[Bug] Do not push down limit operation when ODBC table do not push all conjunct as filter.

be/src/exec/odbc_scan_node.cpp

@@ -141,6 +141,11 @@ Status OdbcScanNode::get_next(RuntimeState* state, RowBatch* row_batch, bool* eo
     SCOPED_TIMER(_runtime_profile->total_time_counter());
     SCOPED_TIMER(materialize_tuple_timer());
 
+    if (reached_limit()) {
+        *eos = true;
+        return Status::OK();
+    }
+
     // create new tuple buffer for row_batch
     int tuple_buffer_size = row_batch->capacity() * _tuple_desc->byte_size();
     void* tuple_buffer = _tuple_pool->allocate(tuple_buffer_size);
@@ -156,10 +161,11 @@ Status OdbcScanNode::get_next(RuntimeState* state, RowBatch* row_batch, bool* eo
     while (true) {
         RETURN_IF_CANCELLED(state);
 
-        if (row_batch->is_full()) {
+        if (reached_limit() || row_batch->is_full()) {
             // hang on to last allocated chunk in pool, we'll keep writing into it in the
             // next get_next() call
             row_batch->tuple_data_pool()->acquire_data(_tuple_pool.get(), !reached_limit());
+            *eos = reached_limit();
             return Status::OK();
         }
 

fe/fe-core/src/main/java/org/apache/doris/planner/OdbcScanNode.java

@@ -64,7 +64,7 @@ private static String databaseProperName(TOdbcTableType tableType, String name)
 
     // Now some database have different function call like doris, now doris do not
     // push down the function call except MYSQL
-    private static boolean needPushDown(TOdbcTableType tableType, Expr expr) {
+    private static boolean shouldPushDownConjunct(TOdbcTableType tableType, Expr expr) {
         if (!tableType.equals(TOdbcTableType.MYSQL)) {
             List<FunctionCallExpr> fnExprList = Lists.newArrayList();
             expr.collect(FunctionCallExpr.class, fnExprList);
@@ -114,16 +114,22 @@ protected String getNodeExplainString(String prefix, TExplainLevel detailLevel)
         return output.toString();
     }
 
+    // only all conjuncts be pushed down as filter, we can
+    // push down limit operation to ODBC table
+    private boolean shouldPushDownLimit() {
+        return limit != -1 && conjuncts.isEmpty();
+    }
+
     private String getOdbcQueryStr() {
         StringBuilder sql = new StringBuilder("SELECT ");
 
         // Oracle use the where clause to do top n
-        if (limit != -1 && odbcType == TOdbcTableType.ORACLE) {
+        if (shouldPushDownLimit() && odbcType == TOdbcTableType.ORACLE) {
             filters.add("ROWNUM <= " + limit);
         }
 
         // MSSQL use select top to do top n
-        if (limit != -1 && odbcType == TOdbcTableType.SQLSERVER) {
+        if (shouldPushDownLimit() && odbcType == TOdbcTableType.SQLSERVER) {
             sql.append("TOP " + limit + " ");
         }
 
@@ -137,7 +143,7 @@ private String getOdbcQueryStr() {
         }
 
         // Other DataBase use limit do top n
-        if (limit != -1 && (odbcType == TOdbcTableType.MYSQL || odbcType == TOdbcTableType.POSTGRESQL || odbcType == TOdbcTableType.MONGODB) ) {
+        if (shouldPushDownLimit() && (odbcType == TOdbcTableType.MYSQL || odbcType == TOdbcTableType.POSTGRESQL || odbcType == TOdbcTableType.MONGODB) ) {
             sql.append(" LIMIT " + limit);
         }
 
@@ -175,7 +181,7 @@ private void createOdbcFilters(Analyzer analyzer) {
         }
         ArrayList<Expr> odbcConjuncts = Expr.cloneList(conjuncts, sMap);
         for (Expr p : odbcConjuncts) {
-            if (needPushDown(odbcType, p)) {
+            if (shouldPushDownConjunct(odbcType, p)) {
                 String filter = p.toMySql();
                 filters.add(filter);
                 conjuncts.remove(p);

fe/fe-core/src/test/java/org/apache/doris/planner/QueryPlanTest.java

@@ -1223,9 +1223,16 @@ public void testLimitOfExternalTable() throws Exception {
         String explainString = UtFrameUtils.getSQLPlanOrErrorMsg(connectContext, queryStr);
         Assert.assertTrue(explainString.contains("LIMIT 10"));
 
-        // ODBC table (Oracle)
+        // ODBC table (Oracle) not push down limit
         queryStr = "explain select * from odbc_oracle where k1 > 10 and abs(k1) > 10 limit 10";
         explainString = UtFrameUtils.getSQLPlanOrErrorMsg(connectContext, queryStr);
+        // abs is function, so Doris do not push down function except MySQL Database
+        // so should not push down limit operation
+        Assert.assertTrue(!explainString.contains("ROWNUM <= 10"));
+
+        // ODBC table (Oracle) push down limit
+        queryStr = "explain select * from odbc_oracle where k1 > 10 limit 10";
+        explainString = UtFrameUtils.getSQLPlanOrErrorMsg(connectContext, queryStr);
         Assert.assertTrue(explainString.contains("ROWNUM <= 10"));
 
         // MySQL table