---
sourceDocument: Zurich ServiceNow AI Platform Administration
sourceDocumentLink: https://www.servicenow.com/docs/r/zurich/platform-administration

 Release :

    - zurich

ft:locale :

    - en-US

ft:publication_title :

    - Zurich ServiceNow AI Platform Administration

ft:clusterId :

    - platadm

bundleId :

    - platadm

workflow :

    - Platform


---

# Indexed sources

# Indexed sources in AI Search {#ariaid-title1}

* Release version: Zurich
* 
* Updated July 10, 2026
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 5 minutes to read

Summarize  
![AI sparkle icon](https://servicenow.com/docs/portal-asset/ai-sparkle-icon) Summarized using AI  
This content was generated using new OpenAI-powered functionality. Results are provided on an as is basis and are not guaranteed to be accurate or complete.  

## Summary of Indexed sources in AI Search

Indexed sources in AI Search designate ServiceNow AI Platform® tables and external document sets containing alphanumeric text and string fields that you want to make searchable.
AI Search ingests and indexes these fields from table records or external documents to enable efficient search functionality within your ServiceNow environment.
Show full answer Show less  

## Indexed Source Types

* **Internal indexed source:** Retrieves and indexes text and string content from ServiceNow AI Platform tables and their child tables. Certain tables are excluded from indexing, and remote tables cannot be indexed internally.
* **External indexed source:** Retrieves content from external repositories or remote tables using an external content schema table reference.

**Note:** Unicode characters in the High Surrogate Area are replaced with spaces during indexing.

## Search Performance Considerations

Several factors influence AI Search performance related to indexing:

* **Index size:** Larger indexes take longer to search; avoid indexing unnecessary content.
* **Number of indexed sources:** More sources increase search time even if total index size is the same.
* **Number of indexed fields:** Indexing more fields slows down search independently of size or source count.
* **Indexing frequency:** Frequent updates can compete with search for resources, reducing response time.

## Retention Policies and Filter Conditions

To optimize index size and update frequency, you can define retention policies and filter conditions to exclude records based on age or status (e.g., excluding records older than two years or with specific statuses like Open). These settings:

* Keep search results current.
* Reduce index size and update frequency.
* Enable automatic purging of stale records.

**Note:** Retention policies are mandatory for indexed sources based on the Task \[task\] table and its extensions, and optional for others.

## Indexed Source Configuration

* **Attributes:** Control indexing behavior at the record level for an indexed source.
* **Field settings:** Control indexing behavior for specific fields within indexed records.

These configurations allow fine-tuning of what content is indexed and how it is processed.

## Indexing Behavior

Once defined, AI Search automatically indexes creates, updates, and deletes of source table records and configured child tables. Unmodified records are indexed only during full table indexing, which can be performed as needed.

Pre-configured indexed sources index only text and string fields; numeric fields can be used for filtering but not for search queries unless their values are copied into text/string fields.

## Special Considerations

* **Knowledge articles:** By default, AI Search indexes content from knowledge blocks but can be configured to exclude this content.
* **Multiple indexed sources:** Only one active indexed source per ServiceNow AI Platform table is allowed. Duplicate sources created by plugins are inactive by default.

## Additional Features and Controls

* **Indexed source guardrails:** Help reduce index size and improve search performance by limiting task and alert records indexed.
* **Semantic index configuration:** Enables configuring semantic indexing settings using AI Search's RAG framework.
* **Catalog variable indexing:** Supports indexing searchable content from variables on Catalog Item records with configurable eligibility and variable sets.

## Practical Benefits for ServiceNow Customers

By leveraging indexed sources in AI Search, customers can:

* Make relevant ServiceNow Platform records and external documents easily searchable through AI Search.
* Optimize search performance by controlling indexed content scope, frequency, and field-level settings.
* Keep search results up to date and relevant by applying retention policies and filters to exclude stale or frequently changing records.
* Customize indexing behavior to fit organizational needs, including semantic search capabilities and catalog content indexing.  
Indexed sources designate ServiceNow AI Platform® tables and external document sets with alphanumeric text and string field content that you want to make searchable. AI Search ingests text and string fields from table records or external documents and stores their searchable alphanumeric content in its search index.
For instructions on creating an indexed source, see [Create an indexed source](https://www.servicenow.com/docs/kn3MPRHuFsU5uDmL0JU2Hg "Define an indexed source to make content and metadata from ServiceNow AI Platform table records searchable using AI Search.").

## Indexed source types {#indexed-sources-ais__section_fbz_g54_3nb}

AI Search supports the following indexed source types.

