diff --git a/pglab/catalog/models/DatabasesTableModel.h b/pglab/catalog/models/DatabasesTableModel.h
index a8ecc8e..8e46aaa 100644
--- a/pglab/catalog/models/DatabasesTableModel.h
+++ b/pglab/catalog/models/DatabasesTableModel.h
@@ -38,9 +38,9 @@ public:
 	virtual Oid getType(int column) const override;
 	virtual QVariant getData(const QModelIndex &index) const override;
 
-    RowItem rowItem(int row) const
+    RowItem rowItem(const QModelIndex &index) const
     {
-        return databases.at(row).database;
+        return databases.at(index.row()).database;
     }
 protected:
     virtual QVariant getDataMeaning(const QModelIndex &index) const override;
diff --git a/pglab/catalog/models/TablesTableModel.cpp b/pglab/catalog/tables/TablesTableModel.cpp
similarity index 57%
rename from pglab/catalog/models/TablesTableModel.cpp
rename to pglab/catalog/tables/TablesTableModel.cpp
index fd285ed..8c80749 100644
--- a/pglab/catalog/models/TablesTableModel.cpp
+++ b/pglab/catalog/tables/TablesTableModel.cpp
@@ -5,15 +5,16 @@
 #include "catalog/PgClass.h"
 #include "catalog/PgClassContainer.h"
 #include "catalog/PgNamespace.h"
-#include "catalog/PgNamespaceContainer.h"
-#include "Pgsql_declare.h"
+#include "catalog/PgInheritsContainer.h"
+//#include "Pgsql_declare.h"
+#include "ui/catalog/tables/TableTreeBuilder.h"
 #include "CustomDataRole.h"
 #include <QBrush>
 #include <QtConcurrent>
 #include "Pgsql_Connection.h"
 
 TablesTableModel::TablesTableModel(std::shared_ptr<OpenDatabase> opendatabase, QObject *parent)
-	: QAbstractTableModel(parent)
+    : QAbstractItemModel(parent)
     , openDatabase(opendatabase)
 {}
 
@@ -36,17 +37,18 @@ void TablesTableModel::setCatalog(std::shared_ptr<const PgDatabaseCatalog> cat)
 bool TableLike(RelKind relkind)
 {
     switch (relkind) {
-        case RelKind::Table:
-        case RelKind::View:
-        case RelKind::MaterializedView:
-        case RelKind::ForeignTable:
-        case RelKind::PartitionedTable:
-            return true;
-        default:
-            return false;
+    case RelKind::Table:
+    case RelKind::View:
+    case RelKind::MaterializedView:
+    case RelKind::ForeignTable:
+    case RelKind::PartitionedTable:
+        return true;
+    default:
+        return false;
     }
 }
 
+
 void TablesTableModel::refresh()
 {
 	beginResetModel();
@@ -59,27 +61,17 @@ void TablesTableModel::refresh()
 	auto classes = m_catalog->classes();
 
     std::map<Oid, int> oidIndex;
-	m_tables.clear();
-	for (const auto &e : *classes) {
-		bool add = false;
-        if (TableLike(e.kind)) {
-			switch (m_namespaceFilter) {
-			case NamespaceFilter::User:
-				add = !e.ns().isSystemCatalog();
-				break;
-			case NamespaceFilter::PgCatalog:
-				add = e.ns().objectName() == "pg_catalog";
-				break;
-			case NamespaceFilter::InformationSchema:
-				add = e.ns().objectName() == "information_schema";
-				break;
-			}
-		}
-        if (add) {
-            m_tables.emplace_back(e);
-            oidIndex.emplace(e.oid(), m_tables.size() - 1);
-        }
-	}
+    rootNode.reset();
+
+    auto nsfilter = GetNamespaceFilterLambda();
+    std::map<Oid, PgClass> temp;
+    for (const auto &e : *classes)
+        if (TableLike(e.kind) && nsfilter(e))
+            temp.emplace(e.oid(), e);
+
+    TableTreeBuilder treeBuilder(temp, *m_catalog->inherits());
+    rootNode = treeBuilder.Build();
+
     StartLoadTableSizes(std::move(oidIndex));
 }
 
@@ -106,14 +98,46 @@ QVariant TablesTableModel::headerData(int section, Qt::Orientation orientation,
 	return QVariant();
 }
 
