> For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://help.sigmacomputing.com/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://help.sigmacomputing.com/_mcp/server. # Troubleshoot input table connection issues > Resolve Sigma input table connection errors caused by configuration or data platform issues affecting saves and new tables. When you encounter an input table error (as a general user) or receive a system email notifying you of failed input table edits (as an admin), it can be the result of a configuration or availability issue in your connection or data platform. This type of issue must be resolved by an admin within Sigma or directly in the data platform. This document explains how Sigma handles input table errors resulting from configuration and availability issues and provides guidance on troubleshooting and resolving these errors. ## User requirements The ability to resolve an input table issue identified in this document requires the following: * You must be assigned the **Admin** [account type](/docs/create-and-manage-account-types). * You must have the necessary privileges in the data platform to perform the resolution tasks identified in this document. If you don't meet these requirements, contact your Sigma or data platform administrator to resolve the issue. ## Input table error handling To improve data integrity and prevent unexpected data loss, Sigma handles input table errors as follows: * When an input table edit is unsuccessful due to configuration or availability issues in the connection or data platform, Sigma treats it as a fatal error and does not retry the operation. The underlying issue is not recoverable by Sigma, therefore, retrying the operation would continue to fail. * An input table error resulting from a configuration or availability issue in the connection or data platform can apply to specific users or the entire organization. When Sigma detects this type of issue, it temporarily restricts the ability for affected users to create and edit input tables that are subject to the same error. Following the initial input table error, all relevant existing input table elements display an “Editing restricted” message. * Sigma sends admins an email alert that identifies the misconfigured or unavailable connection, displays the error message, and links to this document. ## Troubleshooting steps Complete the following steps to troubleshoot the error. 1. Review the organization and connection identified in the system email. This is important if you manage multiple organizations or connections. 2. Check the error message identified in the system email. 3. Locate the error message in the [Error messages and resolutions](#error-messages-and-resolutions) tables. If you cannot find the applicable error message, [contact Support](/docs/sigma-support). 4. Review the root cause, then complete the resolution provided for the authentication method configured on your connection. ## Error messages and resolutions This section provides details about known configuration and availability errors specific to BigQuery, Databricks, PostgreSQL, Redshift, and Snowflake. If you encounter an error message that's not included in the following tables, [contact Support](/docs/sigma-support). #### Incorrect WAL schema | | | | :------------ | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Error message | `wrong schema for WAL table ..` | | Root cause |

The edit cannot be logged and committed due to a non-compliant write-ahead log (WAL) schema.

Possible causes: A user modified the schema in BigQuery by making one or more changes to a column or constraint.

| | Resolution |

Compare the schema of the existing table against the `CREATE TABLE` statement below. If the schema doesn't match the exact column names, data types, and constraints provided in the SQL definition, correct the discrepancy.

If the schema cannot be corrected, delete it and run the SQL to create a compliant table.

CREATE TABLE IF NOT EXISTS \<project>.\<dataset>.SIGDS\_WAL\_\<connection\_id> (
  DS\_ID BYTES NOT NULL,
  EDIT\_ID BYTES NOT NULL,
  USER\_ID BYTES NOT NULL,
  EDIT\_NUM INT64 NOT NULL,
  PROTOCOL\_VERSION INT64 NOT NULL,
  EDIT JSON NOT NULL,
  METADATA STRING NOT NULL,
  TIMESTAMP TIMESTAMP NOT NULL
)
| #### Insufficient privileges | | | | :------------ | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Error message | `execution error: failed to execute query: unexpected operation state ERROR_STATE: [INSUFFICIENT_PERMISSIONS] Insufficient privileges: User does not have on . SQLSTATE: 42501` | | Root cause | The service principal doesn't have the privilege required to perform the identified operation | | Resolution |

Refer to Show, grant, and revoke privileges in the Databricks documentation to ensure that the service principal used for your connection is granted the required catalog and schema privileges.

For information about the required privileges, see [Configure Databricks](/docs/connect-to-databricks#configure-databricks).

| #### Invalid or expired access token | | | | :--------------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Error message |

Databricks access token is invalid or expired.

or

Invalid Databricks access token. | | Root cause |

The access token provided in the connection configuration could not be used for authentication.

Possible causes:

  • The token provided contains a typo.
  • An incorrect token was provided.
  • The token has been deleted or revoked.
  • The token has expired.
| | Resolution (non-OAuth) |

In Sigma, go to the connection configuration page and enter a valid token in the Connection Credentials > Access token field.

If the access token has expired or been deleted or revoked, refer to Databricks personal access tokens for workspace users in the Databricks documentation to generate a new one.

For more information about access token requirements, see [Specify your connection credentials](/docs/connect-to-databricks#specify-your-connection-credentials) .

| | Resolution (OAuth) |

In Sigma, go to the connection configuration page and enter a valid token in the Service Account Configuration > Access token field.

If the access token has expired or been deleted or revoked, refer to Databricks personal access tokens for service principals in the Databricks documentation to generate a new one.

