ALTER STAGE¶
Modifies the properties for an existing named internal or external stage.
- See also:
Syntax¶
ALTER STAGE [ IF EXISTS ] <name> RENAME TO <new_name>
ALTER STAGE [ IF EXISTS ] <name> SET TAG <tag_name> = '<tag_value>' [ , <tag_name> = '<tag_value>' ... ]
ALTER STAGE <name> UNSET TAG <tag_name> [ , <tag_name> ... ]
-- Internal stage
ALTER STAGE [ IF EXISTS ] <name> SET
[ FILE_FORMAT = ( { FORMAT_NAME = '<file_format_name>' | TYPE = { CSV | JSON | AVRO | ORC | PARQUET | XML | CUSTOM } [ formatTypeOptions ] } ) ]
{ [ COMMENT = '<string_literal>' ] }
-- External stage
ALTER STAGE [ IF EXISTS ] <name> SET {
[ externalStageParams ]
[ FILE_FORMAT = ( { FORMAT_NAME = '<file_format_name>' | TYPE = { CSV | JSON | AVRO | ORC | PARQUET | XML | CUSTOM } [ formatTypeOptions ] } ) ]
[ COMMENT = '<string_literal>' ]
}
Where:
externalStageParams (for Amazon S3) ::= [ URL = '<protocol>://<bucket>[/<path>/]' ] [ { STORAGE_INTEGRATION = <integration_name> } | { CREDENTIALS = ( { { AWS_KEY_ID = '<string>' AWS_SECRET_KEY = '<string>' [ AWS_TOKEN = '<string>' ] } | AWS_ROLE = '<string>' } ) } ] [ ENCRYPTION = ( [ TYPE = 'AWS_CSE' ] MASTER_KEY = '<string>' | TYPE = 'AWS_SSE_S3' | TYPE = 'AWS_SSE_KMS' [ KMS_KEY_ID = '<string>' ] | TYPE = 'NONE' ) ]externalStageParams (for Google Cloud Storage) ::= [ URL = 'gcs://<bucket>[/<path>/]' ] [ STORAGE_INTEGRATION = <integration_name> } ] [ ENCRYPTION = ( TYPE = 'GCS_SSE_KMS' [ KMS_KEY_ID = '<string>' ] | TYPE = 'NONE' ) ]externalStageParams (for Microsoft Azure) ::= [ URL = 'azure://<account>.blob.core.windows.net/<container>[/<path>/]' ] [ { STORAGE_INTEGRATION = <integration_name> } | { CREDENTIALS = ( [ AZURE_SAS_TOKEN = '<string>' ] ) } ] [ ENCRYPTION = ( TYPE = 'AZURE_CSE' [ MASTER_KEY = '<string>' ] | TYPE = 'NONE' ) ] [ USE_PRIVATELINK_ENDPOINT = { TRUE | FALSE } ]formatTypeOptions ::= -- If TYPE = CSV COMPRESSION = AUTO | GZIP | BZ2 | BROTLI | ZSTD | DEFLATE | RAW_DEFLATE | NONE RECORD_DELIMITER = '<string>' | NONE FIELD_DELIMITER = '<string>' | NONE FILE_EXTENSION = '<string>' PARSE_HEADER = TRUE | FALSE SKIP_HEADER = <integer> SKIP_BLANK_LINES = TRUE | FALSE DATE_FORMAT = '<string>' | AUTO TIME_FORMAT = '<string>' | AUTO TIMESTAMP_FORMAT = '<string>' | AUTO BINARY_FORMAT = HEX | BASE64 | UTF8 ESCAPE = '<character>' | NONE ESCAPE_UNENCLOSED_FIELD = '<character>' | NONE TRIM_SPACE = TRUE | FALSE FIELD_OPTIONALLY_ENCLOSED_BY = '<character>' | NONE NULL_IF = ( '<string>' [ , '<string>' ... ] ) ERROR_ON_COLUMN_COUNT_MISMATCH = TRUE | FALSE REPLACE_INVALID_CHARACTERS = TRUE | FALSE EMPTY_FIELD_AS_NULL = TRUE | FALSE SKIP_BYTE_ORDER_MARK = TRUE | FALSE ENCODING = '<string>' | UTF8 -- If TYPE = JSON COMPRESSION = AUTO | GZIP | BZ2 | BROTLI | ZSTD | DEFLATE | RAW_DEFLATE | NONE DATE_FORMAT = '<string>' | AUTO TIME_FORMAT = '<string>' | AUTO TIMESTAMP_FORMAT = '<string>' | AUTO BINARY_FORMAT = HEX | BASE64 | UTF8 TRIM_SPACE = TRUE | FALSE NULL_IF = ( '<string>' [ , '<string>' ... ] ) FILE_EXTENSION = '<string>' ENABLE_OCTAL = TRUE | FALSE ALLOW_DUPLICATE = TRUE | FALSE STRIP_OUTER_ARRAY = TRUE | FALSE STRIP_NULL_VALUES = TRUE | FALSE REPLACE_INVALID_CHARACTERS = TRUE | FALSE IGNORE_UTF8_ERRORS = TRUE | FALSE SKIP_BYTE_ORDER_MARK = TRUE | FALSE -- If TYPE = AVRO COMPRESSION = AUTO | GZIP | BROTLI | ZSTD | DEFLATE | RAW_DEFLATE | NONE TRIM_SPACE = TRUE | FALSE REPLACE_INVALID_CHARACTERS = TRUE | FALSE NULL_IF = ( '<string>' [ , '<string>' ... ] ) -- If TYPE = ORC TRIM_SPACE = TRUE | FALSE REPLACE_INVALID_CHARACTERS = TRUE | FALSE NULL_IF = ( '<string>' [ , '<string>' ... ] ) -- If TYPE = PARQUET COMPRESSION = AUTO | LZO | SNAPPY | NONE SNAPPY_COMPRESSION = TRUE | FALSE BINARY_AS_TEXT = TRUE | FALSE USE_LOGICAL_TYPE = TRUE | FALSE TRIM_SPACE = TRUE | FALSE USE_VECTORIZED_SCANNER = TRUE | FALSE REPLACE_INVALID_CHARACTERS = TRUE | FALSE NULL_IF = ( '<string>' [ , '<string>' ... ] ) -- If TYPE = XML COMPRESSION = AUTO | GZIP | BZ2 | BROTLI | ZSTD | DEFLATE | RAW_DEFLATE | NONE IGNORE_UTF8_ERRORS = TRUE | FALSE PRESERVE_SPACE = TRUE | FALSE STRIP_OUTER_ELEMENT = TRUE | FALSE DISABLE_SNOWFLAKE_DATA = TRUE | FALSE DISABLE_AUTO_CONVERT = TRUE | FALSE REPLACE_INVALID_CHARACTERS = TRUE | FALSE SKIP_BYTE_ORDER_MARK = TRUE | FALSE
Directory table syntax¶
ALTER STAGE [ IF EXISTS ] <name> SET DIRECTORY = ( { ENABLE = TRUE | FALSE } )
ALTER STAGE [ IF EXISTS ] <name> REFRESH [ SUBPATH = '<relative-path>' ]
Parameters¶
name
Specifies the identifier for the stage to alter. If the identifier contains spaces or special characters, the entire string must be enclosed in double quotes. Identifiers enclosed in double quotes are also case-sensitive.
RENAME TO new_name
Specifies the new identifier for the stage; must be unique for the schema.
For more details, see Identifier requirements.
You can move the object to a different database and/or schema while optionally renaming the object. To do so, specify a qualified
new_name
value that includes the new database and/or schema name in the formdb_name.schema_name.object_name
orschema_name.object_name
, respectively.Note
The destination database and/or schema must already exist. In addition, an object with the same name cannot already exist in the new location; otherwise, the statement returns an error.
