http://www.bidn.com/blogs/Daniel/ssas/1361/ssis-blocking-non-blocking-and-partially-blocking-transformations
http://www.developer.com/db/top-10-common-transformations-in-ssis.html
A Non Blocking transformation is a dam that just lets the water spill over the top
A Blocking transformation is a dam that lets nothing through until the entire volume of the river has flowed into the dam
Synchronous are components like the Conditional Split or Derived Column Transformation where rows flow into memory buffers in the transformation and the same buffers come out.
Asynchronous transformation has two types, fully blocking and partial blocking.
Synchronous = non blocking. input and output use same memory buffer
Asynchronous = partial blocking and blocking. Need new memory buffer for output
blocking = no output until all input memory are processed
Merge Join is similar to database join
Merge needs input to be sorted but Union All does not requires this
Non Blocking
- Audit
- Character Map
- Conditional Split
- Copy Column
- Data Conversion
- Derived Column
- Import Column
- Lookup
- Multicast
- Percentage sampling
- Row count
- Row sampling
- Script component
Partially Blocking
- Data mining
- Merge
- Merge Join
- Pivot/Unpivot
- Term Extraction
- Term Lookup
- Union All
Blocking
- Aggregate
- Fuzzy Grouping
- Fuzzy Lookup
- Sort
