for (Table catalog_tbl : tables) {
MaterializedViewInfo catalog_view = this.vp_views.get(catalog_tbl);
assert(catalog_view != null);
assert(catalog_view.getGroupbycols().isEmpty() == false) :
String.format("Missing vertical partitioning columns in %s when trying to process %s\n%s\nCACHED: %s",
catalog_view.fullName(), catalog_stmt.fullName(), CatalogUtil.debug(catalog_view), CatalogUtil.debug(this.vp_columns.get(catalog_tbl)));
Collection<Column> view_cols = CatalogUtil.getColumns(catalog_view.getGroupbycols());
assert(view_cols.isEmpty() == false) : "Missing vertical partitioning columns in " + catalog_view.fullName() + " when trying to process " + catalog_stmt.fullName();
Column partitioning_col = catalog_tbl.getPartitioncolumn();
assert(partitioning_col != null);