Predicate Pushdown and Columnstore Indexes

Predicate pushdown in SQL Server is a query plan optimisation that pushes predicates down the query tree, so that filtering occurs earlier within query execution than implied by the logical query execution ordering.

So with an inner join query for example, a predicate that appears in the WHERE clause and that logically […] “Predicate Pushdown and Columnstore Indexes”

Updating Type 2 SCD Attributes using the T-SQL Merge Statement

During Matt Masson’s SSIS Performance Design Patterns pre-con day at SQLBits last year, Matt discussed the use of the T-SQL Merge statement for implementing Type 2 SCD attribute updates.

In one of his posts on Microsoft’s SSIS Team Blog, he references the source of this idea as being […] “Updating Type 2 SCD Attributes using the T-SQL Merge Statement”

Rowgroup Elimination for Clustered Columnstore Indexes

When bulk loading data into clustered columnstore indexes – either to populate them initially or during subsequent loads – an important design consideration is the resulting performance of the load.

But the way in which the table is queried after the load is also a factor to consider during the design stage. […] “Rowgroup Elimination for Clustered Columnstore Indexes”