-int TablesTableModel::rowCount(const QModelIndex &) const
+int TablesTableModel::rowCount(const QModelIndex &parent) const
 {
-    return static_cast<int>(m_tables.size());
+    if (parent.isValid())
+    {
+        const TableNode *parentItem = static_cast<const TableNode*>(parent.internalPointer());
+        return static_cast<int>(parentItem->children.size());
+    }
+    if (rootNode != nullptr)
+        return static_cast<int>(rootNode->children.size());
+
+    return 0;
 }
 
 int TablesTableModel::columnCount(const QModelIndex &) const
 {
-	return colCount;
+    return colCount;
+}
+
+QModelIndex TablesTableModel::index(int row, int column, const QModelIndex &parent) const
+{
+    if (parent.isValid())
+    {
+        const TableNode *parentItem = static_cast<const TableNode*>(parent.internalPointer());
+        return createIndex(row, column, parentItem->getChildPtr(row));
+    }
+    return createIndex(row, column, rootNode->getChildPtr(row));
+}
+
+QModelIndex TablesTableModel::parent(const QModelIndex &index) const
+{
+    if (index.isValid())
+    {
+        const TableNode *item = static_cast<const TableNode*>(index.internalPointer());
+        auto parent = item->parent.lock();
+        if (parent && parent != rootNode)
+        {
+            return createIndex(parent->myIndex, 0, parent.get());
+        }
+    }
+    return {};
 }
 
 Oid TablesTableModel::getType(int column) const
@@ -142,36 +166,38 @@ Oid TablesTableModel::getType(int column) const
 
 QVariant TablesTableModel::getData(const QModelIndex &index) const
 {
-    const auto &table = m_tables[index.row()];
-    const auto &t = table._class;
-    const auto &s = table.sizes;
+//    const auto &table = rootNode->children[index.row()];
+    const TableNode* table = nodeFromIndex(index);
+    const auto &t = table->_class;
+    const auto &s = table->sizes;
+
 	switch (index.column()) {
-    case NameCol: return t.objectName();
-    case NamespaceCol: return t.nsName();
-    case KindCol: return t.typeName();
-    case OwnerCol: return t.ownerName();
-	case TablespaceCol: return getTablespaceDisplayString(*m_catalog, t.tablespace);
-    case OptionsCol: break;
-    case AclCol: return t.aclString();
-    case CommentCol: return t.description;
-    case TotalSizeCol: return s.oid == 0 ? QVariant() : s.totalBytes;
-    case TableSizeCol: return s.oid == 0 ? QVariant() : s.totalBytes - s.indexBytes - s.toastBytes;
-    case IndexSizeCol: return s.oid == 0 ? QVariant() : s.indexBytes;
-    case ToastSizeCol: return s.oid == 0 ? QVariant() : s.toastBytes;
+        case NameCol: return t.objectName();
+        case NamespaceCol: return t.nsName();
+        case KindCol: return t.typeName();
+        case OwnerCol: return t.ownerName();
+        case TablespaceCol: return getTablespaceDisplayString(*m_catalog, t.tablespace);
+        case OptionsCol: break;
+        case AclCol: return t.aclString();
+        case CommentCol: return t.description;
+        case TotalSizeCol: return s.oid == 0 ? QVariant() : s.totalBytes;
+        case TableSizeCol: return s.oid == 0 ? QVariant() : s.totalBytes - s.indexBytes - s.toastBytes;
+        case IndexSizeCol: return s.oid == 0 ? QVariant() : s.indexBytes;
+        case ToastSizeCol: return s.oid == 0 ? QVariant() : s.toastBytes;
     }
 
 	return QVariant();
 }
 
-PgClass TablesTableModel::getTable(int row) const
-{
-    return m_tables[row]._class;
-}
+//PgClass TablesTableModel::getTable(int row) const
+//{
+//    return rootNode->children[row]->_class;
+//}
 
-Oid TablesTableModel::getTableOid(int row) const
-{
-    return m_tables[row]._class.oid();
-}
+//Oid TablesTableModel::getTableOid(int row) const
+//{
+//    return rootNode->children[row]->_class.oid();
+//}
 
