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This page lists terms used in the Looker product and user documentation.



$ is a substitution operator that lets you reference previously defined objects in LookML.

see also substitution operator


access, access level

Admins have a variety of options for limiting what users can view and interact with in Looker.

see also content access, data access, feature access


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.

Action Hub

Looker’s Action Hub is a multi-tenant service that forwards data to Looker’s integrated services. Any data your users send using an action will be processed temporarily on the Action Hub server rather than in your Looker instance. When your Looker admin or developer has set up an integrated service and a field tag to provide access to that service, you can select that service as an action when you drill into data and interact with that service.

see also action

advanced deploy mode

Advanced deploy mode enables Looker developers with deploy permission to select any Git commit on their LookML project and deploy it to the production version of their Looker instance. This is opposed to the default Git integration, where only the latest commit on the remote production branch can be deployed to the production version of a Looker instance.


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 a 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

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.

see also time zone settings, User Specific Time Zones

asynchronous query

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.


base view (of an Explore)

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.

see also view, Explore

block, Looker Block

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.

browse, browsing

Browsing involves viewing, sharing, sending, and downloading data from dashboards, Looks, and Explores.


closed system

Also called a multitenant installation, a closed system silos content to specific groups and prevents users from different groups from knowing about each other.

code splitting

A technique for lazy loading of JavaScript until it is actually needed. Ideally, you want to keep the initially loaded JavaScript bundle as small as possible. This can be achieved by utilizing code splitting. Any functionality that is not immediately required is not loaded until it is actually needed.


Formerly known as Discourse, the Looker Community is a user forum featuring posts, discussions, questions, and ideas shared among Looker users and experts.


Looker UI components are the technical implementation of the Looker Design System, built with React, TypeScript, and Styled Components.


In the Admin section of Looker, you establish the database connection from which a model will retrieve data.


Constants, defined with the LookML constant parameter in a project manifest file, allow you to 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

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.

Content Validator

Looker’s Content Validator searches your LookML for references to model, Explore, and field names. Developers can use the Content Validator after making changes to a project to check that their changes did not impact any of their users’ saved Looks or query-based dashboard tiles. The Content Validator can also be used to find and replace LookML elements to fix errors due to changes.


Cross-filtering allows users to 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 instead can be shared by sharing a cross-filtered dashboard’s URL.

customer-hosted (deployment, instance, installation)

A “customer-hosted” deployment means that the product is installed by or for the customer at the customer’s premises or on a customer-controlled server within a third-party data center. A customer-hosted deployment includes the in-product services, meaning the services hosted by Looker and accessible through the product, specifically licensing data, configuration backups, system error reports, data actions, and support tickets, as further described in the Application Data Shared by Looker section of Looker’s security webpage. Looker support generally has no access to these instances for support or deployment purposes, and the customer must execute their own version updates.

see also Looker Cloud



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.

see also LookML dashboard, user-defined dashboard

dashboard element, element

An element is a tile or visualization on a LookML dashboard, created using the element parameter.

dashboard file

A LookML dashboard is defined in a LookML project file with the extension .dashboard.lookml.

see also LookML dashboard

data access

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.

Database Time Zone

Database Time Zone is an admin setting for the time zone Looker uses to interpret your raw data.

see also Query Time Zone, time zone settings


You can use one or more datagroup parameters to define a caching policy, to specify when to rebuild persistent derived tables (PDTs), and to trigger schedules.

derived table

Derived tables allow you to create new tables that do not already exist in your database. A derived table is defined in a Looker view file and allows the user to treat the output of a query as if it were a table in the database (typically used for “fact” tables). “Derived table” is a generic term for any type of derived table, including LookML-based (native) derived tables, SQL-based derived tables, temporary derived tables, and persistent derived tables (PDTs).

see also native derived table, persistent derived table, SQL-based derived table, temporary derived table

Development Mode

A developer can enter Development Mode to make and test LookML changes. The changes won’t affect other users until they are deployed to production.

development table

A development table is a persisted derived table that is built when you query the table during development. In some cases, the development table can be used in production when you deploy your changes.


The SQL “flavor” of a database. Examples of supported dialects are Amazon Redshift, PostgreSQL, MySQL, and Google BigQuery Standard SQL or Legacy SQL.


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

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.

dimension group

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.


embed, embedding

Embedding involves using iframe code to place an object (e.g., Looker charts or tables) into a website, spreadsheet, or other location outside of Looker. An embed user is a user who is interacting with a Looker object that is embedded in a location outside of Looker. Embedded content can be public or private (requiring either a Looker login or an SSO authentication).


Entitlements define the Looker resources that a Looker extension can access. The extension will not be able to access a Looker resource unless that resource is listed in the entitlements. Entitlements are defined as part of an application parameter included in a LookML project manifest file.

ephemeral derived table

An ephemeral derived table — more commonly called a temporary derived table — is a derived table that is not written to your database. A temporary derived table can be either a LookML-based (native) derived table or an SQL-based derived table.

see also derived table, temporary derived table

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.