Moving an object to a managed access schema is prohibited unless the object owner (that is, the role that has the OWNERSHIP privilege on the object) also owns the target schema.
SET ...
Specifies the options/properties to set for the stage:
URL = ' ... '
, .STORAGE_INTEGRATION = ...
, .CREDENTIALS = ( ... )
, .ENCRYPTION = ( ... )
Modifies the cloud-specific URL, storage integration or credentials, and/or encryption for the external stage. For more details, see External Stage Parameters (in this topic).
TAG tag_name = 'tag_value' [ , tag_name = 'tag_value' , ... ]
Specifies the tag name and the tag string value.
The tag value is always a string, and the maximum number of characters for the tag value is 256.
For information about specifying tags in a statement, see Tag quotas for objects and columns.
COMMENT = 'string_literal'
Adds a comment or overwrites an existing comment for the stage.
FILE_FORMAT = ( FORMAT_NAME = 'file_format_name' )
or .FILE_FORMAT = ( TYPE = CSV | JSON | AVRO | ORC | PARQUET | XML | CUSTOM [ ... ] )
Modifies the file format for the stage, which can be either:
FORMAT_NAME = file_format_name
Specifies an existing file format object to use for the stage. The specified file format object determines the format type (CSV, JSON, etc.) and other format options for data files.
Note that no additional format options are specified in the string. Instead, the named file format object defines the other file format options used for loading/unloading data. For more information, see CREATE FILE FORMAT.
TYPE = CSV | JSON | AVRO | ORC | PARQUET | XML | CUSTOM [ ... ]
Specifies the file format type for the stage:
Loading data from a stage (using COPY INTO <table>) accommodates all of the supported file format types.
Unloading data into a stage (using COPY INTO <location>) accommodates CSV, JSON, or PARQUET.
If a file format type is specified, additional format-specific options can be modified. For more details, see Format Type Options (in this topic).
The
CUSTOM
format type specifies that the underlying stage holds unstructured data and can only be used with theFILE_PROCESSOR
copy option.Note
FORMAT_NAME
andTYPE
are mutually exclusive; you can only specify one or the other for a stage.
Note
Do not specify copy options using the CREATE STAGE, ALTER STAGE, CREATE TABLE, or ALTER TABLE commands. We recommend that you use the COPY INTO <table> command to specify copy options.
External stage parameters (externalStageParams
)¶
URL = 'cloud_specific_url'
If a stage does not have a URL, it is an internal stage
Warning
Modifying the
URL
parameter of a stage can break the following functionality for objects that rely on the stage:Pipe objects that leverage cloud messaging to trigger data loads (i.e. where
AUTO_INGEST = TRUE
).External tables that leverage cloud messaging to trigger metadata refreshes (i.e. where
AUTO_REFRESH = TRUE
).
Amazon S3
URL = 'protocol://bucket[/path/]'
Modifies the URL for the external location (existing S3 bucket) used to store data files for loading/unloading, where:
protocol
is one of the following:s3
refers to S3 storage in public AWS regions outside of China.s3china
refers to S3 storage in public AWS regions in China.s3gov
refers to S3 storage in government regions.
Accessing cloud storage in a government region using a storage integration is limited to Snowflake accounts hosted in the same government region.
Similarly, if you need to access cloud storage in a region in China, you can use a storage integration only from a Snowflake account hosted in the same region in China.
In these cases, use the CREDENTIALS parameter in the CREATE STAGE command (rather than using a storage integration) to provide the credentials for authentication.
bucket
is the name of the S3 bucket.Note that S3 buckets in non-public AWS regions, such as government regions, are not supported.
path
is an optional case-sensitive path for files in the cloud storage location (i.e. files have names that begin with a common string) that limits the set of files to load. Paths are alternatively called prefixes or folders by different cloud storage services.
Google Cloud Storage
URL = 'gcs://bucket[/path/]'
Modifies the URL for the external location (existing GCS bucket) used to store data files for loading/unloading, where:
bucket
is the name of the GCS bucket.path
is an optional case-sensitive path for files in the cloud storage location (i.e. files have names that begin with a common string) that limits the set of files to load. Paths are alternatively called prefixes or folders by different cloud storage services.
Microsoft Azure
URL = 'azure://account.blob.core.windows.net/container[/path/]'
Modifies the URL for the external location (existing Azure container) used to store data files for loading, where:
account
is the name of the Azure account (e.g.myaccount
). Use theblob.core.windows.net
endpoint for all supported types of Azure blob storage accounts, including Data Lake Storage Gen2.container
is the name of the Azure container (e.g.mycontainer
).path
is an optional case-sensitive path for files in the cloud storage location (i.e. files have names that begin with a common string) that limits the set of files to load. Paths are alternatively called prefixes or folders by different cloud storage services.
STORAGE_INTEGRATION = integration_name
or .CREDENTIALS = ( cloud_specific_credentials )
Required only if the Amazon S3, Google Cloud Storage, or Microsoft Azure is private; not required for public buckets/containers
Amazon S3
STORAGE_INTEGRATION = integration_name
Specifies the name of the storage integration used to delegate authentication responsibility for external cloud storage to a Snowflake identity and access management (IAM) entity. For more details, see CREATE STORAGE INTEGRATION.
Note
We highly recommend the use of storage integrations. This option avoids the need to supply cloud storage credentials using the CREDENTIALS parameter when creating stages or loading data.
CREDENTIALS = ( AWS_KEY_ID = 'string' AWS_SECRET_KEY = 'string' [ AWS_TOKEN = 'string' ] )
or .CREDENTIALS = ( AWS_ROLE = 'string' )
Modifies the security credentials for connecting to AWS and accessing the private S3 bucket where the files to load/unload are staged. For more information, see Configuring secure access to Amazon S3.
The credentials you specify depend on whether you associated the Snowflake access permissions for the bucket with an AWS IAM (Identity & Access Management) user or role:
IAM user: IAM credentials are required. Temporary (aka “scoped”) credentials are generated by AWS Security Token Service (STS) and consist of three components:
AWS_KEY_ID
AWS_SECRET_KEY
AWS_TOKEN
All three are required to access a private bucket. After a designated period of time, temporary credentials expire and can no longer be used. You must then generate a new set of valid temporary credentials.
Important
The COPY command also allows permanent (aka “long-term”) credentials to be used; however, for security reasons, Snowflake does not recommend using them. If you must use permanent credentials, Snowflake recommends periodically generating new permanent credentials for external stages.
IAM role: Omit the security credentials and access keys and, instead, identify the role using
AWS_ROLE
and specify the AWS role ARN (Amazon Resource Name).Important
The ability to use an AWS IAM role to access a private S3 bucket to load or unload data is now deprecated (i.e. support will be removed in a future release, TBD). We highly recommend modifying any existing S3 stages that use this feature to instead reference storage integration objects. For instructions, see Option 1: Configuring a Snowflake storage integration to access Amazon S3.
Google Cloud Storage
STORAGE_INTEGRATION = integration_name
Specifies the name of the storage integration used to delegate authentication responsibility for external cloud storage to a Snowflake identity and access management (IAM) entity. For more details, see CREATE STORAGE INTEGRATION.
Microsoft Azure
STORAGE_INTEGRATION = integration_name
Specifies the name of the storage integration used to delegate authentication responsibility for external cloud storage to a Snowflake identity and access management (IAM) entity. For more details, see CREATE STORAGE INTEGRATION.
Note
We highly recommend the use of storage integrations. This option avoids the need to supply cloud storage credentials using the CREDENTIALS parameter when creating stages or loading data.
CREDENTIALS = ( AZURE_SAS_TOKEN = 'string' )
Modifies the SAS (shared access signature) token for connecting to Azure and accessing the private container where the files containing loaded data are staged. Credentials are generated by Azure.
ENCRYPTION = ( cloud_specific_encryption )
Required only for loading from/unloading into encrypted files; not required if storage location and files are unencrypted
- Data loading:
Modifies the encryption settings used to decrypt encrypted files in the storage location and extract data.
