A slot is a unit of CPU time used to execute SQL queries in BigQuery. Depending on query size and complexity, BigQuery allocates between one and eight slots for each query. During the query execution, slots are dynamically re-allocated to accommodate changing resource demands. This process can cause short periods of total slot usage above your specified capacity as jobs borrow additional slots from other queries. Excess slot usage is not billed directly to you and is included in the reported detailed execution statistics.
A reservation with a ignore_idle_slots = false setting can share idle slots with other reservations as long as the reservation is not running a query. Idle slots are allocated using an algorithm called fair scheduling, which is the default for BigQuery. The scheduler balances the need for efficient eviction of running jobs against providing eventual fairness to all projects with running queries.
The term ‘slot’ is also a technical term for the amount of space or memory in a device, such as a hard drive, where files are stored. The term is related to the amount of storage space available in a file system, although there are other types of data storage that do not use slots, such as in flash drives or solid state drives.
Moreover, the word can refer to a position in a game, such as the first defensive lineman or wingman. It can also refer to a specific area of the field, such as the area between the end zone and the blue line in field hockey or ice hockey, or a specific area of the playing field in American football.
A slot can also be a container in a database, where data is stored and used by applications that run on the platform. For example, a site that uses a content distribution network may have multiple slots for different types of media, such as video, audio, and text. This allows users to access the content on a variety of devices and is an important feature for those who want to have flexibility in how they consume their digital media. It is also an essential component for businesses that offer live events, such as webinars and virtual conferences. This is because it provides an opportunity to reach a wider audience by providing the same content across multiple platforms. This can be done without compromising the quality of the experience and increases user engagement. This can result in higher retention and conversion rates, which in turn increase advertising revenues for the business. The company can also offer a subscription model for its content, such as video on demand, which provides an additional revenue stream. This can be beneficial to the company as it does not require upfront payment from its users for each individual video. This can be particularly attractive to customers who do not have the financial means or desire to purchase multiple videos individually.