pick (#41218)
In the previous FileScanNode, some parts that used conjuncts for
predicate conversion were placed in the init phase. However, for the
Nereids planner, pushing the filter down to the scan happens in the
Translator, which means that the ScanNode can only get the complete
conjuncts in the finalized phase. Therefore, in this PR, I have removed
all conjuncts variables in External for the Nereids planner. They no
longer need to store conjuncts themselves or add them to the ScanNode.
Instead, all places in the ScanNode that use conjuncts should be moved
to the finalized phase.
This refactor also fix a performance issue introduced from #40176 After
introducing the change of generating SelectNode for consecutive projects
or filters, FileScan still adds conjuncts too early in the init phase,
resulting in the discovery of consecutive filters when the upper layer
continues to translate, a selectnode was unexpectedly generated on the
scannode, causing the project to be unable to prune the scannode
columns. However, the Project node trims columns of SelectNode and
ScanNode differently, which causes ScanNode to scan unnecessary columns.
My modification removes the addition of conjuncts in the scannode step,
so that we can keep the structure from ScanNode to Project and achieve
correct column trimming.
56c2a0f523