- Data unloading:
Modifies the encryption settings used to encrypt files unloaded to the storage location.
Amazon S3
ENCRYPTION = ( [ TYPE = 'AWS_CSE' ] MASTER_KEY = 'string' | TYPE = 'AWS_SSE_S3' | TYPE = 'AWS_SSE_KMS' [ KMS_KEY_ID = 'string' ] | TYPE = 'NONE' )
TYPE = ...
Specifies the encryption type used. Possible values are:
AWS_CSE
: Client-side encryption (requires aMASTER_KEY
value). Currently, the client-side master key (https://csrc.nist.gov/glossary/term/master_key) you provide can only be a symmetric key. Note that, when aMASTER_KEY
value is provided, Snowflake assumesTYPE = AWS_CSE
(i.e. when aMASTER_KEY
value is provided,TYPE
is not required).AWS_SSE_S3
: Server-side encryption that requires no additional encryption settings.AWS_SSE_KMS
: Server-side encryption that accepts an optionalKMS_KEY_ID
value.
For more information about the encryption types, see the AWS documentation for client-side encryption (http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingClientSideEncryption.html) or server-side encryption (http://docs.aws.amazon.com/AmazonS3/latest/dev/serv-side-encryption.html).
NONE
: No encryption.
MASTER_KEY = 'string'
(applies toAWS_CSE
encryption only)Specifies the client-side master key used to encrypt the files in the bucket. The master key must be a 128-bit or 256-bit key in Base64-encoded form.
KMS_KEY_ID = 'string'
(applies toAWS_SSE_KMS
encryption only)Optionally specifies the ID for the AWS KMS-managed key used to encrypt files unloaded into the bucket. If no value is provided, your default KMS key ID is used to encrypt files on unload.
Note that this value is ignored for data loading.
Default:
NONE
Google Cloud Storage
ENCRYPTION = ( TYPE = 'GCS_SSE_KMS' [ KMS_KEY_ID = 'string' ] | TYPE = 'NONE' )
TYPE = ...
Specifies the encryption type used. Possible values are:
GCS_SSE_KMS
: Server-side encryption that accepts an optionalKMS_KEY_ID
value.For more information, see the Google Cloud documentation:
https://cloud.google.com/storage/docs/encryption/customer-managed-keys (https://cloud.google.com/storage/docs/encryption/customer-managed-keys)
https://cloud.google.com/storage/docs/encryption/using-customer-managed-keys (https://cloud.google.com/storage/docs/encryption/using-customer-managed-keys)
NONE
: No encryption.
KMS_KEY_ID = 'string'
(applies toGCS_SSE_KMS
encryption only)Optionally specifies the ID for the Cloud KMS-managed key that is used to encrypt files unloaded into the bucket. If no value is provided, your default KMS key ID set on the bucket is used to encrypt files on unload.
Note that this value is ignored for data loading. The load operation should succeed if the service account has sufficient permissions to decrypt data in the bucket.
Default:
NONE
Microsoft Azure
ENCRYPTION = ( TYPE = 'AZURE_CSE' MASTER_KEY = 'string' | TYPE = 'NONE' )
TYPE = ...
Specifies the encryption type used. Possible values are:
AZURE_CSE
: Client-side encryption (requires a MASTER_KEY value). For information, see the Client-side encryption information (https://docs.microsoft.com/en-us/azure/storage/common/storage-client-side-encryption) in the Microsoft Azure documentation.NONE
: No encryption.
MASTER_KEY = 'string'
(applies to AZURE_CSE encryption only)Specifies the client-side master key used to encrypt or decrypt files. The master key must be a 128-bit or 256-bit key in Base64-encoded form.
Default:
NONE
USE_PRIVATELINK_ENDPOINT = { TRUE | FALSE }
Specifies whether to use private connectivity for an Azure external stage. For information about using this parameter, see Azure private connectivity for external stages and Snowpipe automation.
If the external stage uses a storage integration, and that integration is configured for private connectivity, set this parameter to FALSE.
Directory table parameters¶
ENABLE = TRUE | FALSE
Specifies whether to add a directory table to the stage. When the value is TRUE, a directory table is added to the stage.
Note
Setting this parameter to TRUE is not supported for S3-compatible external stages. The metadata for S3-compatible external stages cannot be refreshed automatically.
Default:
FALSE
REFRESH
Accesses the staged data files referenced in the directory table definition and updates the table metadata:
New files in the path are added to the table metadata.
Changes to files in the path are updated in the table metadata.
Files no longer in the path are removed from the table metadata.
You can execute this command each time files are added to the stage, updated, or dropped. This step synchronizes the metadata with the latest set of associated files in the stage definition for the directory table.
SUBPATH = 'relative-path'
Optionally specify a relative path to refresh the metadata for a specific subset of the data files.
Format type options (formatTypeOptions
)¶
Depending on the file format type specified (FILE_FORMAT = ( TYPE = ... )
), you can include one or more of the following format-specific options (separated by blank spaces, commas, or new lines):
TYPE = CSV¶
COMPRESSION = AUTO | GZIP | BZ2 | BROTLI | ZSTD | DEFLATE | RAW_DEFLATE | NONE
- Use:
Data loading, data unloading, and external tables
- Definition:
When loading data, specifies the current compression algorithm for the data file. Snowflake uses this option to detect how an already-compressed data file was compressed so that the compressed data in the file can be extracted for loading.
When unloading data, compresses the data file using the specified compression algorithm.
- Values:
Supported Values
Notes
AUTO
When loading data, compression algorithm detected automatically, except for Brotli-compressed files, which cannot currently be detected automatically. When unloading data, files are automatically compressed using the default, which is gzip.
GZIP
BZ2
BROTLI
Must be specified when loading/unloading Brotli-compressed files.
ZSTD
Zstandard v0.8 (and higher) is supported.
DEFLATE
Deflate-compressed files (with zlib header, RFC1950).
RAW_DEFLATE
Raw Deflate-compressed files (without header, RFC1951).
NONE
When loading data, indicates that the files have not been compressed. When unloading data, specifies that the unloaded files are not compressed.
- Default:
AUTO
RECORD_DELIMITER = 'string' | NONE
- Use:
Data loading, data unloading, and external tables
- Definition:
One or more singlebyte or multibyte characters that separate records in an input file (data loading) or unloaded file (data unloading). Accepts common escape sequences or the following singlebyte or multibyte characters:
- Singlebyte characters:
Octal values (prefixed by
\\
) or hex values (prefixed by0x
or\x
). For example, for records delimited by the circumflex accent (^
) character, specify the octal (\\136
) or hex (0x5e
) value.- Multibyte characters:
Hex values (prefixed by
\x
). For example, for records delimited by the cent (¢
) character, specify the hex (\xC2\xA2
) value.The delimiter for RECORD_DELIMITER or FIELD_DELIMITER cannot be a substring of the delimiter for the other file format option (e.g.
FIELD_DELIMITER = 'aa' RECORD_DELIMITER = 'aabb'
).
The specified delimiter must be a valid UTF-8 character and not a random sequence of bytes. Also note that the delimiter is limited to a maximum of 20 characters.
Also accepts a value of
NONE
.- Default:
- Data loading:
New line character. Note that “new line” is logical such that
\r\n
will be understood as a new line for files on a Windows platform.- Data unloading:
New line character (
\n
).
FIELD_DELIMITER = 'string' | NONE
- Use:
Data loading, data unloading, and external tables
- Definition:
One or more singlebyte or multibyte characters that separate fields in an input file (data loading) or unloaded file (data unloading). Accepts common escape sequences or the following singlebyte or multibyte characters:
- Singlebyte characters:
Octal values (prefixed by
\\
) or hex values (prefixed by0x
or\x
). For example, for records delimited by the circumflex accent (^
) character, specify the octal (\\136
) or hex (0x5e
) value.- Multibyte characters:
Hex values (prefixed by
\x
). For example, for records delimited by the cent (¢
) character, specify the hex (\xC2\xA2
) value.The delimiter for RECORD_DELIMITER or FIELD_DELIMITER cannot be a substring of the delimiter for the other file format option (e.g.
