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

…e#41563) (apache#41712)

Because Oracle versions below Oracle21 do not support null as an
operator, and considering that most users' Oracle versions are below
Oracle21, we disable Oracle's null operator pushdown by default.
pick (apache#41563)

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;
@@ -297,6 +298,13 @@ 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)) {
@@ -362,4 +370,10 @@ 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

@@ -481,6 +481,8 @@ 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";
 
@@ -654,6 +656,11 @@ 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 = {"是否允许将 NULL 谓词下推到 Oracle JDBC 外部表。",
+                    "Whether to allow NULL predicates to be pushed down to Oracle JDBC external tables."})
+    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; """
+
     }
 }