> ## Documentation Index
> Fetch the complete documentation index at: https://docs.usebracket.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Primary Keys

> How Bracket uniquely identifies records

## Summary

To support safe syncing, Bracket matches records based on their primary key. Below, we layout what Bracket uses for primary keys depending on the data source, and if there is any prep work needed from you.

| Tool                                            | Primary key                             | Preparation needed?                                 |
| ----------------------------------------------- | --------------------------------------- | --------------------------------------------------- |
| [Postgres](/connecting/postgres_connecting)     | Unique field created by Bracket or user | Potentially, see [guide](/connecting/postgres_pkey) |
| [Salesforce](/connecting/salesforce_connecting) | Salesforce Record ID                    | No                                                  |
| [Hubspot](/connecting/hubspot_connecting)       | Hubspot record ID                       | No                                                  |
| [Airtable](/connecting/airtable_connecting)     | Airtable record ID                      | No                                                  |
| [Google Sheets](/connecting/gsheets_connecting) | Unique field created by user            | Yes, see [guide](/connecting/gsheets_pkey)          |
| [MySQL](/connecting/mysql_connecting)           | Unique field created by user            | Yes                                                 |
| [MongoDB](/database/mongodb_connecting)         | MongoDB object ID                       | No                                                  |
| [Firestore](/database/firebase_connecting)      | Firestore document ID                   | No                                                  |
| [Snowflake](/database/snowflake_connecting)     | Unique field created by user            | Yes, see [guide](/connecting/snowflake_pkey)        |
| [Notion](/connecting/notion_connecting)         | Notion object ID                        | No                                                  |