From 39ab5e6b119b3cbb2e87da42e38419acc9fab8e2 Mon Sep 17 00:00:00 2001
From: cambyzhu <cambyzhu@tencent.com>
Date: Thu, 7 Mar 2024 13:23:28 +0800
Subject: [PATCH] support select experimental session variable

---
 .../java/org/apache/doris/qe/VariableMgr.java | 26 ++++++++++++-------
 .../nereids_syntax_p0/system_var.groovy       |  5 ++++
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/qe/VariableMgr.java b/fe/fe-core/src/main/java/org/apache/doris/qe/VariableMgr.java
index 93c842f0bfa524..e83fd474dafd73 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/qe/VariableMgr.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/qe/VariableMgr.java
@@ -284,7 +284,10 @@ private static void checkUpdate(SetVar setVar, int flag) throws DdlException {
     //      setVar: variable information that needs to be set
     public static void setVar(SessionVariable sessionVariable, SetVar setVar)
             throws DdlException {
-        VarContext varCtx = setVarPreCheck(setVar);
+        VarContext varCtx = getVarContext(setVar.getVariable());
+        if (varCtx == null) {
+            ErrorReport.reportDdlException(ErrorCode.ERR_UNKNOWN_SYSTEM_VARIABLE, setVar.getVariable());
+        }
         checkUpdate(setVar, varCtx.getFlag());
         setVarInternal(sessionVariable, setVar, varCtx);
     }
@@ -299,7 +302,10 @@ public static void setVar(SessionVariable sessionVariable, SetVar setVar)
     // So in this case, we should just ignore this exception and return.
     public static void setVarForNonMasterFE(SessionVariable sessionVariable, SetVar setVar)
             throws DdlException {
-        VarContext varCtx = setVarPreCheck(setVar);
+        VarContext varCtx = getVarContext(setVar.getVariable());
+        if (varCtx == null) {
+            ErrorReport.reportDdlException(ErrorCode.ERR_UNKNOWN_SYSTEM_VARIABLE, setVar.getVariable());
+        }
         try {
             checkUpdate(setVar, varCtx.getFlag());
         } catch (DdlException e) {
@@ -311,9 +317,9 @@ public static void setVarForNonMasterFE(SessionVariable sessionVariable, SetVar
         setVarInternal(sessionVariable, setVar, varCtx);
     }
 
-    @NotNull
-    private static VarContext setVarPreCheck(SetVar setVar) throws DdlException {
-        String varName = setVar.getVariable();
+    @Nullable
+    private static VarContext getVarContext(String name) {
+        String varName = name;
         boolean hasExpPrefix = false;
         if (varName.startsWith(VariableAnnotation.EXPERIMENTAL.getPrefix())) {
             varName = varName.substring(VariableAnnotation.EXPERIMENTAL.getPrefix().length());
@@ -325,13 +331,13 @@ private static VarContext setVarPreCheck(SetVar setVar) throws DdlException {
         }
         VarContext ctx = ctxByVarName.get(varName);
         if (ctx == null) {
-            ErrorReport.reportDdlException(ErrorCode.ERR_UNKNOWN_SYSTEM_VARIABLE, setVar.getVariable());
+            return null;
         }
         // for non-matched prefix, report an error
         VariableAnnotation varType = ctx.getField().getAnnotation(VarAttr.class).varType();
-        if (hasExpPrefix && (!setVar.getVariable().startsWith(varType.getPrefix())
+        if (hasExpPrefix && (!name.startsWith(varType.getPrefix())
                 || varType == VariableAnnotation.NONE)) {
-            ErrorReport.reportDdlException(ErrorCode.ERR_UNKNOWN_SYSTEM_VARIABLE, setVar.getVariable());
+            return null;
         }
         return ctx;
     }
@@ -533,7 +539,7 @@ public static void replayGlobalVariableV2(GlobalVarPersistInfo info) throws DdlE
 
     // Get variable value through variable name, used to satisfy statement like `SELECT @@comment_version`
     public static void fillValue(SessionVariable var, VariableExpr desc) throws AnalysisException {
-        VarContext ctx = ctxByVarName.get(desc.getName());
+        VarContext ctx = getVarContext(desc.getName());
         if (ctx == null) {
             ErrorReport.reportAnalysisException(ErrorCode.ERR_UNKNOWN_SYSTEM_VARIABLE, desc.getName());
         }
@@ -621,7 +627,7 @@ public static String getValue(SessionVariable var, VariableExpr desc) throws Ana
 
     // For Nereids optimizer
     public static @Nullable Literal getLiteral(SessionVariable var, String name, SetType setType) {
-        VarContext ctx = ctxByVarName.get(name);
+        VarContext ctx = getVarContext(name);
         if (ctx == null) {
             return null;
         }
diff --git a/regression-test/suites/nereids_syntax_p0/system_var.groovy b/regression-test/suites/nereids_syntax_p0/system_var.groovy
index a2ab3bfa9ed22f..242df6ec94e77e 100644
--- a/regression-test/suites/nereids_syntax_p0/system_var.groovy
+++ b/regression-test/suites/nereids_syntax_p0/system_var.groovy
@@ -46,4 +46,9 @@ suite("nereids_sys_var") {
         sql "select @@session.enable_nereids_planner"
         result ([[true]])
     }
+
+    test {
+        sql "select @@session.experimental_enable_nereids_planner"
+        result ([[true]])
+    }
 }