Swam engine buffer size problem
Then it multiplies the estimated size of a row by the value of DefaultBufferMaxRows to obtain a preliminary working value for the buffer size. The data flow engine begins the task of sizing its buffers by calculating the estimated size of a single row of data. This project property overrides the RunInOptimizedMode property of Data Flow tasks at design time. Optimized mode improves performance by removing unused columns, outputs, and components from the data flow.Ī property with the same name, RunInOptimizedMode, can be set at the project level in SQL Server Data Tools (SSDT) to indicate that the Data Flow task runs in optimized mode during debugging. Indicate whether the Data Flow task runs in optimized mode (RunInOptimizedMode property). The engine may also use more threads than specified in this property, if necessary to avoid concurrency issues. However, the engine will not use more threads than it needs, regardless of the value of this property. The default is 10, with a minimum value of 3. This property provides a suggestion to the data flow engine about the number of threads to use. Set the number of threads that the task can use during execution, by setting the EngineThreads property. The default maximum number of rows is 10,000. The default buffer size is 10 megabytes, with a maximum buffer size of 2^31-1 bytes. Set the AutoAdjustBufferSize property to indicate whether the default size of the buffer is calculated automatically from the value of the DefaultBufferMaxRows property. You can specify multiple directories by delimiting the directory names with semicolons.ĭefine the default size of the buffer that the task uses, by setting the DefaultBufferSize property, and define the maximum number of rows in each buffer, by setting the DefaultBufferMaxRows property. You might want to specify other folders to put the temporary files on a different or faster hard disk drive, or to spread them across multiple drives. By default, these properties contain the values of the TEMP and TMP environment variables. Specify the locations for temporary storage of buffer data (BufferTempStoragePath property) and of columns that contain binary large object (BLOB) data (BLOBTempStoragePath property). You can configure the following properties of the Data Flow task, all of which affect performance: The properties discussed in this section must be set separately for each Data Flow task in a package.