In the multi-threaded mode, updating the column selectivity ("analyze") in the…

In the multi-threaded mode, updating the column selectivity ("analyze") in the background sometimes did not work.

h2/src/main/org/h2/command/ddl/Analyze.java

@@ -122,6 +122,7 @@ public class Analyze extends DefineCommand {
                 // (which is the case if we are within a trigger)
                 // then we can't update the statistics because
                 // that would unlock all locked objects
+                synchronized (sysSession) {
                     synchronized (db) {
                         db.updateMeta(sysSession, table);
                         sysSession.commit(true);
@@ -129,6 +130,7 @@ public class Analyze extends DefineCommand {
                 }
             }
         }
+    }
 
     public void setTop(int top) {
         this.sampleRows = top;

h2/src/main/org/h2/command/dml/Set.java

@@ -107,9 +107,12 @@ public class Set extends Prepared {
             database.setCluster(value);
             // use the system session so that the current transaction
             // (if any) is not committed
+            Session sysSession = database.getSystemSession();
+            synchronized (sysSession) {
                 synchronized (database) {
-                addOrUpdateSetting(database.getSystemSession(), name, value, 0);
-                database.getSystemSession().commit(true);
+                    addOrUpdateSetting(sysSession, name, value, 0);
+                    sysSession.commit(true);
+                }
             }
             break;
         }