[fix](jdbc catalog) Disable oracle scan null operator pushdown

fe/fe-core/src/main/java/org/apache/doris/datasource/jdbc/source/JdbcScanNode.java

@@ -24,6 +24,7 @@
 import org.apache.doris.analysis.Expr;
 import org.apache.doris.analysis.ExprSubstitutionMap;
 import org.apache.doris.analysis.FunctionCallExpr;
+import org.apache.doris.analysis.NullLiteral;
 import org.apache.doris.analysis.SlotDescriptor;
 import org.apache.doris.analysis.SlotRef;
 import org.apache.doris.analysis.TupleDescriptor;
@@ -304,6 +305,13 @@ public StatsDelta genStatsDelta() throws AnalysisException {
     }
 
     private static boolean shouldPushDownConjunct(TOdbcTableType tableType, Expr expr) {
+        // Prevent pushing down expressions with NullLiteral to Oracle
+        if (ConnectContext.get() != null
+                && !ConnectContext.get().getSessionVariable().jdbcOracleNullPredicatePushdown
+                && containsNullLiteral(expr)
+                && tableType.equals(TOdbcTableType.ORACLE)) {
+            return false;
+        }
         if (containsFunctionCallExpr(expr)) {
             if (tableType.equals(TOdbcTableType.MYSQL) || tableType.equals(TOdbcTableType.CLICKHOUSE)
                     || tableType.equals(TOdbcTableType.ORACLE)) {
@@ -369,4 +377,10 @@ private static String handleTrinoDateFormat(Expr expr, TableIf tbl) {
         }
         return expr.toExternalSql(TableType.JDBC_EXTERNAL_TABLE, tbl);
     }
+
+    private static boolean containsNullLiteral(Expr expr) {
+        List<NullLiteral> nullExprList = Lists.newArrayList();
+        expr.collect(NullLiteral.class, nullExprList);
+        return !nullExprList.isEmpty();
+    }
 }

fe/fe-core/src/main/java/org/apache/doris/qe/SessionVariable.java

@@ -504,6 +504,8 @@ public class SessionVariable implements Serializable, Writable {
 
     public static final String JDBC_CLICKHOUSE_QUERY_FINAL = "jdbc_clickhouse_query_final";
 
+    public static final String JDBC_ORACLE_NULL_PREDICATE_PUSHDOWN = "jdbc_oracle_null_predicate_pushdown";
+
     public static final String ENABLE_MEMTABLE_ON_SINK_NODE =
             "enable_memtable_on_sink_node";
 
@@ -688,6 +690,12 @@ public class SessionVariable implements Serializable, Writable {
                     "Whether to add the FINAL keyword to the query SQL when querying ClickHouse JDBC external tables."})
     public boolean jdbcClickhouseQueryFinal = false;
 
+    @VariableMgr.VarAttr(name = JDBC_ORACLE_NULL_PREDICATE_PUSHDOWN, needForward = true,
+            description = {"是否启用 Oracle JDBC 外部表时，Scan 节点的 NULL 谓词下推。",
+                    "Whether to enable NULL predicate pushdown for the Scan node "
+                            + "when Oracle JDBC external tables are enabled."})
+    public boolean jdbcOracleNullPredicatePushdown = false;
+
     @VariableMgr.VarAttr(name = ROUND_PRECISE_DECIMALV2_VALUE)
     public boolean roundPreciseDecimalV2Value = false;
 

regression-test/data/external_table_p0/jdbc/test_oracle_jdbc_catalog.out

@@ -269,3 +269,38 @@ doris
 1	111	123	7456123.89	573	34	673.43	34.1264	60.0	23.231	99	9999	999999999	999999999999999999	999	99999	9999999999	9999999999999999999	1	china 	beijing	alice	abcdefghrjkmnopq	123.45	12300	0.0012345	2022-01-21T05:23:01	2019-11-12T20:33:57.999	2019-11-12T20:33:57.999998	2019-11-12T20:33:57.999996	2019-11-12T20:33:57.999997	223-9	12 10:23:1.123457000
 2	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N	\N
 
+-- !null_operator1 --
+1	alice	20	99.5
+2	bob	21	90.5
+3	jerry	23	88.0
+4	andy	21	93.0
+
+-- !null_operator2 --
+2	bob	21	90.5
+3	jerry	23	88.0
+4	andy	21	93.0
+
+-- !null_operator3 --
+1	alice	20	99.5
+
+-- !null_operator4 --
+
+-- !null_operator5 --
+
+-- !null_operator6 --
+
+-- !null_operator7 --
+3	jerry	23	88.0
+
+-- !null_operator8 --
+1	alice	20	99.5
+4	andy	21	93.0
+
+-- !null_operator9 --
+
+-- !null_operator10 --
+1	alice	20	99.5
+2	bob	21	90.5
+3	jerry	23	88.0
+4	andy	21	93.0
+

regression-test/suites/external_table_p0/jdbc/test_oracle_jdbc_catalog.groovy

@@ -297,5 +297,31 @@ suite("test_oracle_jdbc_catalog", "p0,external,oracle,external_docker,external_d
         qt_query_ojdbc6_all_types """ select * from oracle_ojdbc6.DORIS_TEST.TEST_ALL_TYPES order by 1; """
 
         sql """drop catalog if exists oracle_ojdbc6; """
+
+        // test oracle null operator
+        sql """ drop catalog if exists oracle_null_operator; """
+        sql """ create catalog if not exists oracle_null_operator properties(
+                    "type"="jdbc",
+                    "user"="doris_test",
+                    "password"="123456",
+                    "jdbc_url" = "jdbc:oracle:thin:@${externalEnvIp}:${oracle_port}:${SID}",
+                    "driver_url" = "${driver_url}",
+                    "driver_class" = "oracle.jdbc.driver.OracleDriver"
+        );"""
+
+        sql """ use oracle_null_operator.DORIS_TEST; """
+        order_qt_null_operator1 """ SELECT * FROM STUDENT WHERE (id IS NOT NULL OR NULL); """
+        order_qt_null_operator2 """ SELECT * FROM STUDENT WHERE (age > 20 OR NULL); """
+        order_qt_null_operator3 """ SELECT * FROM STUDENT WHERE (name = 'alice' AND age = 20); """
+        order_qt_null_operator4 """ SELECT * FROM STUDENT WHERE (LENGTH(name) > 3 AND NULL); """
+        order_qt_null_operator5 """ SELECT * FROM STUDENT WHERE (age = NULL); """
+        order_qt_null_operator6 """ SELECT * FROM STUDENT WHERE (score IS NULL); """
+        order_qt_null_operator7 """ SELECT * FROM STUDENT WHERE ((age > 20 AND score < 90) OR NULL); """
+        order_qt_null_operator8 """ SELECT * FROM STUDENT WHERE (age BETWEEN 20 AND 25) AND (name LIKE 'a%'); """
+        order_qt_null_operator9 """ SELECT * FROM STUDENT WHERE (id IS NOT NULL AND NULL); """
+        order_qt_null_operator10 """ SELECT * FROM STUDENT WHERE (name IS NULL OR age IS NOT NULL); """
+
+        sql """ drop catalog if exists oracle_null_operator; """
+
     }
 }