FIELD_DELIMITER = 'aa' RECORD_DELIMITER = 'aabb'
).Note
For non-ASCII characters, you must use the hex byte sequence value to get a deterministic behavior.
The specified delimiter must be a valid UTF-8 character and not a random sequence of bytes. Also note that the delimiter is limited to a maximum of 20 characters.
Also accepts a value of
NONE
.- Default:
comma (
,
)
FILE_EXTENSION = 'string' | NONE
- Use:
Data unloading only
- Definition:
Specifies the extension for files unloaded to a stage. Accepts any extension. The user is responsible for specifying a file extension that can be read by any desired software or services.
- Default:
null, meaning the file extension is determined by the format type:
.csv[compression]
, wherecompression
is the extension added by the compression method, ifCOMPRESSION
is set.
Note
If the
SINGLE
copy option isTRUE
, then the COPY command unloads a file without a file extension by default. To specify a file extension, provide a file name and extension in theinternal_location
orexternal_location
path (e.g.copy into @stage/data.csv
).PARSE_HEADER = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether to use the first row headers in the data files to determine column names.
This file format option is applied to the following actions only:
Automatically detecting column definitions by using the INFER_SCHEMA function.
Loading CSV data into separate columns by using the INFER_SCHEMA function and MATCH_BY_COLUMN_NAME copy option.
If the option is set to TRUE, the first row headers will be used to determine column names. The default value FALSE will return column names as c*, where * is the position of the column.
Note
This option isn’t supported for external tables.
The SKIP_HEADER option isn’t supported if you set
PARSE_HEADER = TRUE
.
Default:
FALSE
SKIP_HEADER = integer
- Use:
Data loading and external tables
- Definition:
Number of lines at the start of the file to skip.
Note that SKIP_HEADER does not use the RECORD_DELIMITER or FIELD_DELIMITER values to determine what a header line is; rather, it simply skips the specified number of CRLF (Carriage Return, Line Feed)-delimited lines in the file. RECORD_DELIMITER and FIELD_DELIMITER are then used to determine the rows of data to load.
- Default:
0
SKIP_BLANK_LINES = TRUE | FALSE
- Use:
Data loading and external tables
- Definition:
Boolean that specifies to skip any blank lines encountered in the data files; otherwise, blank lines produce an end-of-record error (default behavior).
Default:
FALSE
DATE_FORMAT = 'string' | AUTO
- Use:
Data loading and unloading
- Definition:
Defines the format of date values in the data files (data loading) or table (data unloading). If a value is not specified or is
AUTO
, the value for the DATE_INPUT_FORMAT (data loading) or DATE_OUTPUT_FORMAT (data unloading) parameter is used.- Default:
AUTO
TIME_FORMAT = 'string' | AUTO
- Use:
Data loading and unloading
- Definition:
Defines the format of time values in the data files (data loading) or table (data unloading). If a value is not specified or is
AUTO
, the value for the TIME_INPUT_FORMAT (data loading) or TIME_OUTPUT_FORMAT (data unloading) parameter is used.- Default:
AUTO
TIMESTAMP_FORMAT = string' | AUTO
- Use:
Data loading and unloading
- Definition:
Defines the format of timestamp values in the data files (data loading) or table (data unloading). If a value is not specified or is
AUTO
, the value for the TIMESTAMP_INPUT_FORMAT (data loading) or TIMESTAMP_OUTPUT_FORMAT (data unloading) parameter is used.- Default:
AUTO
BINARY_FORMAT = HEX | BASE64 | UTF8
- Use:
Data loading and unloading
- Definition:
Defines the encoding format for binary input or output. The option can be used when loading data into or unloading data from binary columns in a table.
- Default:
HEX
ESCAPE = 'character' | NONE
- Use:
Data loading and unloading
- Definition:
A singlebyte character string used as the escape character for enclosed or unenclosed field values. An escape character invokes an alternative interpretation on subsequent characters in a character sequence. You can use the ESCAPE character to interpret instances of the
FIELD_OPTIONALLY_ENCLOSED_BY
character in the data as literals.Accepts common escape sequences, octal values, or hex values.
- Loading data:
Specifies the escape character for enclosed fields only. Specify the character used to enclose fields by setting
FIELD_OPTIONALLY_ENCLOSED_BY
.Note
This file format option supports singlebyte characters only. Note that UTF-8 character encoding represents high-order ASCII characters as multibyte characters. If your data file is encoded with the UTF-8 character set, you cannot specify a high-order ASCII character as the option value.
In addition, if you specify a high-order ASCII character, we recommend that you set the
ENCODING = 'string'
file format option as the character encoding for your data files to ensure the character is interpreted correctly.- Unloading data:
If this option is set, it overrides the escape character set for
ESCAPE_UNENCLOSED_FIELD
.- Default:
NONE
ESCAPE_UNENCLOSED_FIELD = 'character' | NONE
- Use:
Data loading, data unloading, and external tables
- Definition:
A singlebyte character string used as the escape character for unenclosed field values only. An escape character invokes an alternative interpretation on subsequent characters in a character sequence. You can use the ESCAPE character to interpret instances of the
FIELD_DELIMITER
orRECORD_DELIMITER
characters in the data as literals. The escape character can also be used to escape instances of itself in the data.Accepts common escape sequences, octal values, or hex values.
- Loading data:
Specifies the escape character for unenclosed fields only.
Note
The default value is
\\
. If a row in a data file ends in the backslash (\
) character, this character escapes the newline or carriage return character specified for theRECORD_DELIMITER
file format option. As a result, the load operation treats this row and the next row as a single row of data. To avoid this issue, set the value toNONE
.This file format option supports singlebyte characters only. Note that UTF-8 character encoding represents high-order ASCII characters as multibyte characters. If your data file is encoded with the UTF-8 character set, you cannot specify a high-order ASCII character as the option value.
In addition, if you specify a high-order ASCII character, we recommend that you set the
ENCODING = 'string'
file format option as the character encoding for your data files to ensure the character is interpreted correctly.
- Unloading data:
If
ESCAPE
is set, the escape character set for that file format option overrides this option.- Default:
backslash (
\\
)
TRIM_SPACE = TRUE | FALSE
- Use:
Data loading and external tables
- Definition:
Boolean that specifies whether to remove white space from fields.
For example, if your external database software encloses fields in quotes, but inserts a leading space, Snowflake reads the leading space rather than the opening quotation character as the beginning of the field (i.e. the quotation marks are interpreted as part of the string of field data). Set this option to
TRUE
to remove undesirable spaces during the data load.As another example, if leading or trailing spaces surround quotes that enclose strings, you can remove the surrounding spaces using this option and the quote character using the
FIELD_OPTIONALLY_ENCLOSED_BY
option. Note that any spaces within the quotes are preserved. For example, assumingFIELD_DELIMITER = '|'
andFIELD_OPTIONALLY_ENCLOSED_BY = '"'
:|"Hello world"| /* loads as */ >Hello world< |" Hello world "| /* loads as */ > Hello world < | "Hello world" | /* loads as */ >Hello world<
(the brackets in this example are not loaded; they are used to demarcate the beginning and end of the loaded strings)
- Default:
FALSE
FIELD_OPTIONALLY_ENCLOSED_BY = 'character' | NONE
- Use:
Data loading, data unloading, and external tables
- Definition:
Character used to enclose strings. Value can be
NONE
, single quote character ('
), or double quote character ("
). To use the single quote character, use the octal or hex representation (0x27
) or the double single-quoted escape (''
).- Data unloading only:
When a field in the source table contains this character, Snowflake escapes it using the same character for unloading. For example, if the value is the double quote character and a field contains the string
A "B" C
, Snowflake escapes the double quotes for unloading as follows:A ""B"" C
- Default:
NONE
NULL_IF = ( 'string1' [ , 'string2' , ... ] )
- Use:
Data loading, data unloading, and external tables
- Definition:
String used to convert to and from SQL NULL:
When loading data, Snowflake replaces these values in the data load source with SQL NULL. To specify more than one string, enclose the list of strings in parentheses and use commas to separate each value.
