p 8000 -h 10.10.10.100 human_resource -T hr.staffs -T hr.employments -F p
gs_dump[port=''][human_resource][2017-07-21 17:21:02]: dump database human_resource successfully
gs_dump[port=''][human_resource][2017-07-21 17:21:02]: total time: 3165  ms

Example 7: Use gs_dump to run the following command to export data and definition of the hr.staffs table, and the definition of the hr.employments table. The exported files are in .tar format.

gs_dump -W password -U jack -f /home//backup/MPPDB_table_backup3.tar -p 8000 -h 10.10.10.100 human_resource -t hr.staffs -t hr.employments --exclude-table-data hr.employments -F t
gs_dump[port=''][human_resource][2018-11-14 11:32:02]: dump database human_resource successfully
gs_dump[port=''][human_resource][2018-11-14 11:32:02]: total time: 1645  ms

Example 8: Use gs_dump to run the following command to export data and definition of the hr.staffs table, encrypt the exported files, and store them in text format.

gs_dump -W password -U jack -f /home//backup/MPPDB_table_backup4.sql -p 8000 -h 10.10.10.100 human_resource -t hr.staffs --with-encryption AES128 --with-key 1212121212121212 -F p
gs_dump[port=''][human_resource][2018-11-14 11:35:30]: dump database human_resource successfully
gs_dump[port=''][human_resource][2018-11-14 11:35:30]: total time: 6708  ms

Example 9: Use gs_dump to run the following command to export all tables, including views, sequences, and foreign tables, in the public schema, and the staffs table in the hr schema, including data and table definition. The exported files are in a custom format.

gs_dump -W password -U jack -f /home//backup/MPPDB_table_backup5.dmp -p 8000 -h 10.10.10.100 human_resource -t public.* -t hr.staffs -F c
gs_dump[port=''][human_resource][2018-12-13 09:40:24]: dump database human_resource successfully
gs_dump[port=''][human_resource][2018-12-13 09:40:24]: total time: 896  ms

Example 10: Use gs_dump to run the following command to export the definition of the view referencing to the test1 table in the t1 schema. The exported files are in a custom format.

gs_dump -W password -U jack -f /home//backup/MPPDB_view_backup6 -p 8000 -h 10.10.10.100 human_resource -t t1.test1 --include-depend-objs --exclude-self -F d
gs_dump[port=''][jack][2018-11-14 17:21:18]: dump database human_resource successfully
gs_dump[port=''][jack][2018-11-14 17:21:23]: total time: 4239  ms