Explore file

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.

explore parameter

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.

see also Explore file


Extensions are web applications built with Looker components that are developed through the Looker extension framework. Some extensions, like the Looker Data Dictionary, are deployed through the Looker Marketplace and are available for all customers. See the extension-examples repository for examples.

see also Looker Data Dictionary, Looker extension framework


fanout (n.), fan out (v.)

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 data set’s primary key.

feature access

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.

field picker

The field picker displays the dimensions and measure applicable to the data shown in an Explore. The Looker developer or admin configures these dimension and measure options. The field picker may also display filter-only fields.

filter expression

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.

  1. 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.
  2. 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.


group, user group

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.


Help Center

Looker’s Help Center contains articles written by Looker SMEs about specific use cases, best practices, and troubleshooting scenarios.



Integrated development environment. Looker’s internal LookML editor, or an editor used to create and modify an extension. Examples of the latter are Visual Studio Code, Intellij, and WebStorm.

incremental persistent derived table

An incremental persistent derived table is a type of persistent derived table (PDT) that is built incrementally, meaning that Looker appends fresh data to the table in specified increments, instead of rebuilding the entire table. This can lead to faster build times for your PDTs and less strain on your database. The increment is defined using the increment_key parameter. Incremental PDTs can be LookML-based (native) derived tables, SQL-based derived tables, or aggregate tables.

see also persistent derived table


The server (or cluster of servers) that hosts Looker. Each client uses a production server (and, potentially, a staging server).


  • (n.) The join parameter enables you to 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.


Labs feature

The Labs panel under the Admin menu lists Looker’s new under-development features. These must be enabled by a Looker admin.

legacy feature

Some product features have a legacy feature option that allows for the continued use of the legacy feature for a period of time (which may be useful for developing and implementing a migration plan). The Admin section of Looker lists the features for which the legacy feature option can be turned on.


see also Looker expression

Liquid parameter

In Looker, a Liquid parameter is a LookML parameter field that has been created using elements of the Liquid templating language.

Liquid variable

A Liquid variable is an element of the Liquid templating language that can be used with LookML to create dynamic content.

Look (n.)

A 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.

Looker API

The Looker API is a secure, “RESTful” application programming interface for managing your Looker instance and fetching data through the Looker data platform. You can write applications or automation scripts to provision new Looker user accounts, run queries, schedule reports, etc. Just about anything you can do in the Looker application you can do through the Looker API.

Looker Cloud

Looker Cloud means the product is installed and provisioned to a customer on a web-connected platform that is run in a third-party hosting facility designated by Looker. For more information, see the Cloud Security Architecture section of Looker’s security webpage.

Looker Data Dictionary

The Looker Data Dictionary is an extension — a web application built using Looker components — developed using the Looker extension framework and deployed through the Looker Marketplace. The Looker Data Dictionary extension provides a dedicated, centralized interface for searching through all Looker fields and descriptions in an Explore. To use the Looker Data Dictionary, Looker admins must enable the Extension Framework and Marketplace features.

see also extension, Looker extension framework

Looker expression

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.

Looker extension framework

The Looker extension framework is a development framework that significantly reduces the effort and complexity of building custom JavaScript data applications and tools. To use the Looker extension framework, Looker admins must enable the Extension Framework feature.

see also extension

Looker Marketplace

The Looker Marketplace is a central location for finding, deploying, and managing many types of Looker content, such as Looker Blocks, applications, visualizations, and plug-ins. To access and use the resources available from the Looker Marketplace, Looker admins must enable the Marketplace feature.


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.

LookML-based derived table

More often referred to as native derived tables, a LookML-based derived table is a derived table whose query is defined in LookML terms, referring to LookML dimensions and measures in your model. Native derived tables can be temporary or persistent.

see also derived table, persistent native derived table, temporary derived table

LookML dashboard

A LookML dashboard is written entirely using LookML (as opposed to a user-defined dashboard, which is created by using the visualization editor).

see also user-defined dashboard

LookML Diagram

The LookML Diagram is an entity relationship diagram of a LookML model that visually depicts relationships between its LookML objects. It is an extension — a web application built using Looker components — developed using the Looker extension framework and deployed through the Looker Marketplace.

see also extension, Looker extension framework, Looker Marketplace, LookML object

LookML object

LookML objects are the models, Explores, views, and fields that have been defined, in LookML, in a project, including files imported from another project. You can view LookML object relationships in the object browser or the LookML Diagram extension.


manifest, manifest file

A manifest (or project manifest) file is where you set project-level settings, such as those for specifying other projects to import into the current project, defining LookML constants, specifying model localization settings, and adding extensions and custom visualizations to your project.


see Looker Marketplace

materialized view

A materialized view is a type of persistent derived table (PDT) that leverages your database’s persistence functionality. This functionality is available for database dialects that support materialized views. Depending on your dialect, a materialized view can consume large resources, so it is important that you understand your dialect’s implementation of materialized views.


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.

Merged Results

The Merged Results feature allows you to 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.

metadata, IDE metadata

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.