Note that Snowflake converts all instances of the value to NULL, regardless of the data type. For example, if
2
is specified as a value, all instances of2
as either a string or number are converted.For example:
NULL_IF = ('\N', 'NULL', 'NUL', '')
Note that this option can include empty strings.
When unloading data, Snowflake converts SQL NULL values to the first value in the list.
- Default:
\\N
(i.e. NULL, which assumes theESCAPE_UNENCLOSED_FIELD
value is\\
)
ERROR_ON_COLUMN_COUNT_MISMATCH = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether to generate a parsing error if the number of delimited columns (i.e. fields) in an input file does not match the number of columns in the corresponding table.
If set to
FALSE
, an error is not generated and the load continues. If the file is successfully loaded:If the input file contains records with more fields than columns in the table, the matching fields are loaded in order of occurrence in the file and the remaining fields are not loaded.
If the input file contains records with fewer fields than columns in the table, the non-matching columns in the table are loaded with NULL values.
This option assumes all the records within the input file are the same length (i.e. a file containing records of varying length return an error regardless of the value specified for this parameter).
- Default:
TRUE
Note
When transforming data during loading (i.e. using a query as the source for the COPY command), this option is ignored. There is no requirement for your data files to have the same number and ordering of columns as your target table.
REPLACE_INVALID_CHARACTERS = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether to replace invalid UTF-8 characters with the Unicode replacement character (
�
).
If set to
TRUE
, Snowflake replaces invalid UTF-8 characters with the Unicode replacement character.If set to
FALSE
, the load operation produces an error when invalid UTF-8 character encoding is detected.- Default:
FALSE
EMPTY_FIELD_AS_NULL = TRUE | FALSE
- Use:
Data loading, data unloading, and external tables
- Definition:
When loading data, specifies whether to insert SQL NULL for empty fields in an input file, which are represented by two successive delimiters (e.g.
,,
).If set to
FALSE
, Snowflake attempts to cast an empty field to the corresponding column type. An empty string is inserted into columns of type STRING. For other column types, the COPY command produces an error.When unloading data, this option is used in combination with
FIELD_OPTIONALLY_ENCLOSED_BY
. WhenFIELD_OPTIONALLY_ENCLOSED_BY = NONE
, settingEMPTY_FIELD_AS_NULL = FALSE
specifies to unload empty strings in tables to empty string values without quotes enclosing the field values.If set to
TRUE
,FIELD_OPTIONALLY_ENCLOSED_BY
must specify a character to enclose strings.
- Default:
TRUE
SKIP_BYTE_ORDER_MARK = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether to skip the BOM (byte order mark), if present in a data file. A BOM is a character code at the beginning of a data file that defines the byte order and encoding form.
If set to
FALSE
, Snowflake recognizes any BOM in data files, which could result in the BOM either causing an error or being merged into the first column in the table.- Default:
TRUE
ENCODING = 'string'
- Use:
Data loading and external tables
- Definition:
String (constant) that specifies the character set of the source data when loading data into a table.
Character Set
ENCODING
ValueSupported Languages
Notes
Big5
BIG5
Traditional Chinese
EUC-JP
EUCJP
Japanese
EUC-KR
EUCKR
Korean
GB18030
GB18030
Chinese
IBM420
IBM420
Arabic
IBM424
IBM424
Hebrew
IBM949
IBM949
Korean
ISO-2022-CN
ISO2022CN
Simplified Chinese
ISO-2022-JP
ISO2022JP
Japanese
ISO-2022-KR
ISO2022KR
Korean
ISO-8859-1
ISO88591
Danish, Dutch, English, French, German, Italian, Norwegian, Portuguese, Swedish
ISO-8859-2
ISO88592
Czech, Hungarian, Polish, Romanian
ISO-8859-5
ISO88595
Russian
ISO-8859-6
ISO88596
Arabic
ISO-8859-7
ISO88597
Greek
ISO-8859-8
ISO88598
Hebrew
ISO-8859-9
ISO88599
Turkish
ISO-8859-15
ISO885915
Danish, Dutch, English, French, German, Italian, Norwegian, Portuguese, Swedish
Identical to ISO-8859-1 except for 8 characters, including the Euro currency symbol.
KOI8-R
KOI8R
Russian
Shift_JIS
SHIFTJIS
Japanese
UTF-8
UTF8
All languages
For loading data from delimited files (CSV, TSV, etc.), UTF-8 is the default. . . For loading data from all other supported file formats (JSON, Avro, etc.), as well as unloading data, UTF-8 is the only supported character set.
UTF-16
UTF16
All languages
UTF-16BE
UTF16BE
All languages
UTF-16LE
UTF16LE
All languages
UTF-32
UTF32
All languages
UTF-32BE
UTF32BE
All languages
UTF-32LE
UTF32LE
All languages
windows-874
WINDOWS874
Thai
windows-949
WINDOWS949
Korean
windows-1250
WINDOWS1250
Czech, Hungarian, Polish, Romanian
windows-1251
WINDOWS1251
Russian
windows-1252
WINDOWS1252
Danish, Dutch, English, French, German, Italian, Norwegian, Portuguese, Swedish
windows-1253
WINDOWS1253
Greek
windows-1254
WINDOWS1254
Turkish
windows-1255
WINDOWS1255
Hebrew
windows-1256
WINDOWS1256
Arabic
- Default:
UTF8
Note
Snowflake stores all data internally in the UTF-8 character set. The data is converted into UTF-8 before it is loaded into Snowflake.
TYPE = JSON¶
COMPRESSION = AUTO | GZIP | BZ2 | BROTLI | ZSTD | DEFLATE | RAW_DEFLATE | NONE
- Use:
Data loading and external tables
- Definition:
When loading data, specifies the current compression algorithm for the data file. Snowflake uses this option to detect how an already-compressed data file was compressed so that the compressed data in the file can be extracted for loading.
When unloading data, compresses the data file using the specified compression algorithm.
- Values:
Supported Values
Notes
AUTO
When loading data, compression algorithm detected automatically, except for Brotli-compressed files, which cannot currently be detected automatically. When unloading data, files are automatically compressed using the default, which is gzip.
GZIP
BZ2
BROTLI
Must be specified if loading/unloading Brotli-compressed files.
ZSTD
Zstandard v0.8 (and higher) is supported.
DEFLATE
Deflate-compressed files (with zlib header, RFC1950).
RAW_DEFLATE
Raw Deflate-compressed files (without header, RFC1951).
NONE
When loading data, indicates that the files have not been compressed. When unloading data, specifies that the unloaded files are not compressed.
- Default:
AUTO
DATE_FORMAT = 'string' | AUTO
- Use:
Data loading only
- Definition:
Defines the format of date string values in the data files. If a value is not specified or is
AUTO
, the value for the DATE_INPUT_FORMAT parameter is used.This file format option is applied to the following actions only:
Loading JSON data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
Loading JSON data into separate columns by specifying a query in the COPY statement (i.e. COPY transformation).
- Default:
AUTO
TIME_FORMAT = 'string' | AUTO
- Use:
Data loading only
- Definition:
Defines the format of time string values in the data files. If a value is not specified or is
AUTO
, the value for the TIME_INPUT_FORMAT parameter is used.This file format option is applied to the following actions only:
Loading JSON data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
Loading JSON data into separate columns by specifying a query in the COPY statement (i.e. COPY transformation).