 QVariant TablesTableModel::data(const QModelIndex &index, int role) const
 {
@@ -256,16 +282,36 @@ TablesTableModel::TableSizes TablesTableModel::QueryTableSizes() const
 
 void TablesTableModel::PopulateSizes(std::map<Oid, int> oidIndex, std::vector<TableSize> sizes)
 {
-    for (auto s : sizes)
-    {
-        auto findIter = oidIndex.find(s.oid);
-        if (findIter != oidIndex.end())
-        {
-            m_tables[findIter->second].sizes = s;
-        }
-    }
-    emit dataChanged(
-        createIndex(0, TotalSizeCol),
-        createIndex(static_cast<int>(m_tables.size()), ToastSizeCol)
-        );
+//    for (auto s : sizes)
+//    {
+//        auto findIter = oidIndex.find(s.oid);
+//        if (findIter != oidIndex.end())
+//        {
+//            rootNode->children[findIter->second]->sizes = s;
+//        }
+//    }
+//    emit dataChanged(
+//        createIndex(0, TotalSizeCol),
+//        createIndex(static_cast<int>(rootNode->children.size()), ToastSizeCol)
+    //        );
+}
+
+const TableNode* TablesTableModel::nodeFromIndex(const QModelIndex &index)
+{
+    return static_cast<const TableNode*>(index.internalPointer());
+}
+
+std::function<bool (const PgClass &)> TablesTableModel::GetNamespaceFilterLambda()
+{
+    switch (m_namespaceFilter) {
+    case NamespaceFilter::User:
+        return [] (const PgClass &c) { return !c.ns().isSystemCatalog(); };
+
+    case NamespaceFilter::PgCatalog:
+        return [] (const PgClass &c) { return c.ns().objectName() == "pg_catalog"; };
+
+    case NamespaceFilter::InformationSchema:
+        return [] (const PgClass &c) { return c.ns().objectName() == "information_schema"; };
+    }
+
 }
diff --git a/pglab/catalog/models/TablesTableModel.h b/pglab/catalog/tables/TablesTableModel.h
similarity index 60%
rename from pglab/catalog/models/TablesTableModel.h
rename to pglab/catalog/tables/TablesTableModel.h
index 880dcd8..c204b60 100644
--- a/pglab/catalog/models/TablesTableModel.h
+++ b/pglab/catalog/tables/TablesTableModel.h
@@ -1,9 +1,12 @@
-#ifndef TABLESTABLEMODEL_H
+#ifndef TABLESTABLEMODEL_H
 #define TABLESTABLEMODEL_H
 
-#include "BaseTableModel.h"
+//#include "catalog/models/BaseTableModel.h"
+#include "ui/catalog/tables/TableNode.h"
+#include "ui/catalog/tables/TableSize.h"
 #include "NamespaceFilter.h"
 #include "catalog/PgClass.h"
+#include <QAbstractItemModel>
 #include <memory>
 #include <vector>
 
@@ -11,7 +14,7 @@ class OpenDatabase;
 class PgClass;
 class PgDatabaseCatalog;
 
-class TablesTableModel: public QAbstractTableModel {
+class TablesTableModel: public QAbstractItemModel {
 public:
     using RowItem = PgClass;
 	enum e_Columns : int {
@@ -40,42 +43,34 @@ public:
 	int rowCount(const QModelIndex &parent) const override;
 	int columnCount(const QModelIndex &parent) const override;
 
-	virtual QVariant data(const QModelIndex &index, int role) const override;
-	PgClass getTable(int row) const;
-    RowItem rowItem(int row) const
+    QModelIndex index(int row, int column,
+        const QModelIndex &parent = QModelIndex()) const override;
+
+    QModelIndex parent(const QModelIndex &index) const override;
+
+    QVariant data(const QModelIndex &index, int role) const override;
+
+//	PgClass getTable(int row) const;
+    RowItem rowItem(const QModelIndex &index) const
     {
-        return getTable(row);
+        return nodeFromIndex(index)->_class;
     }
-	Oid getTableOid(int row) const;
+//	Oid getTableOid(int row) const;
+
+    static const TableNode* nodeFromIndex(const QModelIndex &index);
 
 private:
-    class TableSize {
-    public:
-        int oid;
-        int64_t totalBytes = -1;
-        int64_t indexBytes = -1;
-        int64_t toastBytes = -1;
 
-        TableSize()
-            : oid(0)
-        {}
-    };
     using TableSizes = std::vector<TableSize>;
 
-    class Table {
-    public:
-        PgClass _class;
-        TableSize sizes;
-
-        Table(const PgClass &cls)
-            : _class(cls)
-        {}
-    };
-    using t_Tables = std::vector<Table>;
+    // this is a readonly model so when the vectors have been filled
+    // they will not change anymore and it is safe to assume the indexes
+    // of elements do not change
 
 	std::shared_ptr<const PgDatabaseCatalog> m_catalog;
 	NamespaceFilter m_namespaceFilter = NamespaceFilter::User;
-	t_Tables m_tables;
+    //t_Tables m_tables;
+    std::shared_ptr<TableNode> rootNode;
 	QMetaObject::Connection refreshConnection;
     std::shared_ptr<OpenDatabase> openDatabase;
 
