Using Trace to Monitor and Audit Analysis Services - Microsoft SQL Server 2008 Analysis Services - page 775

data . That's obviously not the right description; it's a result of a bug in Analysis Services.
It wasn't fixed by the time we wrote this topic, but it might be by the time you look at
your own SQL Server Profiler.

You'll find something else interesting as you look closely at Figure 38.9. It looks like the
server started writing data before it read the data. That is, you might see the Progress
Report End event with the ReadData subclass come after the one with the WriteData
subclass. This can occur because of the asynchronous nature of the execution. If a writing
operation is fast, it can get its event into the queue before the reading operation.

Reporting the Progress of Partition Processing

Processing partitions is bit different from processing of dimensions, but not by much.
Figure 38.10 shows the steps that are typically reported during processing of a partition.
Like the processing of dimension attributes, it starts with executing SQL statements. In
addition, partition processing also has ReadData and WriteData subclasses. However,
unlike the processing of dimensions, the processing of partitions has an additional step.
The server has to process aggregations, too, so you would see events for the
BuildAggsAndIndexes step in SQL Server Profiler during processing of the partition.

ExecuteSQL

ReadData GroupData GroupDataRecord

WriteData

Aggregate

BuildIndex

MergeAggsOnDisk

BuildAggsAndIndexes

BuildIndex for Flexible
Aggregations

BuildIndex for Rigid
Aggregations

FIGURE 38.10

SQL Server Profiler shows events that report the progress of processing the

partition.