From 6bbe6c9a591f379c62c5052d445b59e7aaea2219 Mon Sep 17 00:00:00 2001
From: Jibing-Li <64681310+Jibing-Li@users.noreply.github.com>
Date: Wed, 21 Feb 2024 19:15:00 +0800
Subject: [PATCH] [fix](statistics)Release StmtExecutor in AnalysisTask object
 when sql execution finished to release memory. #31212

---
 .../apache/doris/statistics/BaseAnalysisTask.java  |  2 ++
 .../apache/doris/statistics/OlapAnalysisTask.java  | 14 ++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/statistics/BaseAnalysisTask.java b/fe/fe-core/src/main/java/org/apache/doris/statistics/BaseAnalysisTask.java
index 789ae0b563..6876784350 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/statistics/BaseAnalysisTask.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/statistics/BaseAnalysisTask.java
@@ -317,6 +317,8 @@ public abstract class BaseAnalysisTask {
                 LOG.debug("End cost time in millisec: " + (System.currentTimeMillis() - startTime)
                         + " Analyze SQL: " + sql + " QueryId: " + queryId);
             }
+            // Release the reference to stmtExecutor, reduce memory usage.
+            stmtExecutor = null;
         }
     }
 
diff --git a/fe/fe-core/src/main/java/org/apache/doris/statistics/OlapAnalysisTask.java b/fe/fe-core/src/main/java/org/apache/doris/statistics/OlapAnalysisTask.java
index a7e2f1f427..5a1d5829c8 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/statistics/OlapAnalysisTask.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/statistics/OlapAnalysisTask.java
@@ -26,6 +26,7 @@ import org.apache.doris.catalog.OlapTable;
 import org.apache.doris.catalog.Partition;
 import org.apache.doris.common.FeConstants;
 import org.apache.doris.common.Pair;
+import org.apache.doris.common.util.DebugUtil;
 import org.apache.doris.qe.AutoCloseConnectContext;
 import org.apache.doris.qe.StmtExecutor;
 import org.apache.doris.statistics.AnalysisInfo.JobType;
@@ -183,14 +184,23 @@ public class OlapAnalysisTask extends BaseAnalysisTask {
                     tbl.getName(), col.getName());
             return null;
         }
+        long startTime = System.currentTimeMillis();
         Map<String, String> params = new HashMap<>();
         params.put("dbName", db.getFullName());
         params.put("colName", StatisticsUtil.escapeColumnName(info.colName));
         params.put("tblName", tbl.getName());
         params.put("index", getIndex());
         StringSubstitutor stringSubstitutor = new StringSubstitutor(params);
-        stmtExecutor = new StmtExecutor(context.connectContext, stringSubstitutor.replace(BASIC_STATS_TEMPLATE));
-        return stmtExecutor.executeInternalQuery().get(0);
+        String sql = stringSubstitutor.replace(BASIC_STATS_TEMPLATE);
+        stmtExecutor = new StmtExecutor(context.connectContext, sql);
+        ResultRow resultRow = stmtExecutor.executeInternalQuery().get(0);
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("Cost time in millisec: " + (System.currentTimeMillis() - startTime)
+                    + " Min max SQL: " + sql + " QueryId: " + DebugUtil.printId(stmtExecutor.getContext().queryId()));
+        }
+        // Release the reference to stmtExecutor, reduce memory usage.
+        stmtExecutor = null;
+        return resultRow;
     }
 
     /**