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Differences between the 2.x and 1.x versions of the ODBC driver - Amazon Redshift
Key differences to addressConnection string and DSN optionsData type changesPost-migration troubleshootingUpgrading from an older ODBC 2.x versionMore information

Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the blog post .

Differences between the 2.x and 1.x versions of the ODBC driver

This section describes the differences between the ODBC 1.x driver and the ODBC 2.x driver, and provides guidance about how to migrate to the 2.x driver. It describes the changes that might affect your application and how to address them.

Key differences to address

The following actions resolve the most common migration issues. Most applications need only a subset of these.

DSN and connection string

  • Review your DSN for driver options that might have been removed or renamed. Some ODBC 1.x driver options are not supported in the ODBC 2.x driver. Others have been renamed. See Connection string and DSN options for details.

  • Set UseUnicode=true if your application depends on wide character type codes (SQL_WVARCHAR, SQL_WCHAR). In the ODBC 2.x driver, UseUnicode defaults to false, which reports narrow character types.

  • Move logging settings to the [ODBC] section. On Linux and macOS, LogLevel and LogPath must be set in the global [ODBC] section of odbc.ini, not in an individual DSN section.

Query and schema

  • Include EXTERNAL TABLE in SQLTables type filters. In ODBC 2.x, both Amazon Redshift Spectrum tables and datashare tables are reported as EXTERNAL TABLE. If you filter SQLTables by type, add EXTERNAL TABLE to keep seeing these objects.

  • Cast INTERVAL to VARCHAR for applications that do not support the interval data type. Some clients do not support ODBC interval types. For those clients, cast the column in your query: SELECT col::VARCHAR FROM ...

Application code

  • Verify query timeout settings. ODBC 2.x correctly enforces SQL_ATTR_QUERY_TIMEOUT per the ODBC specification. ODBC 1.x silently ignored this setting. Long-running queries that previously succeeded might now fail with a timeout error. Review and adjust your timeout values as needed.

  • Provide the data length for data-at-execution parameters. 2.x reports SQL_NEED_LONG_DATA_LEN as Y (1.x reported N). Applications that bind SQL_DATA_AT_EXEC parameters must now supply the total data length up front in StrLen_or_IndPtr.

Connection string and DSN options

The following table shows ODBC 1.x driver options that have either been renamed or have direct equivalents in the ODBC 2.x driver.

1.x option 2.x equivalent Notes
MaxLongVarChar MaxLongVarcharSize Default changed from 8190 to 65535.
ConnectionTimeout LoginTimeout Same connection timeout, renamed. Defaults to 0 (no timeout).
VpcEndpointUrl vpc_endpoint_url
SSLCertPath TrustStore or CaFile Path to a CA certificate used to verify the server. On Windows, set this in the Trust Store field of the DSN setup dialog; the dialog has no CaFile field. If both are set, TrustStore takes priority.

The following 1.x options are not supported in the current 2.x driver. The 2.x driver ignores them, so they do not affect your connection. Removing them from your DSN is optional but recommended to avoid confusion.

  • SingleRowMode – to limit client memory, use StreamingCursorRows instead.

  • UseSystemTrustStore – not supported. On Windows, the 1.x driver could validate the server certificate against the Windows system certificate store. The 2.x driver validates against a CA certificate file: it uses the bundled Amazon Redshift root certificate by default, or the file you specify in TrustStore or CaFile.

  • BoolsAsChar – if your application relied on BOOLEAN columns being returned as "0" and "1" strings (SQL_VARCHAR), cast the column to VARCHAR in your query, for example SELECT col::VARCHAR FROM ....

  • TextAsLongVarchar, CheckCertRevocation, EnableAwsSdkLogs, UseLogPrefix, Locale, UseDeclareFetch, UseMultipleStatements, EnforceSingleStatement, EnableTableTypes – no equivalent in the current release. The Amazon Redshift team is evaluating equivalents or alternatives for these options in future releases.

For the full list of supported 2.x options, see ODBC driver options.

Data type changes

The following table shows Amazon Redshift data type mappings that changed in ODBC 2.x to comply with the ODBC specification. Most applications are unaffected because they bind columns by index or by name rather than by type code.

Amazon Redshift data type ODBC 1.x ODBC 2.x
DOUBLE PRECISION SQL_FLOAT (6) SQL_DOUBLE (8)
INTERVAL YEAR TO MONTH SQL_VARCHAR (12), text SQL_INTERVAL_YEAR_TO_MONTH (107), interval struct
INTERVAL DAY TO SECOND SQL_VARCHAR (12), text SQL_INTERVAL_DAY_TO_SECOND (110), interval struct
VARCHAR / CHAR / TEXT Wide types (SQL_WVARCHAR, SQL_WCHAR, SQL_WLONGVARCHAR); default UseUnicode=true Narrow types (SQL_VARCHAR, SQL_CHAR, SQL_LONGVARCHAR). Set UseUnicode=true to restore wide types.
GEOMETRY / GEOGRAPHY (as SQL_C_BINARY) Hex-encoded ASCII string Raw binary bytes

The COLUMN_SIZE values returned by SQLColumns also changed for GEOMETRY, GEOGRAPHY, and SUPER data types, which now return NULL to indicate unsized columns per the ODBC specification. Applications that allocate buffers based on COLUMN_SIZE must handle NULL by using a default buffer size.

Post-migration troubleshooting

The following table describes common issues you might encounter after migrating and how to resolve them.

Symptom Cause What to do
External tables not visible in schema browser Spectrum and datashare tables are reported as EXTERNAL TABLE Include EXTERNAL TABLE in SQLTables type filter.
pyodbc errors on interval columns pyodbc does not support ODBC interval types Cast intervals to VARCHAR in queries.
Character data displays as unexpected characters (mojibake) UseUnicode default changed to false. Applications expecting wide-character (UTF-16) data might misinterpret narrow-character bytes as wide pairs, producing garbled output. The data itself is unchanged. Set UseUnicode=true in your DSN, or update your application to bind columns as SQL_C_CHAR instead of SQL_C_WCHAR.
Long-running queries return timeout errors SQL_ATTR_QUERY_TIMEOUT is now enforced. ODBC 1.x silently ignored this setting. Increase or remove QueryTimeout from your DSN, or set SQL_ATTR_QUERY_TIMEOUT to 0 in your application.
Setting SQL_ATTR_CURRENT_CATALOG returns HY011 The attribute cannot be set on an open connection. Switching databases on an open connection is not supported. Set the attribute before connecting, or close and reopen the connection on the target database.
Connection hangs in dual-stack environments Limitation in versions <= 2.1.16 Upgrade to 2.1.17 or later.
Error message parsing returns unexpected results Message format changed; SQLSTATE codes unchanged Parse SQLSTATE codes instead of message text.
Data-at-execution parameter binding behaves differently SQL_NEED_LONG_DATA_LEN changed from FALSE to TRUE; applications using SQL_DATA_AT_EXEC must now provide the total data length up front Set the length value in StrLen_or_IndPtr when binding SQL_DATA_AT_EXEC parameters.
Driver logs are not generated LogLevel and LogPath must be in the [ODBC] global section of odbc.ini, not in individual DSN sections Move logging settings from your DSN to the [ODBC] section.

Upgrading from an older ODBC 2.x version

If you are already running an older ODBC 2.x version, upgrade to the latest release. For a complete list of enhancements and bug fixes across all versions, see the Amazon Redshift ODBC driver change log on GitHub.

More information