Database Reference
In-Depth Information
Figure 34-12.
Execution plan with a Columnstore Index Scan and batch-mode execution (SQL Server 2012)
Figure
34-13
shows the execution plan of the query in SQL Server 2014. As you can see, the execution plan is
significantly simpler and does not include
Parallelism/Exchange
operators. SQL Server 2014 supports batch-mode
execution even in cases of
tempdb
spills.
Figure 34-13.
Execution plan with a Columnstore Index Scan and batch-mode execution (SQL Server 2014)
Table
34-4
illustrates the execution statistics for the queries. It is worth noting that, even though SQL Server 2014
performance improvements are marginal in batch-mode execution, this situation would change in the case of
tempdb
spills, when SQL Server 2012 would switch to row-mode execution.
Table 34-4.
Execution statistics: Columnstore Index Scan and parallel execution plan
CPU Time (ms)
Elapsed Time (ms)
SQL Server 2012
703
246
SQL Server 2014
687
220