Glossary

16min
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This page lists terms used in the Looker product and user documentation.
A
Admins have a variety of options for limiting what users can view and interact with in Looker.
A data action lets users perform tasks in other tools, directly from Looker. For example, the action can cause an email to be sent or can set values in other applications — or it can do anything else that you can configure a receiving server to do. The receiving server must be able to accept a JSON POST.
An advanced filter lets users create a dashboard filter with a field from an Explore that is not represented on the dashboard itself.
Alerts enable users to specify conditions in the data of a dashboard tile that, when met or exceeded, trigger a notification to be sent at the desired frequency to specific recipients. Alerts are set on query-based or Look-linked tiles on user-defined dashboards, LookML dashboards, and legacy dashboards; and they can be sent through email or with Looker's Slack or Slack Attachment (API Token) integrations.
Application Time Zone is an admin setting for the default time zone in which scheduled Looks and queries run, where supported. When User Specific Time Zones are enabled, the Application Time Zone becomes the default time zone for users who do not have a time zone value set for their accounts.
An asynchronous (or async) query is a data request that makes one call to start the request, one or more calls to check the completion status of the query, and one call to fetch the results of the completed query. Async queries can help avoid freezing apps, connection timeouts and long dashboard load times.
B
A base view is the view used as the starting point for building an Explore. From there, you can join other views into the base view to be used in the Explore. Typically, Explores are named after the base view, but you can also use the from parameter to name the Explore's base view if you don't want to name the Explore after its base view.
Looker Blocks are pre-built pieces of LookML that you can use and customize to your exact specification. From optimized SQL patterns to fully built-out data models, blocks can be used as a starting point for quick and flexible data modeling in Looker.
A board holds a collection of manually curated dashboards, Looks, and links. Dashboards and Looks, which are stored in folders, can be pinned to multiple boards. Boards may include links and descriptions to provide context and can make it easier for users to find the information that is most relevant to them.
Browsing involves viewing, sharing, sending, and downloading data from dashboards, Looks, and Explores.
C
Formerly known as Discourse, the Looker Community is a user forum featuring posts, discussions, questions, and ideas shared among Looker users and experts.
Looker components are the technical implementation of the Looker Design System, built with React, TypeScript, and Styled Components. They consist of UI components, filter components, and visualization components.
In the Admin section of Looker, you establish the database connection from which a model will retrieve data.
Constants, which are defined with the LookML constant parameter in a project manifest file, let you specify a value that can be reused throughout a project. You can reference constants anywhere in your model where strings are accepted.
In Looker's documentation, the term content typically refers to Looks and dashboards.
Content access controls whether a user or group can view or make changes to a board, or to a folder (called a Space prior to Looker 6.20) and its contents. The two content access levels are View and Manage Access, Edit.
Cross-filtering lets users apply ad hoc filters to dashboards that use the new dashboard experience. With cross-filtering, users can click a data point in one dashboard tile to have all dashboard tiles automatically filter on that value. Specific cross-filters cannot be saved to a dashboard, but they can be shared by sharing a cross-filtered dashboard's URL.
D
A dashboard is essentially a collection of one or more saved queries, displayed as visualization or text tiles together on one page. Looker offers two types of dashboard experience: new dashboards and legacy dashboards. 
Data access controls which data a user or group is allowed to view. This type of access can be restricted or granted either at the user level or at the data level.
A dimension is a field that represents an attribute, fact, or value, which can be selected from the field picker within an Explore and can be used to filter a query. Common dimensions include such attributes as dates, names, and IDs, and often correspond to columns in your underlying data table. A dimension can also be created within a view file.
Dimension fill is a feature that lets you instruct Looker to fill in missing dates or values for a given dimension, such as a date dimension with some years missing. You can avoid misleading graphs by preventing Looker from connecting the values in an incomplete set. The dimension fill option can be turned on or off with the allow_fill parameter.
Using a dimension group, you can create multiple dimensions for a single underlying date or time column in the database. For example, you could split a duration-type dimension group into intervals of days, weeks, months, and so on.
Looker makes it possible to drill into the data on a visualization or an Explore to get more specific information about a specific data point. To drill into data on a visualization, select the part of the visualization about which you'd like more information. For the Data section of an Explore, select the value of a measure, or select the value of a dimension that can be drilled into.
E
An element is a tile or visualization on a LookML dashboard, created using the element parameter
Explore (n.)
An Explore is the starting point for queries. An Explore shows a specified set of fields from its associated view file, and these fields can be selected from the field picker to construct a query, which can be saved as a Look or dashboard tile. Explore URLs can also be shared.
explore, exploring (v.)
Exploring involves using data to answer questions in Looker.
An Explore file is a LookML project file with the extension .explore.lkml. Can be used for extending Explores across models and for defining native derived tables.
The explore parameter adds a view to Looker's menu of Explores. As a best practice, an Explore should be defined inside of a model file. Explores reference views and each Explore can contain joins to other views. An Explore can also be defined in an Explore file that is then included in a model file.
Extensions are web applications built with Looker components that are developed through the Looker extension framework. 