For more information about access token requirements, see [Configure OAuth features](/docs/connect-to-databricks#configure-oauth-features).

| #### Incorrect WAL schema | | | | :------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | Error message | `wrong schema for WAL table ..` | | Root cause |

The edit cannot be logged and committed due to a non-compliant write-ahead log (WAL) schema.

Possible causes: A user modified the schema in Databricks by making one or more changes to a column or constraint.

| | Resolution |

Compare the schema of the existing table against the `CREATE TABLE` statement below. If the schema doesn't match the exact column names, data types, constraints, comments, and partitioning provided in the SQL definition, correct the discrepancy.

If the schema cannot be corrected, delete it and run the SQL to create a compliant table.

CREATE TABLE IF NOT EXISTS \<catalog>.\<schema>.SIGDS\_WAL\_\<connection\_id> (
  DS\_ID STRING NOT NULL COMMENT "SIGMA\_INPUTTABLE\_KEYFIELD\_NOT\_NULL",
  EDIT\_ID BINARY NOT NULL COMMENT "SIGMA\_INPUTTABLE\_KEYFIELD\_NOT\_NULL",
  USER\_ID BINARY NOT NULL COMMENT "SIGMA\_INPUTTABLE\_KEYFIELD\_NOT\_NULL",
  EDIT\_NUM BIGINT NOT NULL COMMENT "SIGMA\_INPUTTABLE\_KEYFIELD\_NOT\_NULL",
  PROTOCOL\_VERSION BIGINT NOT NULL COMMENT "SIGMA\_INPUTTABLE\_KEYFIELD\_NOT\_NULL",
  EDIT STRING NOT NULL COMMENT "SIGMA\_INPUTTABLE\_KEYFIELD\_NOT\_NULL",
  METADATA STRING NOT NULL COMMENT "SIGMA\_INPUTTABLE\_KEYFIELD\_NOT\_NULL",
  TIMESTAMP TIMESTAMP NOT NULL COMMENT "SIGMA\_INPUTTABLE\_KEYFIELD\_NOT\_NULL"
) PARTITIONED BY(DS\_ID)
| #### Incorrect WAL schema | | | | :------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Error message | `wrong schema for WAL table ..` | | Root cause |

The edit cannot be logged and committed due to a non-compliant write-ahead log (WAL) schema.

Possible causes: A user modified the schema in PostgreSQL by making one or more changes to a column or constraint.

| | Resolution |

Compare the schema of the existing table against the `CREATE TABLE` statement below. If the schema doesn't match the exact column names, data types, and constraints provided in the SQL definition, correct the discrepancy.

If the schema cannot be corrected, delete it and run the SQL to create a compliant table.

CREATE TABLE IF NOT EXISTS \<schema>.SIGDS\_WAL\_\<connection\_id> (
  DS\_ID BYTEA NOT NULL,
  EDIT\_ID BYTEA NOT NULL,
  USER\_ID BYTEA NOT NULL,
  EDIT\_NUM BIGINT NOT NULL,
  PROTOCOL\_VERSION SMALLINT NOT NULL,
  EDIT JSON NOT NULL,
  METADATA JSON NOT NULL,
  TIMESTAMP TIMESTAMPTZ NOT NULL,
  PRIMARY KEY (DS\_ID, EDIT\_ID),
  UNIQUE (DS\_ID, EDIT\_NUM)
);
| #### Case sensitivity enabled | | | | :------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Error message | `enable_case_sensitive_identifier must be off` | | Root cause | The `enable_case_sensitive_identifier` configuration value in Redshift is set to `true`, causing input table edits to fail. | | Resolution |

In Redshift, set the `enable_case_sensitive_identifier` to `false`.

For more information about the configuration value, see enable\_case\_sensitive\_identifier in the Redshift documentation.

| #### Incorrect WAL schema | | | | :------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Error message | `wrong schema for WAL table ..` | | Root cause |

The edit cannot be logged and committed due to a non-compliant write-ahead log (WAL) schema.

Possible causes: A user modified the schema in Redshift by making one or more changes to a column or constraint.

| | Resolution |

Compare the schema of the existing table against the `CREATE TABLE` statement below. If the schema doesn't match the exact column names, data types, and constraints provided in the SQL definition, correct the discrepancy.

If the schema cannot be corrected, delete it and run the SQL to create a compliant table.

CREATE TABLE IF NOT EXISTS \<schema>.SIGDS\_WAL\_\<connection\_id> (
  DS\_ID VARBINARY(16) NOT NULL,
  EDIT\_ID VARBINARY(16) NOT NULL,
  USER\_ID VARBINARY NOT NULL,
  EDIT\_NUM BIGINT NOT NULL,
  PROTOCOL\_VERSION SMALLINT NOT NULL,
  EDIT SUPER NOT NULL,
  METADATA SUPER NOT NULL,
  TIMESTAMP TIMESTAMPTZ NOT NULL
) SORTKEY (DS\_ID, EDIT\_ID)
| #### Role not found | | | | :--------------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Error message | `Role does not exist` | | Root cause |

The role provided in the connection configuration cannot be found in your Snowflake environment.

