public static SelectStatement filterEntryProjection(SelectStatement in, PartitionEntry jre)
throws PEException {
PartitionEntry actual = jre.getActualEntry();
SelectStatement expecting = null;
if (actual instanceof OriginalPartitionEntry)
expecting = ((OriginalPartitionEntry) actual).getChildCopy();
else expecting = actual.getJoinQuery(null);
ListSet<ColumnKey> ec = new ListSet<ColumnKey>();
for (ExpressionNode en : expecting.getProjection()) {
ExpressionNode targ = ExpressionUtils.getTarget(en);
if (targ instanceof ColumnInstance) {
ColumnKey was = ((ColumnInstance) targ).getColumnKey();
ColumnKey isnow = in.getMapper().copyColumnKeyForward(was);
if (isnow == null) {
throw new SchemaException(Pass.PLANNER, "Lost column during lookup table join");
}
ec.add(isnow);
} else if (targ instanceof FunctionCall) {
ExpressionNode exn = targ;
RewriteKey rk = in.getMapper().mapExpressionToColumn(exn);
while (rk == null && (exn.getParent() instanceof ExpressionNode)) {
exn = (ExpressionNode) exn.getParent();
rk = in.getMapper().mapExpressionToColumn(exn);
}
if (rk != null) {
ec.add((ColumnKey) rk);
}
}
}
for (Iterator<ExpressionNode> iter = in.getProjectionEdge().iterator(); iter.hasNext(); ) {
ExpressionNode en = ExpressionUtils.getTarget(iter.next());
if (en instanceof ColumnInstance) {
ColumnKey ck = ((ColumnInstance) en).getColumnKey();
if (!ec.contains(ck)) iter.remove();
}
}
return in;
}
