CREATE EXTERNAL TABLE

Creates an external table. External tables serve as connectors to your external data sources. External tables store no source data within Firebolt — only metadata that specifies the location of external data files and parameters for how they should be processed. For more information, see Working with external tables.

Syntax

CREATE EXTERNAL TABLE [ IF NOT EXISTS ] <table> (
    <column_name> <column_type> [ PARTITION('<regex>') ]
    [ , <column_name2> <column_type2> [ PARTITION('<regex>') ] ]
    [ ,...<column_name3> <column_type3> [ PARTITION('<regex>') ] ]
)
-- Data source (choose one):
{
    LOCATION = <location_name>                            -- (recommended)
    |
    URL = 's3://<bucket_name>[/<folder>][/...]/'
}

-- Required parameters:
OBJECT_PATTERN = '<object_pattern>'
TYPE = ( <type> ) [ <type_option> ]

-- Optional parameters:
[ CREDENTIALS = {
    ( AWS_ACCESS_KEY_ID = '<aws_access_key_id>'
      AWS_SECRET_ACCESS_KEY = '<aws_secret_access_key>'
      [ AWS_SESSION_TOKEN = '<aws_session_token>' ] )
    |
    ( AWS_ROLE_ARN = '<aws_role_arn>'
      [ AWS_ROLE_EXTERNAL_ID = '<aws_role_external_id>' ] )
} ]
[ COMPRESSION = <compression_type> ]
[ CROSS_REGION_REQUEST_MODE = <mode> ]
[ DESCRIPTION = '<description>' ]
[ REPLACE_NON_UTF8_BYTES => { TRUE | FALSE }]

Parameters

Parameter	Description
`<table>`	An identifier that specifies the name of the external table. This name should be unique within the database. For identifier usage and syntax, see Object identifiers.
`<column_name>`	An identifier that specifies the name of the column. This name should be unique within the table. Note: If column names are using mixed case, wrap your column name definitions in double quotes (`"`); otherwise they will be translated to lower case and will not match the mixed case Parquet schema.
`<column_type>`	Specifies the data type for the column.
`PARTITION`	An optional keyword. When specified, allows you to use a regular expression `<regex>` to extract a value from the file prefix to be stored as the column value. For more information, see PARTITION.
`LOCATION`	The name of a location object that contains the Amazon S3 URL and credentials. This is the recommended approach for specifying the source. See (CREATE LOCATION) for details. The location must exist and you must have appropriate permissions to use it.
`CREDENTIALS`	Specifies the AWS credentials with permission to access the Amazon S3 location specified using `URL`. For more information, see CREDENTIALS.
`URL`	The path to an Amazon S3 URL where the source files are located. For example, `s3://my_bucket/my_folder/`.
`OBJECT_PATTERN`	Specifies the file naming pattern that Firebolt ingests when using this table. For more information, see OBJECT_PATTERN.
`TYPE`	Specifies the file type Firebolt expects to ingest given the `OBJECT_PATTERN`. If a file referenced using `OBJECT_PATTERN` does not conform to the specified `TYPE`, an error occurs. For more information, see TYPE.
`<type_option>`	Allows configuration for ingesting different CSV file formats. Type option can be set at this top level, or as an option in the `TYPE` parameter.
`COMPRESSION`	See COMPRESSION.
`CROSS_REGION_REQUEST_MODE`	Allows reading data from a bucket in a different Amazon S3 region than where your engine is running. For more information, see CROSS_REGION_REQUEST_MODE.
`DESCRIPTION`	The optional description of the table.
`REPLACE_NON_UTF8_BYTES`	Whether to replace non-UTF8 bytes in string columns with the Unicode replacement character. Since Firebolt’s TEXT data type requires all values to be valid UTF8, non-UTF8 bytes in string columns in the external table are replaced with the Unicode replacement character (�, U+FFFD) when using this option. Otherwise, an error is raised. Currently only supported for the Parquet format. Default: false.

Using location objects

Firebolt recommends using location objects as a secure, centralized way to manage Amazon S3 credentials and URLs. Use location objects for:

Centralized credential management.
Eliminating the exposure of credentials in queries.
Enabling role-based access control.
Simplified maintenance and updates.

For a comprehensive guide to LOCATION objects, see LOCATION objects. Example The following code example creates my_external_table in that loads data from Parquet files matching the *.parquet pattern in my_data_location:

CREATE EXTERNAL TABLE my_external_table
(
    c_id INTEGER,
    c_name TEXT
)
LOCATION = my_data_location
OBJECT_PATTERN = '*.parquet'
TYPE = (PARQUET);

For detailed information, see CREATE LOCATION.

