Update search-performance-tips.md

Updated to reflect how regex can affect query performance.

Author: gmndrg

articles/search/search-performance-tips.md

@@ -7,7 +7,7 @@ author: LiamCavanagh
 ms.author: liamca
 ms.service: cognitive-search
 ms.topic: conceptual
-ms.date: 08/25/2022
+ms.date: 04/20/2023
 ---
 
 # Tips for better performance in Azure Cognitive Search
@@ -132,6 +132,11 @@ As this hypothetical scenario illustrates, you can have configurations on lower
 
 An important benefit of added memory is that more of the index can be cached, resulting in lower search latency, and a greater number of queries per second. With this extra power, the administrator may not need to even need to increase the replica count and could potentially pay less than by staying on the S1 service.
 
+### Tip: Consider alternatives to regular expression queries
+
+[Regular expression queries](query-lucene-syntax#bkmk_regex.md) or regex can be particularly expensive. While they can be very useful for complex searches, they also may require a lot of processing power to be executed, especially if the regular expression has a lot of complexity or when searching through a large amount of data. This would result in high search latency. In order to reduce the search latency, try to simplify the regular expression or break the complex query down into smaller, more manageable queries. 
+
+
 ## Next steps
 
 Review these other articles related to service performance: