fix(griffin) - problem with asof join with where clause. also dangling where...

fix(griffin) - problem with asof join with where clause. also dangling where statement fix. Fixed #307 (#326)

core/src/main/java/io/questdb/griffin/SqlOptimiser.java

@@ -65,6 +65,7 @@ class SqlOptimiser {
     private final ObjList<JoinContext> joinClausesSwap1 = new ObjList<>();
     private final ObjList<JoinContext> joinClausesSwap2 = new ObjList<>();
     private final IntList tempCrosses = new IntList();
+    private final IntList tempList = new IntList();
     private final LiteralCollector literalCollector = new LiteralCollector();
     private final IntHashSet tablesSoFar = new IntHashSet();
     private final IntHashSet postFilterRemoved = new IntHashSet();
@@ -1425,12 +1426,27 @@ class SqlOptimiser {
                 literalCollector.resetNullCount();
                 traversalAlgo.traverse(node, literalCollector.lhs());
 
+                tempList.clear();
+                for (int j = 0; j < literalCollectorAIndexes.size(); j++) {
+                    int tableExpressionReference = literalCollectorAIndexes.getQuick(j);
+                    int position = tempList.binarySearch(tableExpressionReference);
+                    if (position < 0) {
+                        tempList.add(-(position + 1), tableExpressionReference);
+                    }
+                }
+
+                int distinctIndexes = tempList.size();
+
                 // at this point we must not have constant conditions in where clause
                 // this could be either referencing constant of a sub-query
                 if (literalCollectorAIndexes.size() == 0) {
                     // keep condition with this model
                     addWhereNode(model, node);
                     continue;
+                } else if (distinctIndexes > 1) {
+                    int greatest = tempList.get(distinctIndexes - 1);
+                    model.setPostJoinWhereClause(concatFilters(model.getPostJoinWhereClause(), nodes.getQuick(greatest)));
+                    continue;
                 }
 
                 // by now all where clause must reference single table only and all column references have to be valid

core/src/main/java/io/questdb/griffin/SqlParser.java

@@ -717,8 +717,13 @@ public final class SqlParser {
         // expect [where]
 
         if (tok != null && isWhereKeyword(tok)) {
-            model.setWhereClause(expr(lexer, model));
-            tok = optTok(lexer);
+            ExpressionNode expr = expr(lexer, model);
+            if (expr != null) {
+                model.setWhereClause(expr);
+                tok = optTok(lexer);
+            } else {
+                throw SqlException.$((lexer.lastTokenPosition()), "empty where clause");
+            }
         }
 
         // expect [group by]

core/src/test/java/io/questdb/griffin/AsOfJoinTest.java

@@ -37,7 +37,7 @@ public class AsOfJoinTest extends AbstractGriffinTest {
     }
 
     @Test
-    public void testAsofJoinFOrSelectWithoutTimestamp() throws Exception {
+    public void testAsofJoinForSelectWithoutTimestamp() throws Exception {
         final String expected = "tag\thi\tlo\n" +
                 "AA\t315515118\t315515118\n" +
                 "BB\t-727724771\t-727724771\n" +
@@ -101,4 +101,56 @@ public class AsOfJoinTest extends AbstractGriffinTest {
                 false
         );
     }
+
+    @Test
+    public void testAsofJoinForSelectWithoutTimestampAndWithWhereStatement() throws Exception {
+        final String expected = "tag\thi\tlo\n" +
+                "AA\t315515118\t315515118\n" +
+                "BB\t-727724771\t-727724771\n" +
+                "CC\t-948263339\t-948263339\n" +
+                "CC\t592859671\t592859671\n" +
+                "AA\t-847531048\t-847531048\n" +
+                "BB\t-2041844972\t-2041844972\n" +
+                "BB\t-1575378703\t-1575378703\n" +
+                "BB\t1545253512\t1545253512\n" +
+                "AA\t1573662097\t1573662097\n" +
+                "AA\t339631474\t339631474\n";
+        assertQuery(
+                "tag\thi\tlo\n",
+                "(select a.tag, a.seq hi, b.seq lo from tab a asof join tab b on (tag)) where hi > lo + 1",
+                "create table tab (\n" +
+                        "    tag symbol index,\n" +
+                        "    seq int,\n" +
+                        "    ts timestamp\n" +
+                        ") timestamp(ts) partition by DAY",
+                null,
+                "insert into tab select * from (select rnd_symbol('AA', 'BB', 'CC') tag, \n" +
+                        "        rnd_int() seq, \n" +
+                        "        timestamp_sequence(172800000000, 360000000) ts \n" +
+                        "    from long_sequence(10)) timestamp (ts)",
+                expected,
+                false
+        );
+    }
+
+    @Test
+    public void testAsofJoinForSelectWithoutTimestampAndWithWhereStatementV2() throws Exception {
+        final String expected = "tag\thi\tlo\n";
+        assertQuery(
+                "tag\thi\tlo\n",
+                "select a.tag, a.seq hi, b.seq lo from tab a asof join tab b on (tag) where b.seq < a.seq",
+                "create table tab (\n" +
+                        "    tag symbol index,\n" +
+                        "    seq int,\n" +
+                        "    ts timestamp\n" +
+                        ") timestamp(ts) partition by DAY",
+                null,
+                "insert into tab select * from (select rnd_symbol('AA', 'BB', 'CC') tag, \n" +
+                        "        rnd_int() seq, \n" +
+                        "        timestamp_sequence(172800000000, 360000000) ts \n" +
+                        "    from long_sequence(10)) timestamp (ts)",
+                expected,
+                false
+        );
+    }
 }

core/src/test/java/io/questdb/griffin/SqlParserTest.java

@@ -4863,6 +4863,36 @@ public class SqlParserTest extends AbstractGriffinTest {
         );
     }
 
+    @Test
+    public void testFilterPostJoin() throws SqlException {
+        assertQuery(
+                "select-choose a.tag tag, a.seq hi, b.seq lo from (select [tag, seq] from tab a asof join select [seq, tag] from tab b on b.tag = a.tag post-join-where b.seq < a.seq)",
+                "select a.tag, a.seq hi, b.seq lo from tab a asof join tab b on (tag) where b.seq < a.seq",
+                modelOf("tab").col("tag", ColumnType.STRING).col("seq", ColumnType.LONG)
+        );
+    }
+    @Test
+    public void testFilterPostJoinSubQuery() throws SqlException {
+        assertQuery(
+                "select-choose tag, hi, lo from ((select-choose [a.tag tag, a.seq hi, b.seq lo] a.tag tag, a.seq hi, b.seq lo from (select [tag, seq] from tab a asof join select [seq, tag] from tab b on b.tag = a.tag)) _xQdbA1)",
+                "(select a.tag, a.seq hi, b.seq lo from tab a asof join tab b on (tag)) where hi > lo + 1",
+                modelOf("tab").col("tag", ColumnType.STRING).col("seq", ColumnType.LONG)
+        );
+    }
+
+    @Test
+    public void testEmptyWhere() throws Exception {
+        assertFailure(
+                "(select a.tag, a.seq hi, b.seq lo from tab a asof join tab b on (tag)) where",
+                "create table tab (\n" +
+                        "    tag string,\n" +
+                        "    seq long\n" +
+                        ")  partition by NONE",
+                71,
+                "empty where clause"
+        );
+    }
+
     private static void assertSyntaxError(
             SqlCompiler compiler,
             String query,