Common `LOCATION` errors

Providing the location name as a string literal instead of an identifier results in an error, as shown in the following code example:

CREATE EXTERNAL TABLE et_1 (x INT NOT NULL, y TEXT NOT NULL)
LOCATION = 'location_1'  -- Error: Parameter LOCATION must be of type IDENTIFIER
OBJECT_PATTERN = 'simple.csv'
TYPE = CSV;

If the specified location doesn’t exist or you lack permission to use it, an error occurs, as shown in the following code example:

CREATE EXTERNAL TABLE et_2 (x INT NOT NULL, y TEXT NOT NULL)
LOCATION = nonexistent_location  -- Error: location 'nonexistent_location' does not exist or not authorized
OBJECT_PATTERN = 'simple.csv'
TYPE = CSV;

PARTITION

In some applications, such as Hive partitioning, files use a folder naming convention to identify which partition their data belongs to. The PARTITION keyword allows you to specify a regular expression, <regex>, to extract a portion of the file path and store it in the specified column when Firebolt uses the external table to ingest partitioned data. Using PARTITION in this way is one method of extracting partition data from file paths. Another method is to use the table metadata column, $source_file_name, during the INSERT operation.

Guidelines for creating the regex

The regular expression is matched against the object prefix, not including the s3://<bucket_name>/ portion of the prefix.
You can specify as many PARTITION columns as you need, each extracting a different portion of the object prefix.
For each PARTITION column, you must specify a re2 regular expression that contains a capturing group, which determines the column value.
When <column_type> is DATE, Firebolt requires up to three capturing groups that must be in the order of year, month, and day.
When <column_type> is TIMESTAMP, Firebolt requires up to six capturing groups that must be in the order of year, month, day, hour, minute, second.
Firebolt tries to convert the captured string to the specified <column_type>. If the type conversion fails, the ingest will error out.

In most cases, the easiest way to build a regular expression is as follows:

Count the number of folders in the path, not including the bucket name.
Concatenate the string [^/]+/ according to the number of folders.
Prefix the regex with an additional [^/]+ for the file name.
Wrap the [^/]+ in the right folder with a capturing group parenthesis, such as ([^/]+).

For more information, see Match groups on the RegexOne website. To test your regular expressions, online tools such as regex101 are available.

Example–extract Hive-compatible partitions

The example below demonstrates a CREATE EXTERNAL TABLE statement that creates the table my_ext_table. This table is used to ingest all files with a *.parquet file extension in any sub-folder of the Amazon S3 bucket s3://my_bucket. Consider an example where folders and files in the bucket have the following consistent pattern, which is common for Hive partitions:

s3://my_bucket/c_type=xyz/year=2018/month=01/part-00001.parquet
s3://my_bucket/c_type=xyz/year=2018/month=01/part-00002.parquet
s3://my_bucket/c_type=abc/year=2018/month=01/part-00001.parquet
s3://my_bucket/c_type=abc/year=2018/month=01/part-00002.parquet
[...]

In the example CREATE EXTERNAL TABLE statement below, the PARTITION keyword in the column definition for c_type specifies a regular expression. This expression extracts the portion of the Amazon S3 path name that correspond to the xyz or abc within c_type=xyz or c_type=abc.

CREATE EXTERNAL TABLE my_ext_table (
  c_id    INTEGER,
  c_name  TEXT,
  c_type  TEXT PARTITION('[^/]+/c_type=([^/]+)/[^/]+/[^/]+')
)
CREDENTIALS = (AWS_ACCESS_KEY_ID = 'AKIAIOSFODNN7EXAMPLE' AWS_SECRET_ACCESS_KEY = 'wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY')
URL = 's3://my_bucket/'
OBJECT_PATTERN= '*.parquet'
TYPE = (PARQUET)

When Firebolt ingests the data from a Parquet file stored in that path, the c_type column for each row contains the extracted portion of the path. For the files listed above, the extraction results in the following values. c_id and c_name are values stored within the respective Parquet files, while c_type are values extracted from the file path.

`c_id`	`c_name`	`c_type`
1ef4302294	Njimba	xyz
8b98470659	Yuang	xyz
98734hkk89	Cole	xyz
38cjodjlo8	Blanda	xyz
448dfgkl12	Harris	abc
j987rr3233	Espinoza	abc

CREDENTIALS

Unless reading from a public bucket, credentials are required to access your data on AWS Amazon S3. Both access key and IAM role based permissions are supported.