A model is the semantic layer in Looker that controls logic and gates data access for users. This is created by developers as a model file within the LookML project, and contains information about which tables to use and how they should be joined together. Multiple models can exist for the same database connection in a single LookML project, and each model can expose different data to different users.

model file

Inside a LookML project, a model file specifies a single database connection, the set of Explores that use that connection, and the Explores themselves, as well as how they should be joined together.

model set

A model set defines what data and LookML fields a user or group can see. An admin can select a combination of LookML models to which a user or group should have access. It must be used as part of a role to have any effect.

see also role


native derived table

Sometimes referred to as LookML-based derived tables, native derived tables are derived tables that have queries defined in LookML terms, referring to LookML dimensions and measures in your model. Native derived tables can be temporary or persistent.

see also derived table, persistent native derived table, temporary derived table


Object browser

The object browser panel in the Looker IDE allows users to view all the objects in a project in one place, along with the hierarchical relationships between them.


see LookML object



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.

permission set

Permission sets are combined with model sets in a role.

see also role

persistent derived table

A persistent derived table (PDT) is a derived table that is stored in the scratch schema of a database and can be regenerated on a schedule of your choosing. It can be referenced in a query without running the underlying SQL each time it is called. A PDT can be a native derived table or a SQL-based derived table.

see also derived table

persistent native derived table

A persistent native derived table is a LookML-based derived table that is persistent, meaning it is stored in the scratch schema of a database and can be regenerated on a schedule of your choosing. It can be referenced in a query without running the underlying SQL each time it is called.

see also derived table, native derived table

persistent SQL-based derived table

A persistent SQL-based derived table is a SQL-based derived table that is persistent, meaning it is stored in the scratch schema of a database and can be regenerated on a schedule of your choosing. It can be referenced in a query without running the underlying SQL each time it is called.

see also derived table, SQL-based derived table

primary key

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.

primary query

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.

Production Mode

In Production Mode, changes that have been made in Development Mode (but not pushed to production) are not yet reflected in the data model shared by all users. In Production Mode, LookML files are treated as read-only. A developer can enter Development Mode to make changes to LookML files and push those changes for others to see in Production.

project, LookML project

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.


Query Time Zone

Query Time Zone is an admin setting for the time zone in which to show dates and times when querying.

see also Database Time Zone, time zone settings



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.

see also model set, permission set


scratch schema

A scratch schema is a schema in the underlying database that is designated to store Looker PDTs.

see also persistent derived table


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 have been renamed folders as of Looker 6.20.

see also folder

SQL-based derived table

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.

see also derived table, persistent SQL-based derived table, temporary derived table

SQL Runner

Accessible through the Develop menu or from an Explore (with the appropriate permissions), SQL Runner lets users run raw SQL against their allowed connections. SQL Runner can be used to perform database functions, create and add derived tables to projects, to leverage the EXPLAIN function, among other uses.


A subfolder is a folder that is stored within another folder. Folders were called Spaces prior to Looker 6.20.


A subparameter is a parameter that can be used under another (parent) parameter in order to further define, refine, or specify how that parameter functions.


A subspace is a Space that is stored within another Space. Spaces have been renamed folders as of Looker 6.20.

substitution operator

The dollar sign ($) is a substitution operator in Looker, and helps to make LookML code more reusable and modular. You can use this syntax to reference LookML objects that have already been defined.

symmetric aggregates

Symmetric aggregates are functions in Looker that successfully return results for aggregations or measures. They help define the correct relationship between tables, thereby avoiding fanouts.

system time zone

The system time zone is the time zone for which the server running Looker is configured.

see also time zone settings


table calculation

Table calculations are similar to spreadsheet formulas and are performed on the results of a query, after the query has executed.

temporary derived table

A temporary derived table — sometimes called an “ephemeral” derived table — is temporary and not written to your database. A temporary derived table can be either a LookML-based (native) derived table, or an SQL-based derived table.

see also derived table, native derived table, SQL-based derived table


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.

time zone settings

Looker admins and users have a variety of options to convert and display time-based data in specific time zones.

see also Application Time Zone, Database Time Zone, Query Time Zone, system time zone, User Specific Time Zones


The process of taking source code written in one language and transforming it into another language that has a similar level of abstraction. An example is TypeScript to JavaScript.


Unsubscribe (for alerts and scheduled content deliveries)

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.

For scheduled email deliveries and alert notifications that are sent by email, any user who unsubscribes on behalf of a group email distribution will terminate email deliveries and alert notifications for all users in that group. When recipients are listed separately, when the last remaining recipient unsubscribes from a scheduled content delivery, the schedule is deleted from Looker and deliveries will no longer be sent.

When any user unsubscribes to alert notifications to Slack through either the Slack or Slack Attachment (API Token) integration, the alert is disabled in Looker and notifications will no longer be sent.

User Specific Time Zones

User Specific Time Zones is an admin option that, when enabled, allows users to choose their own time zones. Queries will be created with the time zones of the users who created them.

see also Application Time Zone, Database Time Zone, Query Time Zone, time zone settings

user-defined dashboard, UDD

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.



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.

view file

A view file is where you define the dimensions, measures, and other fields that are used in your LookML model.

see also model

visual drilling

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.

see also model