HashMap<AbstractExpression, Set<AbstractExpression>> valueEquivalence = new HashMap<>();
int i = 0;
Column partitioningCol = targetTable.getPartitioncolumn();
boolean setEquivalenceForPartitioningCol = false;
for (Column col : insertStmt.m_columns.keySet()) {
if (partitioningCol.compareTo(col) == 0) {
List<SchemaColumn> partitioningColumns = stmtTargetTableScan.getPartitioningColumns();
assert(partitioningColumns.size() == 1);
AbstractExpression targetPartitionColExpr = partitioningColumns.get(0).getExpression();
TupleValueExpression selectedExpr = subquery.getOutputExpression(i);
assert(!valueEquivalence.containsKey(targetPartitionColExpr));