Syntax for Access Key & Secret

CREDENTIALS = (AWS_ACCESS_KEY_ID = '<aws_access_key_id>' AWS_SECRET_ACCESS_KEY = '<aws_secret_access_key>' [ AWS_SESSION_TOKEN = '<aws_session_token>' ] )

Parameters

Parameters	Description	Data type
`AWS_ACCESS_KEY_ID`	The AWS access key ID.	`TEXT`
`AWS_SECRET_ACCESS_KEY`	The AWS secret access key.	`TEXT`
`AWS_SESSION_TOKEN`	The optional AWS session token, used by temporary credentials.	`TEXT`

Syntax for IAM role

CREDENTIALS = ( AWS_ROLE_ARN = '<aws_role_arn>' [ AWS_ROLE_EXTERNAL_ID = '<aws_role_external_id>' ] )

Parameters

Parameters	Description	Data type
`AWS_ROLE_ARN`	The AWS role ARN (Amazon Resource Name).	`TEXT`
`AWS_ROLE_EXTERNAL_ID`	The AWS role external id.	`TEXT`

The following example authenticates with a role and includes a recommended external ID:

CREATE EXTERNAL TABLE my_external_table
(
    c_id INTEGER,
    c_name TEXT
)
CREDENTIALS = ( AWS_ROLE_ARN = 'arn:aws:iam::123456789012:role/my-firebolt-role' AWS_ROLE_EXTERNAL_ID = 'my-external-id' )
URL = 's3://my_bucket/'
OBJECT_PATTERN = '*.parquet'
TYPE = (PARQUET)

For role-based AWS access you can additionally set an external ID. An external ID is a value you choose and control that AWS checks when Firebolt assumes your role, adding a second condition on top of your account’s unique IAM principal. Configuring one is a recommended best practice. See IAM roles.

In case you don’t have the access key and secret to access your Amazon S3 bucket, read more here on how to obtain them. Or learn how to create an IAM Role on your bucket to enable access from Firebolt here.

OBJECT_PATTERN

An external table enables reading some (or all) files from an Amazon S3 bucket that you have read access to. The Amazon S3 bucket that you reference must be in the same AWS Region as the Firebolt database. TheOBJECT_PATTERN parameter identifies which files represent the data for the external table.OBJECT_PATTERN is a glob that selects files within the URL or LOCATION.

Syntax

OBJECT_PATTERN = '<object_pattern>'

Parameters

Parameters	Description	Data type
`OBJECT_PATTERN`	Specify the data pattern to be found in your data source. For example, *.parquet indicates that all Parquet files should be found.	`TEXT`

The following wildcards are supported:

'*' matches any sequence of characters
'?' matches any single character
[SET] matches any single character in the specified set
[!SET] matches any character, not in the specified set.

Example

In the following layout of objects in a bucket, the data is partitioned according to client type, year, and month, with multiple Parquet files in each partition. The examples demonstrate how choosing both URL and OBJECT_PATTERN impacts the objects that are retrieved from Amazon S3.

s3://bucket/c_type=xyz/year=2018/month=01/part-00001.parquet
s3://bucket/c_type=xyz/year=2018/month=01/part-00002.parquet
...
s3://bucket/c_type=xyz/year=2018/month=12/part-00001.parquet
s3://bucket/c_type=xyz/year=2018/month=12/part-00002.parquet
...
s3://bucket/c_type=xyz/year=2019/month=01/part-00001.parquet
s3://bucket/c_type=xyz/year=2019/month=01/part-00002.parquet
...
s3://bucket/c_type=xyz/year=2020/month=01/part-00001.parquet
s3://bucket/c_type=xyz/year=2020/month=01/part-00002.parquet
...
s3://bucket/c_type=abc/year=2018/month=01/part-00001.parquet
s3://bucket/c_type=abc/year=2018/month=01/part-00002.parquet
...

Following are some common use cases for URL and object pattern combinations:

Use cases	Syntax
Get all files for file type xyz	`URL = 's3://bucket/c_type=xyz/'` `OBJECT_PATTERN = '\'` `URL = 's3://bucket/'<br/>OBJECT_PATTERN = 'c_type=xyz/\'`
Get one specific file: `c_type=xyz/year=2018/month=01/part-00001.parquet`	`URL = 's3://bucket/c_type=xyz/year=2018/month=01/'` `OBJECT_PATTERN = 'part-00001.parquet'`
Get all parquet files for type xyz	`URL = 's3://bucket/c_type=xyz/'` `OBJECT_PATTERN = '\.parquet'`

TYPE

Specifies the type of the files in Amazon S3. The following types and type options are supported.

