The IMPORT statement imports the following types of data into CockroachDB:

Tip:

This page has reference information about the IMPORT statement. For instructions and working examples showing how to migrate data from other databases and formats, see the Migration Overview.

Warning:

IMPORT only works for creating new tables. It does not support adding data to existing tables. Also, IMPORT cannot be used within a transaction.

Required privileges

Only members of the admin role can run IMPORT. By default, the root user belongs to the admin role.

Synopsis

Import a table from CSV

IMPORT TABLE table_name CREATE USING file_location ( table_elem_list ) CSV DATA ( file_location , ) WITH kv_option_list

Import a database or table from dump file

IMPORT TABLE table_name FROM import_format file_location WITH kv_option_list

Parameters

For import from CSV

Parameter Description
table_name The name of the table you want to import/create.
table_elem_list The table schema you want to use.
CREATE USING file_location If not specifying the table schema inline via table_elem_list, this is the URL of a CSV file containing the table schema.
file_location The URL of a CSV file containing the table data. This can be a comma-separated list of URLs to CSV files. For an example, see Import a table from multiple CSV files below.
WITH kv_option_list Control your import's behavior with these options.

For import from dump file

Parameter Description
table_name The name of the table you want to import/create. Use this when the dump file contains a specific table. Leave out TABLE table_name FROM when the dump file contains an entire database.
import_format PGDUMP or MYSQLDUMP
file_location The URL of a dump file you want to import.
WITH kv_option_list Control your import's behavior with these options.

Import file URLs

URLs for the files you want to import must use the format shown below. For examples, see Example file URLs.

[scheme]://[host]/[path]?[parameters]
Location Scheme Host Parameters
Amazon S3 s3 Bucket name AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_SESSION_TOKEN
Azure azure N/A (see Example file URLs AZURE_ACCOUNT_KEY, AZURE_ACCOUNT_NAME
Google Cloud 1 gs Bucket name AUTH (optional): can be default or implicit
HTTP 2 http Remote host N/A
NFS/Local 3 nodelocal N/A (see Example file URLs N/A
S3-compatible services 4 s3 Bucket name AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_SESSION_TOKEN, AWS_REGION 5 (optional), AWS_ENDPOINT
Note:

The location parameters often contain special characters that need to be URI-encoded. Use Javascript's encodeURIComponent function or Go language's url.QueryEscape function to URI-encode the parameters. Other languages provide similar functions to URI-encode special characters.

  • 1 If the AUTH parameter is implicit, all GCS connections use Google's default authentication strategy. If the AUTH parameter is default, the cloudstorage.gs.default.key cluster setting must be set to the contents of a service account file which will be used during authentication. If the AUTH parameter is not specified, the cloudstorage.gs.default.key setting will be used if it is non-empty, otherwise the implicit behavior is used.

  • 2 You can create your own HTTP server with Caddy or nginx. A custom root CA can be appended to the system's default CAs by setting the cloudstorage.http.custom_ca cluster setting, which will be used when verifying certificates from HTTPS URLs.

  • 3 The file system backup location on the NFS drive is relative to the path specified by the --external-io-dir flag set while starting the node. If the flag is set to disabled, then imports from local directories and NFS drives are disabled.

  • 4 A custom root CA can be appended to the system's default CAs by setting the cloudstorage.http.custom_ca cluster setting, which will be used when verifying certificates from an S3-compatible service.

  • 5 The AWS_REGION parameter is optional since it is not a required parameter for most S3-compatible services. Specify the parameter only if your S3-compatible service requires it.

Example file URLs

Location Example
Amazon S3 s3://acme-co/employees.sql?AWS_ACCESS_KEY_ID=123&AWS_SECRET_ACCESS_KEY=456
Azure azure://employees.sql?AZURE_ACCOUNT_KEY=123&AZURE_ACCOUNT_NAME=acme-co
Google Cloud gs://acme-co/employees.sql
HTTP http://localhost:8080/employees.sql
NFS/Local nodelocal:///employees.sql

Import options

You can control the IMPORT process's behavior using any of the following key-value pairs as a kv_option.

