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Bulk writes indeed are fast but will not be logged. If that is not what you want, consider procedure calls with table valued parameters. That way we have realised significant write improvements.


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The only isolation level that influences writes is SNAPSHOT (and the READ_COMMITTED_SNAPSHOT). Snapshot isolation requires row versioning and row versioning requires extra writes. Read Understanding Row Versioning-Based Isolation Levels. Now about the 'super-fast' part of the question: the 'super-fast' option for INSERT is the bulk insert path. This ...


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An ORM requires information about the first write (SCOPE_IDENTITY or such) to complete the second write. This means 2 (with an OUTPUT clause) or 3 database (with SELECT SCOPE_IDENTITY) calls in general in a client side transaction. No amount of tinkering with isolation levels will eliminate these 2 or 3 calls. If you want more performance, then the best ...


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Is there any extra cost associated with, for example, having to go potentially further back in the undo data to return the records? Example: You have a table getting one insert every minute. If a SERIALIZABLE transaction started at 4:00pm, and queried that table at 4:15pm, then it will have to read at least 15 undo records to return to the state of ...


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RCSI applies only to reads. Writes take normal locks. See Understanding Row Versioning-Based Isolation Levels: [RCSI] uses update locks on the data rows selected. Acquires exclusive locks on actual data rows to be modified. No update conflict detection. So your expectation that under RCSI you cannot block is wrong. However, you have a valid point on ...



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