CSV Types

TYPE = (CSV [ <type_option> ])

TYPE = (CSV)
[ <type_option> ]

The following type options allow configuration for ingesting different CSV file formats.

[ALLOW_DOUBLE_QUOTES = {TRUE|FALSE}] [ALLOW_SINGLE_QUOTES = {TRUE|FALSE}] With ALLOW_DOUBLE_QUOTES = TRUE or ALLOW_SINGLE_QUOTES = TRUE you define that unescaped double or single quotes in CSV input file will not cause an error to be generated on ingest. By default ALLOW_DOUBLE_QUOTES and ALLOW_SINGLE_QUOTES are set to TRUE.
[ALLOW_COLUMN_MISMATCH = {TRUE|FALSE}] With ALLOW_COLUMN_MISMATCH = TRUE the number of delimited columns in a CSV input file can be fewer than the number of columns in the corresponding table. By default, ALLOW_COLUMN_MISMATCH is set to FALSE, and an error is generated if the number of columns is fewer than the number of columns defined in the external table. If set to TRUE, and an input file record contains fewer columns than defined in the external table, the non-matching columns in the table are loaded with NULL values.
[ALLOW_UNKNOWN_FIELDS = {TRUE|FALSE}] With ALLOW_UNKNOWN_FIELDS = TRUE the number of delimited columns in a CSV input file can be more than the number of columns in the corresponding table. By default, ALLOW_UNKNOWN_FIELDS is set to FALSE, and an error is generated if the number of columns is more than the number of columns defined in the external table. If set to TRUE, and an input file record contains more columns than defined in the external table, the non-matching columns in the table are ignored.
[ESCAPE_CHARACTER = {‘<character>’|NONE} With ESCAPE_CHARACTER = '<character>' you can define which character is used to escape, to change interpretations from the original. By default, the ESCAPE_CHARACTER value is set to \. If, for example, you want to use " as a value and not as delimiter for string, you can escape like \", with the default escape character.
[FIELD_DELIMITER = '<field_delimeter>'] With FIELD_DELIMITER = '<field_delimeter>', you can define a custom field delimiter to separate fields for ingest. By default, the FIELD_DELIMITER is set as ,.
[NEW_LINE_CHARACTER = '<new_line_character>'] With NEW_LINE_CHARACTER = '<new_line_character>', you can define a custom new line delimiter to separate entries for ingest. By default, the NEW_LINE_CHARACTER is set as the end of line character \n, but also supports other end of line conventions, such as \r\n, \n\r, and \r, as well as multi-character delimiters, such as #*~.
[NULL_STRING = '<null_string>'] With NULL_STRING = '<null_string>' you can define which set of characters is interpreted as NULL. By default, the NULL_STRING value is set to \\N.
[SKIP_BLANK_LINES {TRUE|FALSE}] With SKIP_BLANK_LINES = TRUE any blank lines encountered in the CSV input file will be skipped. By default, SKIP_BLANK_LINES is set to FALSE, and an error is generated if blank lines are encountered on ingest.
[SKIP_HEADER_ROWS = {TRUE|FALSE}] With SKIP_HEADER_ROWS = TRUE, Firebolt assumes that the first row in each file read from Amazon S3 is a header row and skips it when ingesting data. When set to FALSE, which is the default if not specified, Firebolt ingests the first row as data.

JSON Types

TYPE = (JSON [PARSE_AS_JSON = {TRUE|FALSE}] [PARSE_AS_TEXT = {TRUE|FALSE}])

Firebolt reads newline-delimited JSON, single documents (including pretty-printed, multi-line ones), and top-level JSON arrays of the form [ {...}, {...} ]. Files may be compressed (see COMPRESSION). TYPE = (JSON) supports three column mappings. PARSE_AS_JSON and PARSE_AS_TEXT are mutually exclusive and both default to FALSE:

PARSE_AS_JSON = TRUE ingests each document whole into a single JSON-typed column, which you query with JSON functions. The table must declare exactly one data column (partition columns excepted), of type JSON, and each document is validated as well-formed JSON on read. This is the external-table equivalent of READ_JSON(..., PARSE_AS_JSON => TRUE).
PARSE_AS_TEXT = TRUE ingests each document whole into a single TEXT column, leaving field extraction to query time. The table must declare exactly one data column (partition columns excepted), of type TEXT or JSON.
With both FALSE (the default), Firebolt maps each key in a JSON object to the table column of the same name and inserts the key’s value into that column. Keys with no matching column are ignored; columns with no matching key take their default.