Key Context Value Required? Example
delimiter CSV The unicode character that delimits columns in your rows. Default: ,. No To use tab-delimited values: IMPORT TABLE foo (..) CSV DATA ('file.csv') WITH delimiter = e'\t'
comment CSV The unicode character that identifies rows to skip. No IMPORT TABLE foo (..) CSV DATA ('file.csv') WITH comment = '#'
nullif CSV The string that should be converted to NULL. No To use empty columns as NULL: IMPORT TABLE foo (..) CSV DATA ('file.csv') WITH nullif = ''
skip CSV The number of rows to be skipped while importing a file. Default: '0'. No To import CSV files with column headers: IMPORT ... CSV DATA ('file.csv') WITH skip = '1'
decompress General The decompression codec to be used: gzip, bzip, auto, or none. Default: 'auto', which guesses based on file extension (.gz, .bz, .bz2). none disables decompression. No IMPORT ... WITH decompress = 'bzip'
skip_foreign_keys Postgres, MySQL Ignore foreign key constraints in the dump file's DDL. Off by default. May be necessary to import a table with unsatisfied foreign key constraints from a full database dump. No IMPORT TABLE foo FROM MYSQLDUMP 'dump.sql' WITH skip_foreign_keys
max_row_size Postgres Override limit on line size. Default: 0.5MB. This setting may need to be tweaked if your Postgres dump file has extremely long lines, for example as part of a COPY statement. No IMPORT PGDUMP DATA ... WITH max_row_size = '5MB'

For examples showing how to use these options, see the Examples section below.

For instructions and working examples showing how to migrate data from other databases and formats, see the Migration Overview.

Requirements

Prerequisites

Before using IMPORT, you should have:

  • The schema of the table you want to import.
  • The data you want to import, preferably hosted on cloud storage. This location must be equally accessible to all nodes using the same import file location. This is necessary because the IMPORT statement is issued once by the client, but is executed concurrently across all nodes of the cluster. For more information, see the Import file location section below.

Import targets

Imported tables must not exist and must be created in the IMPORT statement. If the table you want to import already exists, you must drop it with DROP TABLE.

You can specify the target database in the table name in the IMPORT statement. If it's not specified there, the active database in the SQL session is used.

Create table

Your IMPORT statement must reference a CREATE TABLE statement representing the schema of the data you want to import. You have several options:

We also recommend specifying all secondary indexes you want to use in the CREATE TABLE statement. It is possible to add secondary indexes later, but it is significantly faster to specify them during import.

Skip foreign keys

By default, the Postgres and MySQL import formats support foreign keys. Add the skip_foreign_keys option to speed up data import by ignoring foreign key constraints in the dump file's DDL. It will also enable you to import individual tables that would otherwise fail due to dependencies on other tables.

Note:

The most common dependency issues are caused by unsatisfied foreign key relationships. You can avoid these issues by adding the skip_foreign_keys option to your IMPORT statement as needed. For more information, see the list of import options.

For example, if you get the error message pq: there is no unique constraint matching given keys for referenced table tablename, use IMPORT ... WITH skip_foreign_keys.

Available storage

Each node in the cluster is assigned an equal part of the imported data, and so must have enough temp space to store it. In addition, data is persisted as a normal table, and so there must also be enough space to hold the final, replicated data. The node's first-listed/default store directory must have enough available storage to hold its portion of the data.

On cockroach start, if you set --max-disk-temp-storage, it must also be greater than the portion of the data a node will store in temp space.

Import file location

We strongly recommend using cloud/remote storage (Amazon S3, Google Cloud Platform, etc.) for the data you want to import.

Local files are supported; however, they must be accessible to all nodes in the cluster using identical Import file URLs.

To import a local file, you have the following options:

  • Option 1. Run a local file server to make the file accessible from all nodes.

  • Option 2. Make the file accessible from each local node's store:

    1. Create an extern directory on each node's store. The pathname will differ depending on the --store flag passed to cockroach start (if any), but will look something like /path/to/cockroach-data/extern/.
    2. Copy the file to each node's extern directory.
    3. Assuming the file is called data.sql, you can access it in your IMPORT statement using the following import file URL: 'nodelocal:///data.sql'.

Table users and privileges

Imported tables are treated as new tables, so you must GRANT privileges to them.

Performance

All nodes are used during the import job, which means all nodes' CPU and RAM will be partially consumed by the IMPORT task in addition to serving normal traffic.

Viewing and controlling import jobs

After CockroachDB successfully initiates an import, it registers the import as a job, which you can view with SHOW JOBS.

After the import has been initiated, you can control it with PAUSE JOB, RESUME JOB, and CANCEL JOB.

Warning:
Pausing and then resuming an IMPORT job will cause it to restart from the beginning.

