diff --git a/dbcon/mysql/is_columnstore_files.cpp b/dbcon/mysql/is_columnstore_files.cpp
index 11f64e1d2..060f9d280 100644
--- a/dbcon/mysql/is_columnstore_files.cpp
+++ b/dbcon/mysql/is_columnstore_files.cpp
@@ -33,6 +33,7 @@
 #include "we_brm.h"
 #include "bytestream.h"
 #include "liboamcpp.h"
+#include "oamcache.h"
 #include "messagequeue.h"
 #include "messagequeuepool.h"
 #include "we_messages.h"
@@ -119,7 +120,7 @@ static int generate_result(BRM::OID_t oid, BRM::DBRM* emp, TABLE* table, THD* th
   off_t compressedFileSize = 0;
   we_config.initConfigCache();
   messageqcpp::MessageQueueClient* msgQueueClient;
-  oam::Oam oam_instance;
+  oam::OamCache* oamcache = oam::OamCache::makeOamCache();
   int pmId = 0;
   int rc;
 
@@ -141,7 +142,7 @@ static int generate_result(BRM::OID_t oid, BRM::DBRM* emp, TABLE* table, THD* th
 
     try
     {
-      oam_instance.getDbrootPmConfig(iter->dbRoot, pmId);
+      pmId = oamcache->getOwnerPM(iter->dbRoot);
     }
     catch (std::runtime_error&)
     {
diff --git a/dmlproc/dmlproc.cpp b/dmlproc/dmlproc.cpp
index 204bb15e3..565a8b35b 100644
--- a/dmlproc/dmlproc.cpp
+++ b/dmlproc/dmlproc.cpp
@@ -393,7 +393,7 @@ void rollbackAll(DBRM* dbrm)
 
       try
       {
-        rollbackProcessor.processBulkRollback(tableLocks[i], dbrm, uniqueId, dbRootPMMap, lockReleased);
+        rollbackProcessor.processBulkRollback(tableLocks[i], dbrm, uniqueId, oamcache, lockReleased);
         ostringstream oss;
         oss << "DMLProc started bulkrollback on table OID " << tableLocks[i].tableOID << " and table lock id "
             << tableLocks[i].id << " finished and tablelock is released.";
diff --git a/dmlproc/dmlprocessor.cpp b/dmlproc/dmlprocessor.cpp
index 46949dbfb..5bc60ad9a 100644
--- a/dmlproc/dmlprocessor.cpp
+++ b/dmlproc/dmlprocessor.cpp
@@ -1847,7 +1847,7 @@ void DMLProcessor::operator()()
 
 void RollbackTransactionProcessor::processBulkRollback(BRM::TableLockInfo lockInfo, BRM::DBRM* dbrm,
                                                        uint64_t uniqueId,
-                                                       OamCache::dbRootPMMap_t& dbRootPMMap,
+                                                       OamCache* oamcache,
                                                        bool& lockReleased)
 {
   // Take over ownership of stale lock.
@@ -1886,7 +1886,7 @@ void RollbackTransactionProcessor::processBulkRollback(BRM::TableLockInfo lockIn
 
   for (uint32_t i = 0; i < lockInfo.dbrootList.size(); i++)
   {
-    pmId = (*dbRootPMMap)[lockInfo.dbrootList[i]];
+    pmId = oamcache->getOwnerPM(lockInfo.dbrootList[i]);
     pmSet.insert(pmId);
   }
 
diff --git a/dmlproc/dmlprocessor.h b/dmlproc/dmlprocessor.h
index 3492bcfa5..6d020770b 100644
--- a/dmlproc/dmlprocessor.h
+++ b/dmlproc/dmlprocessor.h
@@ -321,7 +321,7 @@ class RollbackTransactionProcessor : public dmlpackageprocessor::DMLPackageProce
   }
 
   void processBulkRollback(BRM::TableLockInfo lockInfo, BRM::DBRM* dbrm, uint64_t uniqueId,
-                           oam::OamCache::dbRootPMMap_t& dbRootPMMap, bool& lockReleased);
+                           oam::OamCache* oamcache, bool& lockReleased);
 
  protected:
  private:
diff --git a/oam/oamcpp/oamcache.cpp b/oam/oamcpp/oamcache.cpp
index 5f336c14c..15f50401d 100644
--- a/oam/oamcpp/oamcache.cpp
+++ b/oam/oamcpp/oamcache.cpp
@@ -295,5 +295,17 @@ int OamCache::getOwnerPM(int dbroot) // Owner's PM index.
   }
   idbassert_s(0, "cannot find owner for dbroot " << dbroot);
 }
+std::vector<int> OamCache::getPMDBRoots(int PM) // what DBRoots are owned by given PM.
+{
+  std::vector<int> result;
+  for (const auto& dbroot : (*dbRootPMMap))
+  {
+    if (dbroot.second.find(PM) != dbroot.second.end())
+    {
+      result.push_back(dbroot.first);
+    }
+  }
+  return result;
+}
 
 } /* namespace oam */
diff --git a/tools/cleartablelock/cleartablelock.cpp b/tools/cleartablelock/cleartablelock.cpp
index 361d354a6..5620bbb56 100644
--- a/tools/cleartablelock/cleartablelock.cpp
+++ b/tools/cleartablelock/cleartablelock.cpp
@@ -159,19 +159,22 @@ int constructPMList(const std::vector<uint32_t>& dbRootList, std::vector<uint32_
     // Get OAM information
     oam::Oam oam;
     std::set<uint32_t> pmSet;  // used to filter out duplicates
-    int pm;
+    std::set<int> pms;
 
     for (unsigned j = 0; j < dbRootList.size(); j++)
     {
       dbRoot = dbRootList[j];
-      oam.getDbrootPmConfig(dbRootList[j], pm);
-      pmSet.insert(pm);
+      oam.getDbrootPmConfig(dbRootList[j], pms);
+      for (auto pm : pms)
+      {
+        pmSet.insert(pm);
+      }
     }
 
     // Store unique set of PM IDs into output vector
-    for (std::set<uint32_t>::const_iterator iter = pmSet.begin(); iter != pmSet.end(); ++iter)
+    for (auto pm : pmSet)
     {
-      pmList.push_back(*iter);
+      pmList.push_back(pm);
     }
   }
   catch (std::exception& ex)