diff --git a/src/DataStreams/PostgreSQLBlockInputStream.cpp b/src/DataStreams/PostgreSQLBlockInputStream.cpp
index 7e9aa40e904..495d08fc831 100644
--- a/src/DataStreams/PostgreSQLBlockInputStream.cpp
+++ b/src/DataStreams/PostgreSQLBlockInputStream.cpp
@@ -23,25 +23,9 @@ namespace DB
 {
 
 
-template<>
-PostgreSQLBlockInputStream<pqxx::read_transaction>::PostgreSQLBlockInputStream(
-    std::shared_ptr<pqxx::read_transaction> tx_,
-    const std::string & query_str_,
-    const Block & sample_block,
-    const UInt64 max_block_size_,
-    bool auto_commit_)
-    : query_str(query_str_)
-    , max_block_size(max_block_size_)
-    , auto_commit(auto_commit_)
-    , tx(tx_)
-{
-    description.init(sample_block);
-}
-
-
-template<>
-PostgreSQLBlockInputStream<pqxx::work>::PostgreSQLBlockInputStream(
-    std::shared_ptr<pqxx::work> tx_,
+template<typename T>
+PostgreSQLBlockInputStream<T>::PostgreSQLBlockInputStream(
+    std::shared_ptr<T> tx_,
     const std::string & query_str_,
     const Block & sample_block,
     const UInt64 max_block_size_,
@@ -138,6 +122,12 @@ void PostgreSQLBlockInputStream<T>::readSuffix()
     }
 }
 
+template
+class PostgreSQLBlockInputStream<pqxx::work>;
+
+template
+class PostgreSQLBlockInputStream<pqxx::read_transaction>;
+
 }
 
 #endif
diff --git a/src/Dictionaries/PostgreSQLDictionarySource.cpp b/src/Dictionaries/PostgreSQLDictionarySource.cpp
index 954e5f4e187..5c660f1a5f5 100644
--- a/src/Dictionaries/PostgreSQLDictionarySource.cpp
+++ b/src/Dictionaries/PostgreSQLDictionarySource.cpp
@@ -68,8 +68,7 @@ PostgreSQLDictionarySource::PostgreSQLDictionarySource(const PostgreSQLDictionar
 BlockInputStreamPtr PostgreSQLDictionarySource::loadAll()
 {
     LOG_TRACE(log, load_all_query);
-    auto tx = std::make_shared<pqxx::read_transaction>(*connection->conn());
-    return std::make_shared<PostgreSQLBlockInputStream<pqxx::read_transaction>>(tx, load_all_query, sample_block, max_block_size);
+    return loadBase(load_all_query);
 }
 
 
@@ -77,21 +76,25 @@ BlockInputStreamPtr PostgreSQLDictionarySource::loadUpdatedAll()
 {
     auto load_update_query = getUpdateFieldAndDate();
     LOG_TRACE(log, load_update_query);
-    auto tx = std::make_shared<pqxx::read_transaction>(*connection->conn());
-    return std::make_shared<PostgreSQLBlockInputStream<pqxx::read_transaction>>(tx, load_update_query, sample_block, max_block_size);
+    return loadBase(load_update_query);
 }
 
 BlockInputStreamPtr PostgreSQLDictionarySource::loadIds(const std::vector<UInt64> & ids)
 {
     const auto query = query_builder.composeLoadIdsQuery(ids);
-    auto tx = std::make_shared<pqxx::read_transaction>(*connection->conn());
-    return std::make_shared<PostgreSQLBlockInputStream<pqxx::read_transaction>>(tx, query, sample_block, max_block_size);
+    return loadBase(query);
 }
 
 
 BlockInputStreamPtr PostgreSQLDictionarySource::loadKeys(const Columns & key_columns, const std::vector<size_t> & requested_rows)
 {
     const auto query = query_builder.composeLoadKeysQuery(key_columns, requested_rows, ExternalQueryBuilder::AND_OR_CHAIN);
+    return loadBase(query);
+}
+
+
+BlockInputStreamPtr PostgreSQLDictionarySource::loadBase(const String & query)
+{
     auto tx = std::make_shared<pqxx::read_transaction>(*connection->conn());
     return std::make_shared<PostgreSQLBlockInputStream<pqxx::read_transaction>>(tx, query, sample_block, max_block_size);
 }
diff --git a/src/Dictionaries/PostgreSQLDictionarySource.h b/src/Dictionaries/PostgreSQLDictionarySource.h
index a826ff15f4f..f3d6fc15e05 100644
--- a/src/Dictionaries/PostgreSQLDictionarySource.h
+++ b/src/Dictionaries/PostgreSQLDictionarySource.h
@@ -37,6 +37,7 @@ public:
     BlockInputStreamPtr loadUpdatedAll() override;
     BlockInputStreamPtr loadIds(const std::vector<UInt64> & ids) override;
     BlockInputStreamPtr loadKeys(const Columns & key_columns, const std::vector<size_t> & requested_rows) override;
+    BlockInputStreamPtr loadBase(const String & query);
 
     bool isModified() const override;
     bool supportsSelectiveLoad() const override;