Function cckMetadataPathForOrdinary

src/Databases/DatabaseFactory.cpp:37–73

}

static void cckMetadataPathForOrdinary(const ASTCreateQuery & create, const String & metadata_path)
{
    auto default_db_disk = Context::getGlobalContextInstance()->getDatabaseDisk();

    if (!default_db_disk->isSymlinkSupported())
        return;

    const String & engine_name = create.storage->engine->name;
    const String & database_name = create.getDatabase();

    if (engine_name != "Ordinary")
        return;

    if (!default_db_disk->isSymlink(metadata_path))
        return;

    String target_path = default_db_disk->readSymlink(metadata_path);
    fs::path path_to_remove = metadata_path;
    if (path_to_remove.filename().empty())
        path_to_remove = path_to_remove.parent_path();

    /// Before 20.7 metadata/db_name.sql file might absent and Ordinary database was attached if there's metadata/db_name/ dir.
    /// Between 20.7 and 22.7 metadata/db_name.sql was created in this case as well.
    /// Since 20.7 `default` database is created with Atomic engine on the very first server run.
    /// The problem is that if server crashed during the very first run and metadata/db_name/ -> store/whatever symlink was created
    /// then it's considered as Ordinary database. And it even works somehow
    /// until background task tries to remove unused dir from store/...
    throw Exception(ErrorCodes::CANNOT_CREATE_DATABASE,
                    "Metadata directory {} for Ordinary database {} is a symbolic link to {}. "
                    "It may be a result of manual intervention, crash on very first server start or a bug. "
                    "Database cannot be attached (it's kind of protection from potential data loss). "
                    "Metadata directory must not be a symlink and must contain tables metadata files itself. "
                    "You have to resolve this manually. It can be done like this: rm {}; sudo -u clickhouse mv {} {};",
                    metadata_path, database_name, target_path,
                    quoteString(path_to_remove.string()), quoteString(target_path), quoteString(path_to_remove.string()));

}

void DatabaseFactory::validate(const ASTCreateQuery & create_query) const
{