Reading Execution Plans 1: Estimated vs Actual Plans, Operators and Join Algorithms
An execution plan is read right to left, inside out; the first thing to check is not cost percentage but estimated versus actual rows and how many times each operator ran. Where cost percentage misleads in the actual plan of an EF Core Include query, seek/scan/lookup, the measured cost of nested loops, merge and hash joins on the same query, stream and hash aggregates, and going from 2,549 to 689 logical reads with two indexes.
8 Nov 2026
·
10 min
·
6
