SQL Server SSIS package

Synchronous and Asynchronous transformation

Synchronous transformation is quicker than asynchronous.

But merge join is faster than lookup sometimes, while merge join is asynchronous.

"A asynchronous component requires all the rows from the upstream component
before it begins processing the rows, to do some modification on the data,
and ususally generates a differant number of rows.

In a way, they act as both destination and source, thus they generate
different LineageID for the output columns. Since the mappings in the
downstream is done using the LineageID you need to restore these mappings."

Blocking, Non Blocking and Partial blocking

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