Possible causes:

  • The role provided contains a typo or case sensitivity issue.
  • The role was deleted in Snowflake.
| | Resolution (non-OAuth) |

In Sigma, go to the connection configuration page and verify that the role name is entered correctly in the **Connection Credentials** > **Role** field.

If the role was deleted, refer to Create a role in the Snowflake documentation to recreate it (you cannot recover a deleted role).

For more information about setting a role in the connection configuration, see [Connect to Snowflake with key pair authentication](/docs/connect-to-snowflake#connect-to-snowflake-with-key-pair-authentication) or [Connect to Snowflake with basic authentication](/docs/connect-to-snowflake#connect-to-snowflake-with-basic-authentication).

| | Resolution (OAuth) |

In Sigma, go to the connection configuration page and verify that the role name is entered correctly in the **Service Account Configuration** > **Role** field.

If the role was deleted, refer to Create a role in the Snowflake documentation to recreate it (you cannot recover a deleted role).

For more information about setting a role in the connection configuration, see [Connect to Snowflake with OAuth](/docs/connect-to-snowflake#connect-to-snowflake-with-oauth).

| #### Cannot access warehouse | | | | :--------------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Error message |

000606 (57P03): No active warehouse selected in the current session. Select an active warehouse with the 'use warehouse' command.

| | Root cause |

The connection cannot access a warehouse.

Possible cause: The warehouse is set using a user attribute that's invalid or has no value assigned to the user.

| | Resolution (non-OAuth) |

In Sigma, go to the connection configuration page and verify that the user attribute name used to set the warehouse is entered correctly in the **Connection Credentials** > **Warehouse** field.

If the user attribute name provided is valid, see [Configure user attributes on a Snowflake connection](/docs/dynamically-assign-roles-used-by-a-connection) to ensure that the user is assigned a warehouse attribute.

| | Resolution (OAuth) |

In Sigma, go to the connection configuration page and verify that the user attribute name used to set the warehouse is entered correctly in the **Connection Credentials** > **Warehouse** field.

If the user attribute name provided is valid, see [Configure user attributes on a Snowflake connection](/docs/dynamically-assign-roles-used-by-a-connection) to ensure that the user is assigned a warehouse attribute.

| #### Cannot access tables | | | | :------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | Error message | `002003 (42S02): SQL compilation error: Object does not exist or not authorized.` | | Root cause |

The connection cannot access tables containing input table data and the edit log.

Possible causes:

  • The role provided doesn't have the Snowflake privileges required to access the identified table.
  • The table was deleted or moved.
| | Resolution | See [Restore input table access for a Snowflake connection or user](/docs/restore-input-table-access-for-a-snowflake-connection-or-user). | #### Insufficient role privileges | | | | :------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | Error message | `003001 (42501): SQL access control error: Insufficient privileges to operate on schema ` | | Root cause | The role provided in the connection configuration doesn't have the Snowflake privileges required to perform the operation on the identified schema. | | Resolution |

Refer to Grant privileges to a role in the Snowflake documentation to grant the required privileges to the role.

For more information about the schema privileges required to correctly configure write access, see [Configure write access](/docs/connect-to-snowflake#configure-write-access).

| #### User access disabled | | | | :--------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Error message |

390101 (08004): User access disabled. Contact your local system administrator.

| | Root cause |

The username and password provided in the connection configuration has been changed or disabled.

| | Resolution (non-OAuth) |

In Sigma, go to the connection configuration page and update the **User** and **Password** fields (or **User**, **Private key**, and **Private key passphrase** if the connection uses key pair authentication) in the **Connection Credentials** section.

Alternatively, refer to Disabling or enabling a user in the Snowflake documentation to re-enable the user.

| #### Incorrect WAL schema | | | | :------------ | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Error message | `wrong schema for WAL table ..` | | Root cause |

The edit cannot be logged and committed due to a non-compliant write-ahead log (WAL) schema.

Possible causes: A user modified the schema in Snowflake by making one or more changes to a column or constraint.

| | Resolution |

Compare the schema of the existing table against the `CREATE TABLE` statement below. If the schema doesn't match the exact column names, data types, and constraints provided in the SQL definition, correct the discrepancy.

If the schema cannot be corrected, delete it and run the SQL to create a compliant table.

CREATE TABLE IF NOT EXISTS \<CATALOG>.\<SCHEMA>.SIGDS\_WAL\_\<connection\_id> (
  DS\_ID BINARY(16) NOT NULL,
  EDIT\_ID BINARY(16) NOT NULL,
  USER\_ID BINARY(36) NOT NULL,
  EDIT\_NUM BIGINT NOT NULL,
  PROTOCOL\_VERSION SMALLINT NOT NULL,
  EDIT TEXT NOT NULL,
  METADATA TEXT NOT NULL,
  TIMESTAMP TIMESTAMP\_NTZ NOT NULL
) CLUSTER BY (DS\_ID)
|