HI All, I had gone through advantages of visibilitymap along with discussion on thick index. I have a question. when we have information about visibility of the data, does it make sense to propagate values of expression stored in index through various slots of execution tree? It would be helpful when index is created on immutable function or expression.
I am adding additional columns in the heap tuple returned by index with the expression values stored in the index. For index_only_scan while projecting the values we will treat expression as normal column. It is simple for queries with single table. But, when we have joins, we will need to modify plan to treat expression as normal column. This will involve modifying plan, intermediate slots. Modification in the plan need to be performed after finalizing plan, as we will be able to identify whether we can treat the expression as value only then. Can there be any other alternative? Thanks, Shrish
