diff --git a/tests/buffer/sql_test.py b/tests/buffer/sql_test.py
index 4d63f041e4..a1a9f39907 100644
--- a/tests/buffer/sql_test.py
+++ b/tests/buffer/sql_test.py
@@ -1,4 +1,5 @@
 import os
+from copy import deepcopy
 
 import ray
 import torch
@@ -40,7 +41,11 @@ async def test_sql_exp_buffer_read_write(self, enable_replay: bool) -> None:
         )
         if enable_replay:
             config.replay_buffer = ReplayBufferConfig(enable=True)
-        sql_writer = SQLWriter(config.to_storage_config())
+        writer_config = deepcopy(config)
+        writer_config.batch_size = put_batch_size
+        # Create buffer by writer, so buffer.batch_size will be set to put_batch_size
+        # This will check whether read_batch_size tasks effect
+        sql_writer = SQLWriter(writer_config.to_storage_config())
         sql_reader = SQLReader(config.to_storage_config())
         exps = [
             Experience(
diff --git a/trinity/buffer/reader/queue_reader.py b/trinity/buffer/reader/queue_reader.py
index b3b1d14c12..6f8e7c0334 100644
--- a/trinity/buffer/reader/queue_reader.py
+++ b/trinity/buffer/reader/queue_reader.py
@@ -21,7 +21,7 @@ def __init__(self, config: StorageConfig):
 
     def read(self, batch_size: Optional[int] = None, **kwargs) -> List:
         try:
-            batch_size = batch_size or self.read_batch_size
+            batch_size = self.read_batch_size if batch_size is None else batch_size
             exps = ray.get(self.queue.get_batch.remote(batch_size, timeout=self.timeout, **kwargs))
             if len(exps) != batch_size:
                 raise TimeoutError(
@@ -32,7 +32,7 @@ def read(self, batch_size: Optional[int] = None, **kwargs) -> List:
         return exps
 
     async def read_async(self, batch_size: Optional[int] = None, **kwargs) -> List:
-        batch_size = batch_size or self.read_batch_size
+        batch_size = self.read_batch_size if batch_size is None else batch_size
         exps = await self.queue.get_batch.remote(batch_size, timeout=self.timeout, **kwargs)
         if len(exps) != batch_size:
             raise TimeoutError(
diff --git a/trinity/buffer/reader/sql_reader.py b/trinity/buffer/reader/sql_reader.py
index f7572c628c..fd1425bb8f 100644
--- a/trinity/buffer/reader/sql_reader.py
+++ b/trinity/buffer/reader/sql_reader.py
@@ -16,15 +16,18 @@ class SQLReader(BufferReader):
     def __init__(self, config: StorageConfig) -> None:
         assert config.storage_type == StorageType.SQL.value
         self.wrap_in_ray = config.wrap_in_ray
+        self.read_batch_size = config.batch_size
         self.storage = SQLStorage.get_wrapper(config)
 
     def read(self, batch_size: Optional[int] = None, **kwargs) -> List:
+        batch_size = self.read_batch_size if batch_size is None else batch_size
         if self.wrap_in_ray:
             return ray.get(self.storage.read.remote(batch_size, **kwargs))
         else:
             return self.storage.read(batch_size, **kwargs)
 
     async def read_async(self, batch_size: Optional[int] = None, **kwargs) -> List:
+        batch_size = self.read_batch_size if batch_size is None else batch_size
         if self.wrap_in_ray:
             try:
                 return await self.storage.read.remote(batch_size, **kwargs)
diff --git a/trinity/buffer/storage/sql.py b/trinity/buffer/storage/sql.py
index 04f0c20bda..eb1097cdc7 100644
--- a/trinity/buffer/storage/sql.py
+++ b/trinity/buffer/storage/sql.py
@@ -197,7 +197,7 @@ def read(self, batch_size: Optional[int] = None, **kwargs) -> List[Experience]:
         if self.stopped:
             raise StopIteration()
 
-        batch_size = batch_size or self.batch_size
+        batch_size = self.batch_size if batch_size is None else batch_size
         return self._read_method(batch_size, **kwargs)
 
     @classmethod
@@ -248,7 +248,7 @@ def read(self, batch_size: Optional[int] = None) -> List[Task]:
             raise StopIteration()
         if self.offset > self.total_samples:
             raise StopIteration()
-        batch_size = batch_size or self.batch_size
+        batch_size = self.batch_size if batch_size is None else batch_size
         with retry_session(self.session, self.max_retry_times, self.max_retry_interval) as session:
             query = (
                 session.query(self.table_model_cls)