pred column also needs to be filtered by expr, exclude delete condition column, delete condition column not need to be filtered, query engine does not need it, after _output_column_by_sel_idx, delete condition materialize column will be erase at the end of the block.
Eg:
delete from table where a = 10;
select b from table;
a column only effective in segment iterator, the block from query engine only contain the b column, so no need to filter a column by expr.
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