Examples

Import a table from a CSV file

To manually specify the table schema:

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> IMPORT TABLE customers (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        name TEXT,
        INDEX name_idx (name)
)
CSV DATA ('azure://acme-co/customer-import-data.csv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co')
;

To use a file to specify the table schema:

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> IMPORT TABLE customers
CREATE USING 'azure://acme-co/customer-create-table.sql?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co'
CSV DATA ('azure://acme-co/customer-import-data.csv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co')
;

Import a table from multiple CSV files

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> IMPORT TABLE customers (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        name TEXT,
        INDEX name_idx (name)
)
CSV DATA (
    'azure://acme-co/customer-import-data1.1.csv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co',
    'azure://acme-co/customer-import-data1.2.csv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co',
    'azure://acme-co/customer-import-data1.3.csv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co',
    'azure://acme-co/customer-import-data1.4.csv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co',
    'azure://acme-co/customer-import-data1.5.csv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co',    
);

Import a table from a TSV file

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> IMPORT TABLE customers (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        name TEXT,
        INDEX name_idx (name)
)
CSV DATA ('azure://acme-co/customer-import-data.tsv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co')
WITH
    delimiter = e'\t'
;

Skip commented lines

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> IMPORT TABLE customers (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        name TEXT,
        INDEX name_idx (name)
)
CSV DATA ('azure://acme-co/customer-import-data.csv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co')
WITH
    comment = '#'
;

Skip first n lines

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> IMPORT TABLE customers (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        name TEXT,
        INDEX name_idx (name)
)
CSV DATA ('azure://acme-co/customer-import-data.csv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co')
WITH
    skip = '2'
;

Use blank characters as NULL

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> IMPORT TABLE customers (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        name TEXT,
        INDEX name_idx (name)
)
CSV DATA ('azure://acme-co/customer-import-data.csv?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co')
WITH
    nullif = ''
;

Import a compressed CSV file

CockroachDB chooses the decompression codec based on the filename (the common extensions .gz or .bz2 and .bz) and uses the codec to decompress the file during import.

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> IMPORT TABLE customers (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        name TEXT,
        INDEX name_idx (name)
)
CSV DATA ('azure://acme-co/customer-import-data.csv.gz?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co')
;

Optionally, you can use the decompress option to specify the codec to be used for decompressing the file during import:

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> IMPORT TABLE customers (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        name TEXT,
        INDEX name_idx (name)
)
CSV DATA ('azure://acme-co/customer-import-data.csv.gz.latest?AZURE_ACCOUNT_KEY=hash&AZURE_ACCOUNT_NAME=acme-co')
WITH
    decompress = 'gzip'
;

Import a Postgres database dump

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> IMPORT PGDUMP 's3://your-external-storage/employees-full.sql?AWS_ACCESS_KEY_ID=123&AWS_SECRET_ACCESS_KEY=456';

For the command above to succeed, you need to have created the dump file with specific flags to pg_dump. For more information, see Migrate from Postgres.

Import a table from a Postgres database dump

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> IMPORT TABLE employees FROM PGDUMP 's3://your-external-storage/employees-full.sql?AWS_ACCESS_KEY_ID=123&AWS_SECRET_ACCESS_KEY=456' WITH skip_foreign_keys;

If the table schema specifies foreign keys into tables that do not exist yet, the WITH skip_foreign_keys shown may be needed. For more information, see the list of import options.

For the command above to succeed, you need to have created the dump file with specific flags to pg_dump. For more information, see Migrate from Postgres.

Import a CockroachDB dump file

Cockroach dump files can be imported using the IMPORT PGDUMP.

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> IMPORT PGDUMP 's3://your-external-storage/employees-full.sql?AWS_ACCESS_KEY_ID=123&AWS_SECRET_ACCESS_KEY=456';

For more information, see SQL Dump (Export).

Import a MySQL database dump

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> IMPORT MYSQLDUMP 's3://your-external-storage/employees-full.sql?AWS_ACCESS_KEY_ID=123&AWS_SECRET_ACCESS_KEY=456';

For more detailed information about importing data from MySQL, see Migrate from MySQL.

Import a table from a MySQL database dump

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> IMPORT TABLE employees FROM MYSQLDUMP 's3://your-external-storage/employees-full.sql?AWS_ACCESS_KEY_ID=123&AWS_SECRET_ACCESS_KEY=456' WITH skip_foreign_keys

If the table schema specifies foreign keys into tables that do not exist yet, the WITH skip_foreign_keys shown may be needed. For more information, see the list of import options.

For more detailed information about importing data from MySQL, see Migrate from MySQL.

Known limitation

IMPORT can sometimes fail with a "context canceled" error, or can restart itself many times without ever finishing. If this is happening, it is likely due to a high amount of disk contention. This can be mitigated by setting the kv.bulk_io_write.max_rate cluster setting to a value below your max disk write speed. For example, to set it to 10MB/s, execute:

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> SET CLUSTER SETTING kv.bulk_io_write.max_rate = '10MB';

See also



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