F
A fanout occurs when one row of a primary data table can correspond to more than one row of a joined table, resulting in duplicated records and incorrectly calculated aggregations. In Looker, the fanout problem is avoided through the use of symmetric aggregates and by correctly defining the dataset's primary key.
Feature access controls the types of actions a user is allowed to take in Looker. This type of access is managed by permission sets.
Explores and views contain fields, mostly dimensions and measures, which are the fundamental building blocks for Looker queries.
Filter expressions are an advanced way to filter Looker queries. You can use them in the Explore section of Looker by adding a filter and choosing the matches (advanced) option. They are also used in LookML for elements that take a filter parameter. You can write filter expressions to filter on a string or to partially match strings, date and time, Boolean values, numbers, and location fields.
In the Looker UI, a folder is a place where dashboards, Looks, and other folders (subfolders) are stored. Each user has a personal folder, and a Looker instance can also have various kinds of shared folders. Access to content in Looker is allocated at the folder level. Folders were called "Spaces" prior to Looker 6.20.
In the Looker IDE, a folder is an organizational structure for your LookML files.
Looker functions let you transform your data or reference data in complex ways. They are similar in nature to Excel functions.
G
Users can be added to one or more groups. Groups are useful for managing users' access to particular data, features, and content within Looker, as well as for assigning roles to users in bulk.
J
(n.) The join parameter lets you define the join relationship between an Explore and a view, so that you can combine data from multiple views. You can join in as many views as you like for any given Explore.
(v.) Combine data from multiple views by defining the relationship between an Explore and a view through a join parameter.
L
Look is a single table or visualization saved as its own individual report. Looks can be added to dashboards, scheduled, shared, and made public. Any changes made to a Look will be reflected in any dashboards that contain it.
Table calculations, custom fields, and custom filters rely on Looker expressions (Lexp) to perform calculations. A Looker expression is built from a combination of functions, operators, and fields, and possibly constants or variables
LookML is a language for describing dimensions, aggregates, calculations and data relationships in a SQL database. The Looker app uses a model written in LookML to construct SQL queries against a particular database
A LookML dashboard is written entirely using LookML (as opposed to a user-defined dashboard, which is created by using the visualization editor).
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M
A measure is a field in an Explore that represents measurable information about your data, such as sums, counts, and so forth. A measure is declared in a view file and can be of an aggregate or non-aggregate type
The Merged Results feature lets you combine data from different Explores (even from different models, projects, or connections). Using the Merged Results feature, you can create a query from an Explore, then add queries from other Explores to display the merged results in a single table. The Merged Results feature performs similarly to a left join in SQL: it's as if the added query is being left-joined into the primary query
The metadata panel in the Looker IDE shows contextually relevant information for a LookML object. For example, if your cursor is on a view parameter in the IDE, the metadata panel will show you which Explores have that view joined in and other views that are extensions of that view.
P
Admins can manage permissions to determine which users and groups can access content, data, and features. Permissions can be model-specific or instance-wide. Permission sets must be used as part of a role to have any effect
The primary key is the dimension that has exactly one unique value for each row of data. When data tables are joined together in a one-to-many relationship, the primary key must be defined correctly in order to avoid a fanout
A primary query is a single query created from a single Explore. When working with merged results, the primary query is a similar concept to the primary ID when joining multiple tables in SQL
In Looker, a project is a set of related models and other files (like Explores, views, and LookML dashboards) that you will use to define your data model. In general, a project corresponds to a single Git repository.
R
A role defines the privileges that a user or group will have for a specific set of models in Looker. Create a role by combining one model set with one permission set.
S
A Space is a folder where dashboards, Looks, and other Spaces (subspaces) are stored. Each user has a personal Space, and a Looker instance can also have a variety of shared Spaces. Access to content in Looker is allocated at the Space level. Spaces are also known as folders
A SQL-based derived table is a derived table that has a query defined with a SQL query, referring to columns in your database. SQL-based derived tables can be temporary or persistent.
T
Table calculations are similar to spreadsheet formulas and are performed on the results of a query, after the query has executed
Themes are a way to customize the appearance of your embedded Looker dashboards and Explores. You can use themes to customize font family, text color, background color, tile color, and other visual elements
Tiles are visualizations that are added to a dashboard from an Explore or a Look. Tiles can be query-based or Look-linked. Query tiles differ from Look-linked tiles because they are stored only on dashboards.
U
By unsubscribing, users can choose to stop receiving scheduled content deliveries and alert notifications. The consequences for unsubscribing differ depending on how the delivery is set up
User Specific Time Zones is an admin option that, when enabled, lets users choose their own time zones. Queries will be created with the time zones of the users who created them
User-defined dashboards are created by adding content through Looker's user interface, rather than using LookML. This is the most common type of dashboard.
V
In Looker, a view can represent an underlying database table or a derived table. Views are the building blocks for Explores, which make the information in a view available for querying with the field picker in the Explore UI. By convention, a view is defined in a view file.
A view file is where you define the dimensions, measures, and other fields that are used in your LookML model.
Visual drilling is supported by dashboards using the new dashboard experience. To enable visual drilling, LookML developers customize a drill visualization using the link parameter. Dashboard viewers can select whether to view the custom visualization or a data table by clicking buttons at the top of the drill window.
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Updated 09 Jul 2024
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