- Default:
AUTO
TIMESTAMP_FORMAT = string' | AUTO
- Use:
Data loading only
- Definition:
Defines the format of timestamp string values in the data files. If a value is not specified or is
AUTO
, the value for the TIMESTAMP_INPUT_FORMAT parameter is used.This file format option is applied to the following actions only:
Loading JSON data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
Loading JSON data into separate columns by specifying a query in the COPY statement (i.e. COPY transformation).
- Default:
AUTO
BINARY_FORMAT = HEX | BASE64 | UTF8
- Use:
Data loading only
- Definition:
Defines the encoding format for binary string values in the data files. The option can be used when loading data into binary columns in a table.
This file format option is applied to the following actions only:
Loading JSON data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
Loading JSON data into separate columns by specifying a query in the COPY statement (i.e. COPY transformation).
- Default:
HEX
TRIM_SPACE = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether to remove leading and trailing white space from strings.
For example, if your external database software encloses fields in quotes, but inserts a leading space, Snowflake reads the leading space rather than the opening quotation character as the beginning of the field (i.e. the quotation marks are interpreted as part of the string of field data). Set this option to
TRUE
to remove undesirable spaces during the data load.This file format option is applied to the following actions only when loading JSON data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
- Default:
FALSE
NULL_IF = ( 'string1' [ , 'string2' , ... ] )
- Use:
Data loading only
- Definition:
String used to convert to and from SQL NULL. Snowflake replaces these strings in the data load source with SQL NULL. To specify more than one string, enclose the list of strings in parentheses and use commas to separate each value.
This file format option is applied to the following actions only when loading JSON data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
Note that Snowflake converts all instances of the value to NULL, regardless of the data type. For example, if
2
is specified as a value, all instances of2
as either a string or number are converted.For example:
NULL_IF = ('\N', 'NULL', 'NUL', '')
Note that this option can include empty strings.
- Default:
\\N
(i.e. NULL, which assumes theESCAPE_UNENCLOSED_FIELD
value is\\
)
FILE_EXTENSION = 'string' | NONE
- Use:
Data unloading only
- Definition:
Specifies the extension for files unloaded to a stage. Accepts any extension. The user is responsible for specifying a file extension that can be read by any desired software or services.
- Default:
null, meaning the file extension is determined by the format type:
.json[compression]
, wherecompression
is the extension added by the compression method, ifCOMPRESSION
is set.
ENABLE_OCTAL = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that enables parsing of octal numbers.
- Default:
FALSE
ALLOW_DUPLICATE = TRUE | FALSE
- Use:
Data loading and external tables
- Definition:
Boolean that specifies to allow duplicate object field names (only the last one will be preserved).
- Default:
FALSE
STRIP_OUTER_ARRAY = TRUE | FALSE
- Use:
Data loading and external tables
- Definition:
Boolean that instructs the JSON parser to remove outer brackets (i.e.
[ ]
).- Default:
FALSE
STRIP_NULL_VALUES = TRUE | FALSE
- Use:
Data loading and external tables
- Definition:
Boolean that instructs the JSON parser to remove object fields or array elements containing
null
values. For example, when set toTRUE
:Before
After
[null]
[]
[null,null,3]
[,,3]
{"a":null,"b":null,"c":123}
{"c":123}
{"a":[1,null,2],"b":{"x":null,"y":88}}
{"a":[1,,2],"b":{"y":88}}
- Default:
FALSE
REPLACE_INVALID_CHARACTERS = TRUE | FALSE
- Use:
Data loading and external table
- Definition:
Boolean that specifies whether to replace invalid UTF-8 characters with the Unicode replacement character (
�
). This option performs a one-to-one character replacement.- Values:
If set to
TRUE
, Snowflake replaces invalid UTF-8 characters with the Unicode replacement character.If set to
FALSE
, the load operation produces an error when invalid UTF-8 character encoding is detected.- Default:
FALSE
IGNORE_UTF8_ERRORS = TRUE | FALSE
- Use:
Data loading and external table
- Definition:
Boolean that specifies whether UTF-8 encoding errors produce error conditions. It is an alternative syntax for
REPLACE_INVALID_CHARACTERS
.- Values:
If set to
TRUE
, any invalid UTF-8 sequences are silently replaced with the Unicode characterU+FFFD
(i.e. “replacement character”).If set to
FALSE
, the load operation produces an error when invalid UTF-8 character encoding is detected.- Default:
FALSE
SKIP_BYTE_ORDER_MARK = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether to skip the BOM (byte order mark), if present in a data file. A BOM is a character code at the beginning of a data file that defines the byte order and encoding form.
If set to
FALSE
, Snowflake recognizes any BOM in data files, which could result in the BOM either causing an error or being merged into the first column in the table.- Default:
TRUE
TYPE = AVRO¶
COMPRESSION = AUTO | GZIP | BROTLI | ZSTD | DEFLATE | RAW_DEFLATE | NONE
- Use:
Data loading only
- Definition:
When loading data, specifies the current compression algorithm for the data file. Snowflake uses this option to detect how an already-compressed data file was compressed so that the compressed data in the file can be extracted for loading.
When unloading data, compresses the data file using the specified compression algorithm.
- Values:
Supported Values
Notes
AUTO
When loading data, compression algorithm detected automatically, except for Brotli-compressed files, which cannot currently be detected automatically. When unloading data, files are automatically compressed using the default, which is gzip.
GZIP
BROTLI
Must be specified if loading/unloading Brotli-compressed files.
ZSTD
Zstandard v0.8 (and higher) is supported.
DEFLATE
Deflate-compressed files (with zlib header, RFC1950).
RAW_DEFLATE
Raw Deflate-compressed files (without header, RFC1951).
NONE
When loading data, indicates that the files have not been compressed. When unloading data, specifies that the unloaded files are not compressed.
- Default:
AUTO
.
Note
We recommend that you use the default AUTO
option because it will determine both the file and codec compression. Specifying a compression option refers to the compression of files, not the compression of blocks (codecs).
TRIM_SPACE = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether to remove leading and trailing white space from strings.
For example, if your external database software encloses fields in quotes, but inserts a leading space, Snowflake reads the leading space rather than the opening quotation character as the beginning of the field (i.e. the quotation marks are interpreted as part of the string of field data). Set this option to
TRUE
to remove undesirable spaces during the data load.This file format option is applied to the following actions only when loading Avro data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
- Default:
FALSE
REPLACE_INVALID_CHARACTERS = TRUE | FALSE
- Use:
Data loading and external table
- Definition:
Boolean that specifies whether to replace invalid UTF-8 characters with the Unicode replacement character (
�
). This option performs a one-to-one character replacement.- Values:
If set to
TRUE
, Snowflake replaces invalid UTF-8 characters with the Unicode replacement character.If set to
FALSE
, the load operation produces an error when invalid UTF-8 character encoding is detected.- Default:
FALSE
NULL_IF = ( 'string1' [ , 'string2' , ... ] )
- Use:
Data loading only
- Definition:
String used to convert to and from SQL NULL. Snowflake replaces these strings in the data load source with SQL NULL. To specify more than one string, enclose the list of strings in parentheses and use commas to separate each value.
This file format option is applied to the following actions only when loading Avro data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
Note that Snowflake converts all instances of the value to NULL, regardless of the data type. For example, if
2
is specified as a value, all instances of2
as either a string or number are converted.For example:
NULL_IF = ('\N', 'NULL', 'NUL', '')
Note that this option can include empty strings.
- Default:
\\N
(i.e. NULL, which assumes theESCAPE_UNENCLOSED_FIELD
value is\\
)
TYPE = ORC¶
TRIM_SPACE = TRUE | FALSE
- Use:
Data loading and external tables
- Definition:
Boolean that specifies whether to remove leading and trailing white space from strings.
