diff --git a/src/gausskernel/storage/replication/logical/parallel_reorderbuffer.cpp b/src/gausskernel/storage/replication/logical/parallel_reorderbuffer.cpp
index 3991af570..9e82a7d1a 100644
--- a/src/gausskernel/storage/replication/logical/parallel_reorderbuffer.cpp
+++ b/src/gausskernel/storage/replication/logical/parallel_reorderbuffer.cpp
@@ -80,12 +80,14 @@ static void ParallelReorderBufferRestoreChange(ParallelReorderBuffer *rb, Parall
 /* Parallel decoding batch sending unit length is set to 1MB. */
 static const int g_batch_unit_length = 1 * 1024 * 1024;
 
+/* Parallel decoding caches at most 512 transactions. */
+static const Size g_max_cached_txns = 512;
+
 void ParallelReorderBufferQueueChange(ParallelReorderBuffer *rb, logicalLog *change, int slotId)
 {
     ParallelReorderBufferTXN *txn = NULL;
     txn = ParallelReorderBufferTXNByXid(rb, change->xid, true, NULL, change->lsn, true);
 
-    Assert(InvalidXLogRecPtr != change->lsn);
     dlist_push_tail(&txn->changes, &change->node);
     txn->nentries++;
     txn->nentries_mem++;
@@ -238,7 +240,13 @@ ParallelReorderBufferTXN *ParallelReorderBufferGetTXN(ParallelReorderBuffer *rb)
     ParallelReorderBufferTXN *txn = NULL;
     int rc = 0;
     /* check the slab cache */
-    txn = (ParallelReorderBufferTXN *)palloc(sizeof(ParallelReorderBufferTXN));
+    if (rb->nr_cached_transactions > 0) {
+        rb->nr_cached_transactions--;
+        txn = (ParallelReorderBufferTXN *)dlist_container(ParallelReorderBufferTXN, node,
+                                                  dlist_pop_head_node(&rb->cached_transactions));
+    } else {
+        txn = (ParallelReorderBufferTXN *)palloc(sizeof(ParallelReorderBufferTXN));
+    }
 
     rc = memset_s(txn, sizeof(ParallelReorderBufferTXN), 0, sizeof(ParallelReorderBufferTXN));
     securec_check(rc, "", "");
@@ -249,6 +257,7 @@ ParallelReorderBufferTXN *ParallelReorderBufferGetTXN(ParallelReorderBuffer *rb)
 
     return txn;
 }
+
 void ParallelReorderBufferReturnTXN(ParallelReorderBuffer *rb, ParallelReorderBufferTXN *txn)
 {
     /* clean the lookup cache if we were cached (quite likely) */
@@ -270,6 +279,13 @@ void ParallelReorderBufferReturnTXN(ParallelReorderBuffer *rb, ParallelReorderBu
 
     txn->nentries = 0;
     txn->nentries_mem = 0;
+    /* check whether to put into the slab cache */
+    if (rb->nr_cached_transactions < g_max_cached_txns) {
+        rb->nr_cached_transactions++;
+        dlist_push_head(&rb->cached_transactions, &txn->node);
+    } else {
+        pfree(txn);
+    }
 }
 /* ---------------------------------------
  * toast reassembly support
@@ -1163,6 +1179,9 @@ static logicalLog *ParallelReorderBufferIterTXNNext(ParallelReorderBuffer *rb,
     entry = &state->entries[off];
 
     if (!dlist_is_empty(&state->old_change)) {
+        change = dlist_container(logicalLog, node,  dlist_pop_head_node(&state->old_change));
+        FreeLogicalLog(change, slotId);
+        /* We should find atmost one old_change here */
         Assert(dlist_is_empty(&state->old_change));
     }
 
@@ -1219,6 +1238,29 @@ static logicalLog *ParallelReorderBufferIterTXNNext(ParallelReorderBuffer *rb,
     return change;
 }
 
+/*
+ * Deallocate the iterator
+ */
+static void ParallelReorderBufferIterTXNFinish(ParallelReorderBufferIterTXNState *state, int slotId)
+{
+    for (Size off = 0; off < state->nr_txns; off++) {
+        if (state->entries[off].fd != -1) {
+            (void)CloseTransientFile(state->entries[off].fd);
+        }
+    }
+
+    /* free memory we might have "leaked" in the last *Next call */
+    if (!dlist_is_empty(&state->old_change)) {
+        logicalLog *change = NULL;
+        change = dlist_container(logicalLog, node, dlist_pop_head_node(&state->old_change));
+        FreeLogicalLog(change, slotId);
+        Assert(dlist_is_empty(&state->old_change));
+    }
+
+    binaryheap_free(state->heap);
+    pfree(state);
+}
+
 /*
  * Forget the contents of a transaction if we aren't interested in it's
  * contents. Needs to be first called for subtransactions and then for the
@@ -1237,6 +1279,7 @@ void ParallelReorderBufferForget(ParallelReorderBuffer *rb, int slotId, Parallel
         FreeLogicalLog(logChange, slotId);
     }
     ParallelReorderBufferCleanupTXN(rb, txn);
+    ParallelReorderBufferIterTXNFinish(iterstate, slotId);
 }
 
 /*
@@ -1440,6 +1483,7 @@ void ParallelReorderBufferCommit(ParallelReorderBuffer *rb, logicalLog *change,
             g_Logicaldispatcher[slotId].pOptions.sending_batch > 0);
     }
     ParallelReorderBufferCleanupTXN(rb, txn);
+    ParallelReorderBufferIterTXNFinish(iterstate, slotId);
 
     ParallelCheckBatch(ctx->out, pdata, slotId, &oldCtx,
         (pdata->pOptions.skip_empty_xacts && !pdata->pOptions.xact_wrote_changes));
@@ -1545,12 +1589,14 @@ ParallelReorderBuffer *ParallelReorderBufferAllocate(int slotId)
     hash_ctl.hcxt = buffer->context;
 
     const long reorderBufferNelem = 1000;
-    buffer->by_txn = hash_create("ReorderBufferByXid", reorderBufferNelem,
+    buffer->by_txn = hash_create("ParallelReorderBufferByXid", reorderBufferNelem,
         &hash_ctl, HASH_ELEM | HASH_FUNCTION | HASH_CONTEXT);
 
     buffer->by_txn_last_xid = InvalidTransactionId;
     buffer->by_txn_last_txn = NULL;
 
+    buffer->nr_cached_transactions = 0;
+    buffer->nr_cached_tuplebufs = 0;
     buffer->nr_cached_changes = 0;
 
     buffer->current_restart_decoding_lsn = InvalidXLogRecPtr;
diff --git a/src/include/replication/parallel_reorderbuffer.h b/src/include/replication/parallel_reorderbuffer.h
index 3a69b3b20..866b53cf5 100644
--- a/src/include/replication/parallel_reorderbuffer.h
+++ b/src/include/replication/parallel_reorderbuffer.h
@@ -340,12 +340,15 @@ struct ParallelReorderBuffer {
      * ontop of reorderbuffer.c
      */
 
+    /* cached ParallelReorderBufferTXNs */
+    dlist_head cached_transactions;
+    Size nr_cached_transactions;
 
-    /* cached ReorderBufferChanges */
+    /* cached ParallelReorderBufferChanges */
     dlist_head cached_changes;
     Size nr_cached_changes;
 
-    /* cached ReorderBufferTupleBufs */
+    /* cached ParallelReorderBufferTupleBufs */
     slist_head cached_tuplebufs;
     Size nr_cached_tuplebufs;
     TransactionId lastRunningXactOldestXmin;