Other Types

TYPE = (ORC)
TYPE = (PARQUET)
TYPE = (AVRO)
TYPE = (TSV)

All type options for CSV above, except for FIELD_DELIMITER, are also supported for the TSV file type.

Example

Creating an external table that reads Parquet files from Amazon S3 is being done with the following statement:

CREATE EXTERNAL TABLE my_external_table
(
    c_id INTEGER,
    c_name TEXT
)
CREDENTIALS = (AWS_ACCESS_KEY_ID = '****' AWS_SECRET_ACCESS_KEY = '****')
URL = 's3://bucket/'
OBJECT_PATTERN= '*.parquet'
TYPE = (PARQUET)

COMPRESSION

Specifies the compression type of the files matching the specified OBJECT_PATTERN in Amazon S3.

Syntax

[COMPRESSION = <compression_type>]

Parameters

Parameters	Description
`<compression_type>`	Specifies the compression type of files. `GZIP` is supported.

Example

The example below creates an external table to ingest CSV files from Amazon S3 that are compressed using gzip. The credentials for an IAM user with access to the bucket are provided.

CREATE EXTERNAL TABLE my_external_table
(
    c_id INTEGER,
    c_name TEXT
)
CREDENTIALS = (AWS_ACCESS_KEY_ID = 'AKIAIOSFODNN7EXAMPLE' AWS_SECRET_ACCESS_KEY = 'wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY')
URL = 's3://mybucket/'
OBJECT_PATTERN= '*.csv.gz'
TYPE = (CSV)
COMPRESSION = GZIP

CROSS_REGION_REQUEST_MODE

Use this parameter to read data from an Amazon S3 region different than where your engine is running. Unlike query-level settings, this parameter is specified only during external table creation and is automatically persisted for all subsequent SELECT queries on that table. Note that query-level settings cannot be applied to CREATE TABLE operations, as these settings are not enabled for table creation. The table-level parameter is required for file validation during table creation. If the system setting is specified during SELECT queries, the table-level parameter will override it, so it will have no effect. It has three modes: disabled, auto, and enforced, where disabled is the default mode. For detailed explanations of each mode, see the cross-region data access documentation.

Example

The example below creates an external table with cross-region access enabled:

CREATE EXTERNAL TABLE e_playstats(
  "GameID" BIGINT NULL,
  "PlayerID" BIGINT NULL
)
URL = 's3://firebolt-publishing-public/help_center_assets/firebolt_sample_dataset/playstats/'
OBJECT_PATTERN = '*.parquet'
TYPE = (PARQUET)
CROSS_REGION_REQUEST_MODE = 'auto';

SELECT * FROM e_playstats LIMIT 5;

Overview

Performance and Observability

Security

Self-Managed

Managed service

Guides

SQL reference

Release notes

API reference

Legal

Syntax

Parameters

Using location objects

Common `LOCATION` errors

PARTITION

Guidelines for creating the regex

Example–extract Hive-compatible partitions

CREDENTIALS

Syntax for Access Key & Secret

Parameters

Syntax for IAM role

Parameters

OBJECT_PATTERN

Syntax

Parameters

Example

TYPE

CSV Types

JSON Types

Other Types

Example

COMPRESSION

Syntax

Parameters

Example

CROSS_REGION_REQUEST_MODE

Example

​Syntax

​Parameters

​Using location objects

​Common LOCATION errors

​PARTITION

​Guidelines for creating the regex

​Example–extract Hive-compatible partitions

​CREDENTIALS

​Syntax for Access Key & Secret

​Parameters

​Syntax for IAM role

​Parameters

​OBJECT_PATTERN

​Syntax

​Parameters

​Example

​TYPE

​CSV Types

​JSON Types

​Other Types

​Example

​COMPRESSION

​Syntax

​Parameters

​Example

​CROSS_REGION_REQUEST_MODE

​Example

Syntax

Parameters

Using location objects

Common `LOCATION` errors

PARTITION

Guidelines for creating the regex

Example–extract Hive-compatible partitions

CREDENTIALS

Syntax for Access Key & Secret

Parameters

Syntax for IAM role

Parameters

OBJECT_PATTERN

Syntax

Parameters

Example

TYPE

CSV Types

JSON Types

Other Types

Example

COMPRESSION

Syntax

Parameters

Example

CROSS_REGION_REQUEST_MODE

Example