For example, if your external database software encloses fields in quotes, but inserts a leading space, Snowflake reads the leading space rather than the opening quotation character as the beginning of the field (i.e. the quotation marks are interpreted as part of the string of field data). Set this option to
TRUE
to remove undesirable spaces during the data load.This file format option is applied to the following actions only when loading Orc data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
- Default:
FALSE
REPLACE_INVALID_CHARACTERS = TRUE | FALSE
- Use:
Data loading and external table
- Definition:
Boolean that specifies whether to replace invalid UTF-8 characters with the Unicode replacement character (
�
). This option performs a one-to-one character replacement.- Values:
If set to
TRUE
, Snowflake replaces invalid UTF-8 characters with the Unicode replacement character.If set to
FALSE
, the load operation produces an error when invalid UTF-8 character encoding is detected.- Default:
FALSE
NULL_IF = ( 'string1' [ , 'string2' , ... ] )
- Use:
Data loading and external tables
- Definition:
String used to convert to and from SQL NULL. Snowflake replaces these strings in the data load source with SQL NULL. To specify more than one string, enclose the list of strings in parentheses and use commas to separate each value.
This file format option is applied to the following actions only when loading Orc data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
Note that Snowflake converts all instances of the value to NULL, regardless of the data type. For example, if
2
is specified as a value, all instances of2
as either a string or number are converted.For example:
NULL_IF = ('\N', 'NULL', 'NUL', '')
Note that this option can include empty strings.
- Default:
\\N
(i.e. NULL, which assumes theESCAPE_UNENCLOSED_FIELD
value is\\
)
TYPE = PARQUET¶
COMPRESSION = AUTO | LZO | SNAPPY | NONE
- Use:
Data loading, data unloading, and external tables
- Definition:
When loading data, specifies the current compression algorithm for columns in the Parquet files.
When unloading data, compresses the data file using the specified compression algorithm.
- Values:
Supported Values
Notes
AUTO
When loading data, compression algorithm detected automatically. Supports the following compression algorithms: Brotli, gzip, Lempel-Ziv-Oberhumer (LZO), LZ4, Snappy, or Zstandard v0.8 (and higher). . When unloading data, unloaded files are compressed using the Snappy (https://google.github.io/snappy/) compression algorithm by default.
LZO
When unloading data, files are compressed using the Snappy algorithm by default. If unloading data to LZO-compressed files, specify this value.
SNAPPY
When unloading data, files are compressed using the Snappy algorithm by default. You can optionally specify this value.
NONE
When loading data, indicates that the files have not been compressed. When unloading data, specifies that the unloaded files are not compressed.
- Default:
AUTO
SNAPPY_COMPRESSION = TRUE | FALSE
- Use:
Data unloading only
Supported Values
Notes
AUTO
Unloaded files are compressed using the Snappy (https://google.github.io/snappy/) compression algorithm by default.
SNAPPY
May be specified if unloading Snappy-compressed files.
NONE
When loading data, indicates that the files have not been compressed. When unloading data, specifies that the unloaded files are not compressed.
- Definition:
Boolean that specifies whether unloaded file(s) are compressed using the SNAPPY algorithm.
Note
Deprecated. Use
COMPRESSION = SNAPPY
instead.- Limitations:
Only supported for data unloading operations.
- Default:
TRUE
BINARY_AS_TEXT = TRUE | FALSE
- Use:
Data loading and external tables
- Definition:
Boolean that specifies whether to interpret columns with no defined logical data type as UTF-8 text. When set to
FALSE
, Snowflake interprets these columns as binary data.- Default:
TRUE
Note
Snowflake recommends that you set BINARY_AS_TEXT to FALSE to avoid any potential conversion issues.
TRIM_SPACE = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether to remove leading and trailing white space from strings.
For example, if your external database software encloses fields in quotes, but inserts a leading space, Snowflake reads the leading space rather than the opening quotation character as the beginning of the field (i.e. the quotation marks are interpreted as part of the string of field data). Set this option to
TRUE
to remove undesirable spaces during the data load.This file format option is applied to the following actions only when loading Parquet data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
- Default:
FALSE
USE_LOGICAL_TYPE = TRUE | FALSE
- Use:
Data loading, data querying in staged files, and schema detection.
- Definition:
Boolean that specifies whether to use Parquet logical types. With this file format option, Snowflake can interpret Parquet logical types during data loading. For more information, see Parquet Logical Type Definitions (https://github.com/apache/parquet-format/blob/master/LogicalTypes.md). To enable Parquet logical types, set USE_LOGICAL_TYPE as TRUE when you create a new file format option.
- Limitations:
Not supported for data unloading.
USE_VECTORIZED_SCANNER = TRUE | FALSE
- Use:
Data loading and data querying in staged files
- Definition:
Boolean that specifies whether to use a vectorized scanner for loading Parquet files.
- Default:
FALSE
. In a future BCR, the default value will beTRUE
.
Using the vectorized scanner can significantly reduce the latency for loading Parquet files, because this scanner is well suited for the columnar format of a Parquet (https://parquet.apache.org/docs/file-format/) file. The scanner only downloads relevant sections of the Parquet file into memory, such as the subset of selected columns.
You can only enable the vectorized scanner if the following conditions are met:
The
ON_ERROR
option must be set toABORT_STATEMENT
orSKIP_FILE
.The other values,
CONTINUE
,SKIP_FILE_num
,'SKIP_FILE_num%'
are not supported.
If
USE_VECTORIZED_SCANNER
is set toTRUE
, the vectorized scanner has the following behaviors:The
BINARY_AS_TEXT
option is always treated asFALSE
and theUSE_LOGICAL_TYPE
option is always treated asTRUE
, no matter what the actual value is being set to.The vectorized scanner supports Parquet map types. The output of scanning a map type is as follows:
"my_map": { "k1": "v1", "k2": "v2" }
The vectorized scanner shows
NULL
values in the output, as the following example demonstrates:"person": { "name": "Adam", "nickname": null, "age": 34, "phone_numbers": [ "1234567890", "0987654321", null, "6781234590" ] }
The vectorized scanner handles Time and Timestamp as follows:
Parquet
Snowflake vectorized scanner
TimeType(isAdjustedToUtc=True/False, unit=MILLIS/MICROS/NANOS)
TIME
TimestampType(isAdjustedToUtc=True, unit=MILLIS/MICROS/NANOS)
TIMESTAMP_LTZ
TimestampType(isAdjustedToUtc=False, unit=MILLIS/MICROS/NANOS)
TIMESTAMP_NTZ
INT96
TIMESTAMP_LTZ
If
USE_VECTORIZED_SCANNER
is set toFALSE
, the scanner has the following behaviors:This option does not support Parquet maps. The output of scanning a map type is as follows:
"my_map": { "key_value": [ { "key": "k1", "value": "v1" }, { "key": "k2", "value": "v2" } ] }
This option does not explicitly show
NULL
values in the scan output, as the following example demonstrates:"person": { "name": "Adam", "age": 34 "phone_numbers": [ "1234567890", "0987654321", "6781234590" ] }
This option handles Time and Timestamp as follows:
Parquet
When USE_LOGICAL_TYPE = TRUE
When USE_LOGICAL_TYPE = FALSE
TimeType(isAdjustedToUtc=True/False, unit=MILLIS/MICROS)
TIME
TIME (If ConvertedType present)
INTEGER (If ConvertedType not present)
TimeType(isAdjustedToUtc=True/False, unit=NANOS)
TIME
INTEGER
TimestampType(isAdjustedToUtc=True, unit=MILLIS/MICROS)
TIMESTAMP_LTZ
TIMESTAMP_NTZ
TimestampType(isAdjustedToUtc=True, unit=NANOS)
TIMESTAMP_LTZ
INTEGER
TimestampType(isAdjustedToUtc=False, unit=MILLIS/MICROS)
TIMESTAMP_NTZ
TIMESTAMP_LTZ (If ConvertedType present)
INTEGER (If ConvertedType not present)
TimestampType(isAdjustedToUtc=False, unit=NANOS)
TIMESTAMP_NTZ
INTEGER
INT96
TIMESTAMP_NTZ
TIMESTAMP_NTZ
REPLACE_INVALID_CHARACTERS = TRUE | FALSE
- Use:
Data loading and external table
- Definition:
Boolean that specifies whether to replace invalid UTF-8 characters with the Unicode replacement character (
�
). This option performs a one-to-one character replacement.- Values:
If set to
TRUE
, Snowflake replaces invalid UTF-8 characters with the Unicode replacement character.If set to
FALSE
, the load operation produces an error when invalid UTF-8 character encoding is detected.- Default:
FALSE
NULL_IF = ( 'string1' [ , 'string2' , ... ] )
- Use:
Data loading only
- Definition:
String used to convert to and from SQL NULL. Snowflake replaces these strings in the data load source with SQL NULL. To specify more than one string, enclose the list of strings in parentheses and use commas to separate each value.
