What causes 000659 (22001)?

A source system started producing longer strings than the column was designed for. The VARCHAR column length was set too small during table design. A free-text field in the source (comments, notes, descriptions) received an unusually long entry. A data transformation is concatenating strings that can exceed the column length. A Snowpipe or COPY INTO load received data wider than the target column definition

How do I fix 000659 (22001)?

Identify the column and the actual string length: SELECT MAX(LEN(col)) FROM source_data. ALTER TABLE to increase the column length: ALTER TABLE ALTER COLUMN SET DATA TYPE VARCHAR( ). Add a TRUNCATE or LEFT() transformation in the pipeline if the full string is not needed. Validate source data length before loading: add a pre-load check on the source. For Snowpipe loads, check the COPY INTO options for the TRUNCATECOLUMNS parameter as a short-term workaround

Medium severityexecution

Power BI Refresh Error:
000659 (22001)

What does this error mean?

A string value being inserted or loaded into a Snowflake table exceeds the VARCHAR column's defined maximum length. The operation is rejected to preserve data integrity.

Common causes

1A source system started producing longer strings than the column was designed for
2The VARCHAR column length was set too small during table design
3A free-text field in the source (comments, notes, descriptions) received an unusually long entry
4A data transformation is concatenating strings that can exceed the column length
5A Snowpipe or COPY INTO load received data wider than the target column definition

How to fix it

1Identify the column and the actual string length: SELECT MAX(LEN(col)) FROM source_data
2ALTER TABLE to increase the column length: ALTER TABLE <name> ALTER COLUMN <col> SET DATA TYPE VARCHAR(<new_length>)
3Add a TRUNCATE or LEFT() transformation in the pipeline if the full string is not needed
4Validate source data length before loading: add a pre-load check on the source
5For Snowpipe loads, check the COPY INTO options for the TRUNCATECOLUMNS parameter as a short-term workaround

Frequently asked questions

Does Snowflake have a maximum VARCHAR length?

Yes — VARCHAR in Snowflake supports up to 16,777,216 characters (16 MB). For most use cases, VARCHAR(16777216) is effectively unlimited.

Can I use TRUNCATECOLUMNS to avoid this error?

Yes — adding TRUNCATECOLUMNS = TRUE to a COPY INTO statement silently truncates strings that exceed the column length. Use with caution as it silently loses data.