getredash/redash · error · Exception

Failed getting schema.

Error message

Failed getting schema.

What it means

Raised by Sqlite._get_tables (redash/query_runner/sqlite.py:40) when querying sqlite_master for the table list returns a non-None error. It fires while building the schema for the schema browser; the underlying run_query failure (unreadable/corrupt database file, locked database, permissions) is the actual cause but is discarded.

Source

Thrown at redash/query_runner/sqlite.py:40

        }

    @classmethod
    def type(cls):
        return "sqlite"

    def __init__(self, configuration):
        super(Sqlite, self).__init__(configuration)

        self._dbpath = self.configuration.get("dbpath", "")

    def _get_tables(self, schema):
        query_table = "select tbl_name from sqlite_master where type='table'"
        query_columns = 'PRAGMA table_info("%s")'

        results, error = self.run_query(query_table, None)

        if error is not None:
            raise Exception("Failed getting schema.")

        for row in results["rows"]:
            table_name = row["tbl_name"]
            schema[table_name] = {"name": table_name, "columns": []}
            results_table, error = self.run_query(query_columns % (table_name,), None)
            if error is not None:
                self._handle_run_query_error(error)

            for row_column in results_table["rows"]:
                schema[table_name]["columns"].append(row_column["name"])

        return list(schema.values())

    def run_query(self, query, user):
        connection = sqlite3.connect(self._dbpath)

        cursor = connection.cursor()

View on GitHub (pinned to ca79fe988d)

Solutions

1. Verify the database path is absolute and readable by the Redash worker user (test with `ls -l` and `sqlite3 <db> '.tables'` inside the worker container)
2. If the file is locked, stop the writing process or enable WAL / busy_timeout on the writer
3. If the file is corrupt or empty, restore from a backup or recreate it before refreshing the schema

import os, sqlite3
if not os.path.isfile(db_path) or not os.access(db_path, os.R_OK):
    raise ValueError('sqlite db missing/unreadable: {}'.format(db_path))
conn = sqlite3.connect(db_path); conn.close()

try:
    tables = ds.query_runner.get_schema()
except Exception as e:
    logger.warning('sqlite schema failed: %s', e)
    tables = []

When it happens

Trigger: Opening the schema dialog for a SQLite data source whose file path is unreadable, is locked by another writer, or is not a valid SQLite database; also when the configured file lives on a path the Redash worker cannot access.

Common situations: Wrong file path in the data source config (relative vs absolute); database file on a mount not visible to the worker container; file created by a newer/incompatible SQLite page format or corrupt; concurrent writer holding an exclusive lock.

Related errors

• Error during query execution. Reason: {error}
• Failed to get schema: {str(e)}
• Failed to get tables: {error}
• Error creating table {}: {}
• Failed getting schema

AI-assisted analysis of getredash/redash@ca79fe988d (2026-08-28). Data as JSON: /api/errors/54ee7f709f660e1b. Report an issue: GitHub.