Internal indexed source
:   An internal indexed source retrieves alphanumeric content and metadata from text and string fields on ServiceNow AI Platform records. It includes a unique name and a reference to a ServiceNow AI Platform table with records that you want to make searchable. AI Search extracts and indexes searchable alphanumeric content and metadata from text and string fields on records in this table and in any of its child tables that you configure for indexing.
:   AI Search excludes some ServiceNow AI Platform tables from indexing. You can't define indexed sources for these excluded tables or their derived tables. For a list of excluded tables, see [ServiceNow AI Platform tables excluded from AI Search indexing](https://www.servicenow.com/docs/vuEWWjVRN_e7k2pBJFAagA "AI Search excludes the following ServiceNow AI Platform tables when indexing content. You can't configure these tables, or tables derived from them, as AI Search indexed sources.").
:   You can't index [remote tables](https://www.servicenow.com/docs/access?context=remote-tables&version=zurich&pubname=zurich-servicenow-platform&ft:locale=en-US) with internal indexed sources. To index content from a remote table, create an external indexed source.

External indexed source
: An external indexed source retrieves alphanumeric content and metadata from text and string fields of documents in an external repository or a [remote table](https://www.servicenow.com/docs/access?context=remote-tables&version=zurich&pubname=zurich-servicenow-platform&ft:locale=en-US). It includes a unique name and a reference to an external content schema table instead of a ServiceNow AI Platform table. For more details on configuring indexed sources for external content, see [Indexing and searching external content in AI Search](https://www.servicenow.com/docs/YMRjaDHkGyohFBjB3uSkYQ "With a subscription for the External Content for AI Search plugin, you can enable AI Search users to search content and metadata from documents in external repositories and remote tables.").  
Note:  
AI Search doesn't index Unicode characters from the High Surrogate Area (code units in the range U+D800 to U+DBFF). Characters from this range are replaced with spaces during indexing.

## Search performance considerations for indexing {#indexed-sources-ais__id_bzn_2b1_5jc}

Search performance for AI Search is affected by several customer-controlled factors related to content indexing. Changes to these factors can impact search performance as follows.

Index size
:   Indexing more content produces a larger index, which takes more time to search. Avoid indexing content that isn't needed for search.
:   Indexing large source tables, such as the Task \[task\] table and tables that extend it, can add significant numbers of records to the AI Search index.

Number of indexed sources
:   An index with more indexed sources takes longer to search than one with fewer indexed sources. This is true even if the two indexes are the same size.

Number of indexed fields
:   Increasing the number of fields you index across your indexed sources makes the system take longer to find search results. This effect is independent of index size and number of indexed sources.

Indexing frequency
:   The more often your indexed content is synchronized and updated, the more often search will compete with indexing for compute resources, increasing search response time. This is especially pertinent for indexed sources
    with frequently modified fields.

## Indexed source retention policies and filter conditions {#indexed-sources-ais__id_k3x_fc1_5jc}

To limit the size of your index and the frequency of index updates, you can define retention policies and filter conditions for your indexed sources.{#indexed-sources-ais__retention-policies-filter-conditions-p1}

As an example, you can define a retention policy for an indexed source to exclude records that are more than two years old. This policy keeps your search results more current and
reduces the size of your index. Changes made to the excluded records don't trigger index updates, so this policy also reduces indexing frequency.{#indexed-sources-ais__retention-policies-filter-conditions-p2}

Similarly, you can define a filter condition for an indexed source that excludes source table records with a specific status, such as Open. This filter condition reduces the number of
records indexed from the source table, which in turn reduces the total amount of data you index. Excluding open records that have frequent updates also reduces indexing frequency.{#indexed-sources-ais__retention-policies-filter-conditions-p3}

AI Search also uses your retention policy and filter condition settings to automatically purge stale records from the index, reducing its size.{#indexed-sources-ais__retention-policies-filter-conditions-p4}

To learn more about creating retention policies and filter conditions for your indexed sources, see [Indexed source retention policies and filter conditions](https://www.servicenow.com/docs/WlmYUuk1IlpdDh2VuW7eyg "To limit the set of records indexed from source tables, you can configure retention policies and filter conditions for your indexed sources. AI Search also uses these settings to automatically purge stale records from the index, optimizing search performance.").{#indexed-sources-ais__retention-policies-filter-conditions-p5}  
Note:  
Retention policies are required for indexed sources that index records from the Task \[task\] table or tables that extend it. They are optional for other indexed sources.

## Indexed source attributes and field settings {#indexed-sources-ais__section_o2k_yft_xqb}

You can configure attributes and field settings for an indexed source to control indexing behavior for source records. Attributes control the indexed source's behavior at the record level, while field settings define its
behavior for individual fields on indexed records. For more information, including lists of available attributes and field settings, see [Indexed source attributes for AI Search](https://www.servicenow.com/docs/yGPwuTgaQa5eZY5CWqqgCw "An indexed source attribute defines indexing behavior for all records from an indexed source.") and [Field settings for AI Search](https://www.servicenow.com/docs/chu9xz3ePPnXNF5dQMEGzg "A field setting controls indexing behavior for a specified field (column) on all records from an indexed source.").