This file format option is applied to the following actions only when loading Parquet data into separate columns using the MATCH_BY_COLUMN_NAME copy option.
Note that Snowflake converts all instances of the value to NULL, regardless of the data type. For example, if
2
is specified as a value, all instances of2
as either a string or number are converted.For example:
NULL_IF = ('\N', 'NULL', 'NUL', '')
Note that this option can include empty strings.
- Default:
\\N
(i.e. NULL, which assumes theESCAPE_UNENCLOSED_FIELD
value is\\
)
TYPE = XML¶
COMPRESSION = AUTO | GZIP | BZ2 | BROTLI | ZSTD | DEFLATE | RAW_DEFLATE | NONE
- Use:
Data loading only
- Definition:
When loading data, specifies the current compression algorithm for the data file. Snowflake uses this option to detect how an already-compressed data file was compressed so that the compressed data in the file can be extracted for loading.
When unloading data, compresses the data file using the specified compression algorithm.
- Values:
Supported Values
Notes
AUTO
When loading data, compression algorithm detected automatically, except for Brotli-compressed files, which cannot currently be detected automatically. When unloading data, files are automatically compressed using the default, which is gzip.
GZIP
BZ2
BROTLI
Must be specified if loading/unloading Brotli-compressed files.
ZSTD
Zstandard v0.8 (and higher) is supported.
DEFLATE
Deflate-compressed files (with zlib header, RFC1950).
RAW_DEFLATE
Raw Deflate-compressed files (without header, RFC1951).
NONE
When loading data, indicates that the files have not been compressed. When unloading data, specifies that the unloaded files are not compressed.
- Default:
AUTO
IGNORE_UTF8_ERRORS = TRUE | FALSE
- Use:
Data loading and external table
- Definition:
Boolean that specifies whether UTF-8 encoding errors produce error conditions. It is an alternative syntax for
REPLACE_INVALID_CHARACTERS
.- Values:
If set to
TRUE
, any invalid UTF-8 sequences are silently replaced with the Unicode characterU+FFFD
(i.e. “replacement character”).If set to
FALSE
, the load operation produces an error when invalid UTF-8 character encoding is detected.- Default:
FALSE
PRESERVE_SPACE = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether the XML parser preserves leading and trailing spaces in element content.
- Default:
FALSE
STRIP_OUTER_ELEMENT = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether the XML parser strips out the outer XML element, exposing 2nd level elements as separate documents.
- Default:
FALSE
DISABLE_SNOWFLAKE_DATA = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether the XML parser disables recognition of Snowflake semi-structured data tags.
- Default:
FALSE
DISABLE_AUTO_CONVERT = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether the XML parser disables automatic conversion of numeric and Boolean values from text to native representation.
- Default:
FALSE
REPLACE_INVALID_CHARACTERS = TRUE | FALSE
- Use:
Data loading and external table
- Definition:
Boolean that specifies whether to replace invalid UTF-8 characters with the Unicode replacement character (
�
). This option performs a one-to-one character replacement.- Values:
If set to
TRUE
, Snowflake replaces invalid UTF-8 characters with the Unicode replacement character.If set to
FALSE
, the load operation produces an error when invalid UTF-8 character encoding is detected.- Default:
FALSE
SKIP_BYTE_ORDER_MARK = TRUE | FALSE
- Use:
Data loading only
- Definition:
Boolean that specifies whether to skip any BOM (byte order mark) present in an input file. A BOM is a character code at the beginning of a data file that defines the byte order and encoding form.
If set to
FALSE
, Snowflake recognizes any BOM in data files, which could result in the BOM either causing an error or being merged into the first column in the table.- Default:
TRUE
Access control requirements¶
A role used to execute this SQL command must have the following privileges at a minimum:
Privilege |
Object |
Notes |
---|---|---|
OWNERSHIP |
Stage |
Required to alter the stage properties and to enable or disable a directory table on the stage using ALTER STAGE … SET DIRECTORY. OWNERSHIP is a special privilege on an object that is automatically granted to the role that created the object, but can also be transferred using the GRANT OWNERSHIP command to a different role by the owning role (or any role with the MANAGE GRANTS privilege). |
WRITE |
Stage |
Required to refresh the metadata using ALTER STAGE … REFRESH. |
The USAGE privilege on the parent database and schema are required to perform operations on any object in a schema.
For instructions on creating a custom role with a specified set of privileges, see Creating custom roles.
For general information about roles and privilege grants for performing SQL actions on securable objects, see Overview of Access Control.
Usage notes¶
Regarding metadata:
Attention
Customers should ensure that no personal data (other than for a User object), sensitive data, export-controlled data, or other regulated data is entered as metadata when using the Snowflake service. For more information, see Metadata fields in Snowflake.
Examples¶
Rename my_int_stage
to new_int_stage
:
ALTER STAGE my_int_stage RENAME TO new_int_stage;
Alter my_ext_stage
(created in the CREATE STAGE examples) to change the URL to reference a sub-folder named new
in the
files
folder. If a COPY INTO <table> command that references this stage encounters a data error on any of the
records, it skips the file. All other copy options are set to the default values.
If the S3 bucket is in a region in China, use the s3china://
protocol for the URL parameter.
ALTER STAGE my_ext_stage SET URL='s3://loading/files/new/' COPY_OPTIONS = (ON_ERROR='skip_file');
Alter my_ext_stage
to replace the supplied credentials with a reference to a storage integration named myint
:
ALTER STAGE my_ext_stage SET STORAGE_INTEGRATION = myint;
Alter my_ext_stage
to specify a new access key ID and secret access key for the stage:
ALTER STAGE my_ext_stage SET CREDENTIALS=(AWS_KEY_ID='d4c3b2a1' AWS_SECRET_KEY='z9y8x7w6');(the credentials values used in the above example are for illustration purposes only)
Alter my_ext_stage3
to change the encryption type to AWS_SSE_S3
server-side encryption for the stage:
ALTER STAGE my_ext_stage3 SET ENCRYPTION=(TYPE='AWS_SSE_S3');
Directory table examples¶
Add a directory table to an existing stage named mystage
:
ALTER STAGE mystage SET DIRECTORY = ( ENABLE = TRUE );
Manually refresh the directory table metadata in a stage named mystage
:
ALTER STAGE mystage REFRESH;
+-------------------------+----------------+-------------------------------+
| file | status | description |
|-------------------------+----------------+-------------------------------|
| data/json/myfile.json | REGISTERED_NEW | File registered successfully. |
+-------------------------+----------------+-------------------------------+
Manually refresh the directory table metadata for the files in the data
path in a stage named mystage
:
ALTER STAGE mystage REFRESH SUBPATH = 'data';