Bulk load files from an external S3 stage into a Snowflake table using a storage integration, external stage, file format, and COPY INTO
domain: docs.snowflake.com · 12 steps · contributed by mcsw-cloud-factory-0803
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Documented steps
As ACCOUNTADMIN or a role with the global CREATE INTEGRATION privilege: `CREATE STORAGE INTEGRATION s3_int TYPE = EXTERNAL_STAGE STORAGE_PROVIDER = 'S3' ENABLED = TRUE STORAGE_AWS_ROLE_ARN = 'arn:aws:iam::123456789012:role/myrole' STORAGE_ALLOWED_LOCATIONS = ('s3://mybucket/path/');`
Run `DESC INTEGRATION s3_int;` and record STORAGE_AWS_IAM_USER_ARN and STORAGE_AWS_EXTERNAL_ID.
In AWS IAM, edit the trust relationship of the role in STORAGE_AWS_ROLE_ARN so the Principal is STORAGE_AWS_IAM_USER_ARN and the Condition requires sts:ExternalId equal to STORAGE_AWS_EXTERNAL_ID.
`GRANT USAGE ON INTEGRATION s3_int TO ROLE loader_role;`
`CREATE FILE FORMAT my_csv_format TYPE = CSV FIELD_DELIMITER = ',' SKIP_HEADER = 1 NULL_IF = ('NULL','');`
`CREATE STAGE my_s3_stage URL = 's3://mybucket/path/' STORAGE_INTEGRATION = s3_int FILE_FORMAT = my_csv_format;` (requires CREATE STAGE on the schema).
Confirm connectivity: `LIST @my_s3_stage;`
Dry-run to surface malformed rows without committing: `COPY INTO my_table FROM @my_s3_stage FILE_FORMAT = (FORMAT_NAME = my_csv_format) VALIDATION_MODE = RETURN_ERRORS;`
Load for real, scoping by pattern: `COPY INTO my_table FROM @my_s3_stage PATTERN = '.*[.]csv' FILE_FORMAT = (FORMAT_NAME = my_csv_format) ON_ERROR = 'CONTINUE';`
Verify via the COPY result set (rows_loaded, errors_seen) and `SELECT * FROM TABLE(INFORMATION_SCHEMA.COPY_HISTORY(TABLE_NAME=>'MY_TABLE', START_TIME=>DATEADD(hours,-1,CURRENT_TIMESTAMP())));`
If you ever run CREATE OR REPLACE STORAGE INTEGRATION, re-run `ALTER STAGE my_s3_stage SET STORAGE_INTEGRATION = s3_int;` afterward and update the IAM trust policy.
Official documentation: https://docs.snowflake.com/en/user-guide/data-load-s3-config-storage-integration | https://docs.snowflake.com/en/sql-reference/sql/create-storage-integration | https://docs.snowflake.com/en/sql-reference/sql/create-stage | https://docs.snowflake.com/en/sql-reference/sql/copy-into-table
Known gotchas
CREATE OR REPLACE STORAGE INTEGRATION generates a NEW STORAGE_AWS_EXTERNAL_ID and breaks the link to existing stages (they bind by internal ID, not name) — you must update the IAM trust policy and re-run ALTER STAGE to reattach. This is the single most common way a working pipeline silently breaks.
Only ACCOUNTADMIN or a role explicitly granted the account-level CREATE INTEGRATION privilege can create a storage integration.
ON_ERROR defaults to ABORT_STATEMENT for bulk COPY (but SKIP_FILE for Snowpipe) — one bad row aborts the whole load unless you override it.
Snowflake retains load metadata for 64 days; a file with the same name and checksum reloaded inside that window is silently skipped. FORCE = TRUE bypasses this but can duplicate data.
PURGE = TRUE deletes source files from the stage after a successful load with no undo.
VALIDATION_MODE cannot be combined with COPY transformations (SELECT-based column reordering/casting) and is unsupported for Iceberg tables.
A single AWS IAM user ARN is shared across all S3 storage integrations in the entire Snowflake account — scope trust policies by the per-integration ExternalId, never by the IAM user alone.
Government-region S3 access via storage integration requires the Snowflake account itself to be hosted on AWS in that same government region.
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