Added question about RCSI in dedicated SQL pools.

Author: chuckheinzelman

articles/synapse-analytics/synapse-link/faq.yml

@@ -69,4 +69,7 @@ sections:
           What type of encryption is applied to the landing zone?
         answer: |
           For Azure SQL Database, the landing zone is fully managed and is encrypted with the same key as the target Azure Synapse Analytics workspace - either platform-managed or customer-managed. For SQL Server 2022, the landing zone is customer-managed and can be encrypted with either a platform-managed key or a customer-managed key.
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+      - question: |
+          I updated all of the records in my source table. When I ran a query against the dedicated SQL pool I saw all of my data gone. I re-ran the query and all of the data was back - with the updates. Why does this happen?
+        answer: |
+          The ingestion service processes updates as a delete followed by an insert - all in the same transaction. By default, dedicated SQL pools run in READ UNCOMMITTED mode - which allows you to see the changes before the transaction has been committed. To ensure that you do not see these in-process changes, you can turn on READ COMMITTED SNAPSHOT ISOLATION.