Read Committed Snapshot Isolation
RCSI (Read Committed Snapshot Isolation) is something that makes databases go faster. But today I read a post by Michael J Swart that shows a much needed fix if you want to do ETL from an busy database with RCSI.
You need to use WITH(READCOMMITTEDLOCK), if your source table can get rows in concurrent batches.
I think both go into my toolbox for future use.
Find them at https://lnkd.in/eNDXy9cq and https://lnkd.in/eeC2BnYe