Address Issue bigdawg-istc#15 by attempting to distinguish join types…

… and acting accordingly

src/main/java/istc/bigdawg/islands/SciDB/operators/SciDBIslandJoin.java

@@ -260,6 +260,9 @@ public String generateJoinFilter() throws IslandException {
 		return null;
 	}
 
-
+	@Override
+	public JoinType getJoinType() {
+    	return joinType;
+	}
 
 };

src/main/java/istc/bigdawg/islands/operators/Join.java

@@ -4,7 +4,9 @@
 
 public interface Join extends Operator {
 
-	public enum JoinType  {Left, Natural, Right, Cross};
+	// Need to suppor the following join types
+	// https://github.com/postgres/postgres/blob/ab7646ff92c799303b9ee70ce88b89e07dae717c/src/backend/commands/explain.c#L1475
+	public enum JoinType  {Left, Natural, Right, Cross, Inner, Full, Semi, Anti, Simple};
 
 	// creates a default and call this to create a new Join instance
 	public Join construct(Operator child0, Operator child1, JoinType jt, String joinPred, boolean isFilter) throws Exception;
@@ -26,5 +28,5 @@ public enum JoinType  {Left, Natural, Right, Cross};
 	public String getJoinToken();	
 	public Integer getJoinID();
 	public void setJoinID(Integer joinID);
-
+	public JoinType getJoinType();
 };

src/main/java/istc/bigdawg/islands/relational/operators/SQLIslandJoin.java

@@ -22,6 +22,7 @@
 import net.sf.jsqlparser.expression.Parenthesis;
 import net.sf.jsqlparser.parser.CCJSqlParserUtil;
 import net.sf.jsqlparser.schema.Column;
+import org.apache.log4j.Logger;
 
 
 public class SQLIslandJoin extends SQLIslandOperator implements Join {
@@ -99,6 +100,15 @@ public SQLIslandJoin (Map<String, String> parameters, List<String> output, SQLIs
 				((SQLIslandAggregate)o).setSingledOutAggregate();
 			}
 		}
+
+		if (parameters.containsKey("Join-Type")) {
+			try {
+				joinType = JoinType.valueOf(parameters.get("Join-Type"));
+			} catch (IllegalArgumentException e) {
+				// unknown join type
+				Logger.getLogger(this.getClass().getName()).warn("Unknown Join-Type returned: '" + parameters.get("Join-Type") + "'");
+			}
+		}
 
 	}
 
@@ -447,4 +457,9 @@ public String generateJoinPredicate() throws IslandException {
 	public String generateJoinFilter() throws IslandException {
 		return joinFilter != null ? new String(joinFilter): null;
 	}
+
+	@Override
+	public JoinType getJoinType() {
+		return joinType;
+	}
 };

src/main/java/istc/bigdawg/shims/PostgreSQLQueryGenerator.java

@@ -8,13 +8,15 @@
 import java.util.stream.Collectors;
 
 import istc.bigdawg.islands.relational.SQLJSONPlaceholderParser;
+import istc.bigdawg.islands.relational.SQLParseLogical;
 import org.apache.commons.lang3.tuple.ImmutablePair;
 import org.apache.commons.lang3.tuple.Pair;
 
 import istc.bigdawg.islands.operators.Aggregate;
 import istc.bigdawg.islands.operators.CommonTableExpressionScan;
 import istc.bigdawg.islands.operators.Distinct;
 import istc.bigdawg.islands.operators.Join;
+import istc.bigdawg.islands.operators.Join.JoinType;
 import istc.bigdawg.islands.operators.Limit;
 import istc.bigdawg.islands.operators.Merge;
 import istc.bigdawg.islands.operators.Operator;
@@ -65,6 +67,7 @@
 import net.sf.jsqlparser.statement.select.ValuesList;
 import net.sf.jsqlparser.statement.select.WithItem;
 import net.sf.jsqlparser.util.SelectUtils;
+import org.apache.log4j.Logger;
 
 public class PostgreSQLQueryGenerator implements OperatorQueryGenerator {
 
@@ -130,7 +133,6 @@ public void visit(Operator operator) throws Exception {
 
 	@Override
 	public void visit(Join joinOp) throws Exception {
-
 		SQLIslandJoin join = (SQLIslandJoin) joinOp;
 
 		if (!isRoot && join.isPruned()) {
@@ -285,7 +287,7 @@ public void visit(Join joinOp) throws Exception {
 			child0.accept(this);
 		}
 		// Resolve pruning and add join
-		addJSQLParserJoin(dstStatement, t1);
+		net.sf.jsqlparser.statement.select.Join newJoin = addJSQLParserJoin(dstStatement, t1, join.getJoinType());
 
 		if (child1 instanceof Aggregate && stopAtJoin) {
 			List<SelectItem> sil = new ArrayList<>();
@@ -401,8 +403,18 @@ public void visit(Join joinOp) throws Exception {
 				treeWalker = nextGen;
 			}
 
-			((PlainSelect) dstStatement.getSelectBody()).setWhere(CCJSqlParserUtil.parseCondExpression(e.toString()));
-
+			if (newJoin.isSimple()) {
+				// As long as postgres alone is being used to generate query plans, this statement is not typically
+				// reached as the planner doesn't seem to distinguish between INNER JOIN and Simple, even though
+				// technically there is a syntactical distinction.
+				//
+				// One exception is the case of join types we presently don't handle (such as an Anti Join).
+				// Leaving this here, then, is no worse off than things originally were prior to this change.
+				// (4/24/2020)
+				((PlainSelect) dstStatement.getSelectBody()).setWhere(CCJSqlParserUtil.parseCondExpression(e.toString()));
+			} else {
+				newJoin.setOnExpression(e);
+			}
 		}
 
 	}
@@ -1915,13 +1927,37 @@ private List<String> processLeftAndRightWithIndexCond(SQLIslandOperator o, boole
 	 * @param dstStatement
 	 * @param t
 	 */
-	private void addJSQLParserJoin(Select dstStatement, Table t) {
+	private net.sf.jsqlparser.statement.select.Join addJSQLParserJoin(Select dstStatement, Table t, JoinType joinType) {
 		net.sf.jsqlparser.statement.select.Join newJ = new net.sf.jsqlparser.statement.select.Join();
 		newJ.setRightItem(t);
-		newJ.setSimple(true);
+		switch(joinType) {
+			case Simple:
+				newJ.setSimple(true);
+				break;
+			case Left:
+				newJ.setLeft(true);
+				break;
+			case Right:
+				newJ.setRight(true);
+				break;
+			case Cross:
+				newJ.setCross(true);
+				break;
+			case Full:
+				newJ.setFull(true);
+				break;
+			case Inner:
+				newJ.setInner(true);
+				break;
+			default:
+				Logger.getLogger(PostgreSQLQueryGenerator.class).warn("Unknown Join type: " + joinType.toString() + " reverting to simple.");
+				newJ.setSimple(true);
+				break;
+		}
 		if (((PlainSelect) dstStatement.getSelectBody()).getJoins() == null)
 			((PlainSelect) dstStatement.getSelectBody()).setJoins(new ArrayList<>());
 		((PlainSelect) dstStatement.getSelectBody()).getJoins().add(newJ);
+		return newJ;
 	}
 
 	/**