## Indexing content from an indexed source {#indexed-sources-ais__section_awl_hgt_xqb}

After you define an indexed source, AI Search begins automatically indexing to reflect changes to records in the selected source table and its specified child tables. The results of all record create, update, and delete operations in these tables are reflected in the search index. AI Search doesn't index content from unmodified records in these tables until you perform a full table index. For more information on indexing behavior, including steps for full table indexing, see [Indexing content from AI Search indexed sources](https://www.servicenow.com/docs/qC2dm_CkVDFRyYJ6_hzQ7g "AI Search indexes records on indexed source tables to make their content searchable.").  
Note:  
The pre-configured indexed sources included with AI Search only index content from text and string fields on source records. When searching records from these indexed sources, you can use numeric fields to facet or filter your search results, but you can't find records using their numeric field values. To search on a record's numeric field values, copy them into a text or string field so they can be indexed.

## Indexing content from knowledge articles {#indexed-sources-ais__section_rfb_ldq_xdc}

When indexing content from records in the Knowledge \[kb_knowledge\] table, AI Search defaults to including content defined in knowledge blocks. Administrators can override this default behavior and configure AI Search to exclude content from knowledge blocks when indexing knowledge articles. For details on making this change, see [Exclude knowledge block content from the AI Search index](https://www.servicenow.com/docs/x9h3AeHeLFhFP~nMUdIqgw "Prevent AI Search from indexing content found in your knowledge blocks.").

## Multiple indexed sources for the same ServiceNow AI Platform table {#indexed-sources-ais__section_clb_vmk_gtb}

You can't create more than one indexed source for a single ServiceNow AI Platform table. However, plugins and applications may define duplicate indexed sources for a ServiceNow AI Platform table. For example, the base system includes an indexed source defined for the User \[sys_user\] table, but a plugin or application might define a second indexed source for this table under a different name.  
Note:  
Only one indexed source can be active at a time for a given ServiceNow AI Platform table. The system makes duplicate indexed sources for a table inactive by default. Before you can make one of these duplicate sources active, you must edit the currently active source and make it inactive. AI Search only indexes content and metadata from active indexed sources.
* **[Create an indexed source](https://www.servicenow.com/docs/kn3MPRHuFsU5uDmL0JU2Hg)**   
  Define an indexed source to make content and metadata from ServiceNow AI Platform® table records searchable using AI Search.
* **[Indexed source retention policies and filter conditions](https://www.servicenow.com/docs/WlmYUuk1IlpdDh2VuW7eyg)**   
  To limit the set of records indexed from source tables, you can configure retention policies and filter conditions for your indexed sources. AI Search also uses these settings to automatically purge stale records from the index, optimizing search performance.
* **[Indexed source guardrails](https://www.servicenow.com/docs/q1SbzwFT7xePuwsICiQvFg)**   
  Reduce index size and increase search performance with guardrails that limit the number of task and alert source records indexed from indexed sources.
* **[Semantic index configuration for indexed sources](https://www.servicenow.com/docs/uo3jY_6a4vWWwhSgFodUTw)**   
  The AI Search generalized RAG (Retrieval-Augmented Generation) framework offers a streamlined way to configure semantic indexing settings for records indexed from ServiceNow AI Platform® tables.
* **[Exclude knowledge block content from the AI Search index](https://www.servicenow.com/docs/x9h3AeHeLFhFP~nMUdIqgw)**   
  Prevent AI Search from indexing content found in your knowledge blocks.
* **[Activate indexing of catalog variable content on Catalog Item records](https://www.servicenow.com/docs/GaozVk_PDmg7GNQkPq804g)**   
  Activate indexing of searchable content from variables on Catalog Item records. Configure the set of Catalog Items eligible for catalog variable indexing and the set of variables to index.
* **[Indexed source attributes for AI Search](https://www.servicenow.com/docs/yGPwuTgaQa5eZY5CWqqgCw)**   
  An indexed source attribute defines indexing behavior for all records from an indexed source.
* **[Field settings for AI Search](https://www.servicenow.com/docs/chu9xz3ePPnXNF5dQMEGzg)**   
  A field setting controls indexing behavior for a specified field (column) on all records from an indexed source.
* **[Indexing content from AI Search indexed sources](https://www.servicenow.com/docs/qC2dm_CkVDFRyYJ6_hzQ7g)**   
  AI Search indexes records on indexed source tables to make their content searchable.