Configure Match and Merge > Match model properties > Maximum candidates
  

Maximum candidates

To improve the accuracy and performance of the match process, specify the maximum number of candidates that the match process can use for each record.
The default is 10,000. By default, the match process identifies up to 10,000 candidates for each record. A number higher than 10,000 might affect the performance of the match process because the match process might take time to process a large number of candidates. A number lower than 2000 can result in undermatching and might affect match accuracy.
When the number of candidates for a record exceeds the maximum limit, the match process randomly selects the candidates. The set of candidates might vary for different match and merge jobs.
Note: Effective in the May 2023 release, the ability to set the maximum number of candidates for matching is available for preview.
Preview functionality is supported for evaluation purposes but is unwarranted and is not supported in production environments or any environment that you plan to push to production. Informatica intends to include the preview functionality in an upcoming release for production use, but might choose not to in accordance with changing market or technical circumstances. For more information, contact Informatica Global Customer Support.