Filtering and Calculations in SQL Queries
As we saw in Find Out What's Taking So Long, it took a lot longer to use an element to filter data compared to using a WHERE clause in the SQL query. This is generally true: if the datasource is SQL-based or accepts queries, you should do all the filtering and calculations that you can in the query. The database server is going to process them much more quickly than the Logi application on the web server can.
However, many datasources do not accept queries and that's one of the reasons we have data filtering and manipulation elements.