@@ -87,6 +82,8 @@ private:
     TableSizes QueryTableSizes() const;
     void PopulateSizes(std::map<Oid, int> oidIndex, std::vector<TableSize> sizes);
 
+
+    std::function<bool(const PgClass&)> GetNamespaceFilterLambda();
 private slots:
 	void refresh();
 
diff --git a/pglab/catalog/widgets/CatalogTablesPage.cpp b/pglab/catalog/widgets/CatalogTablesPage.cpp
index 8782545..baeafff 100644
--- a/pglab/catalog/widgets/CatalogTablesPage.cpp
+++ b/pglab/catalog/widgets/CatalogTablesPage.cpp
@@ -8,7 +8,7 @@
 #include "catalog/widgets/TriggerPage.h"
 #include "catalog/models/ColumnTableModel.h"
 #include "catalog/models/ConstraintModel.h"
-#include "catalog/models/TablesTableModel.h"
+#include "catalog/tables/TablesTableModel.h"
 #include "util/PgLabTableView.h"
 #include "ResultTableModelUtil.h"
 #include "widgets/SqlCodePreview.h"
@@ -106,7 +106,7 @@ void CatalogTablesPage::setCatalog(std::shared_ptr<PgDatabaseCatalog> cat)
 void CatalogTablesPage::setNamespaceFilter(NamespaceFilter filter)
 {
     m_tablesTableView.dataModel()->setNamespaceFilter(filter);
-    m_tablesTableView.tableView()->resizeColumnsToContents();
+    //m_tablesTableView.tableView()->resizeColumnsToContents();
 }
 
 void CatalogTablesPage::tableListTable_currentRowChanged(const QModelIndex &current, const QModelIndex &previous)
@@ -114,8 +114,8 @@ void CatalogTablesPage::tableListTable_currentRowChanged(const QModelIndex &curr
     if (current.row() == previous.row())
         return;
 
-    auto table = m_tablesTableView.rowItemForProxyIndex(current);
-    selectedTableChanged(table);
+    auto tableNode = TablesTableModel::nodeFromIndex(m_tablesTableView.sortFilter()->mapToSource(current)); // m_tablesTableView.rowItemForProxyIndex(current);
+    selectedTableChanged(tableNode->_class);
 }
 
 
@@ -127,11 +127,15 @@ void CatalogTablesPage::tableListTable_layoutChanged(const QList<QPersistentMode
 
 void CatalogTablesPage::on_tableListTable_doubleClicked(const QModelIndex &index)
 {
-    auto row = m_tablesTableView.sortFilter()->mapToSource(index).row();
-    PgClass table = m_tablesTableView.dataModel()->getTable(row);
-	if (table.oid() != InvalidOid) {
-		tableSelected(table.oid());
-	}
+    auto sourceIndex = m_tablesTableView.sortFilter()->mapToSource(index);
+    auto tableNode = TablesTableModel::nodeFromIndex(sourceIndex);
+    if (tableNode)
+    {
+        Oid oid = tableNode->_class.oid();
+        if (oid != InvalidOid) {
+            tableSelected(oid);
+        }
+    }
 }
 
 void CatalogTablesPage::selectedTableChanged(const std::optional<PgClass> &table)
diff --git a/pglab/catalog/widgets/CatalogTablesPage.h b/pglab/catalog/widgets/CatalogTablesPage.h
index 02f61a5..01daf4b 100644
--- a/pglab/catalog/widgets/CatalogTablesPage.h
+++ b/pglab/catalog/widgets/CatalogTablesPage.h
@@ -2,13 +2,13 @@
 #define CATALOGTABLESPAGE_H
 
 #include "NamespaceFilter.h"
-#include "catalog/models/TablesTableModel.h"
+#include "catalog/tables/TablesTableModel.h"
 #include "util/PgLabTableViewHelper.h"
 #include <QSplitter>
 #include <memory>
 #include <optional>
 #include <QAbstractItemModel>
-#include "Pgsql_oids.h"
+
 
 class CatalogConstraintPage;
 class CatalogIndexPage;
@@ -39,7 +39,7 @@ public:
 signals:
 	void tableSelected(Oid tableoid);
 private:
-    PgLabTableViewHelper<TablesTableModel> m_tablesTableView;
+    PgLabTableViewHelper<TablesTableModel, QTreeView> m_tablesTableView;
 
 	// Details
 	QTabWidget *m_detailsTabs = nullptr;
diff --git a/pglab/pglab.pro b/pglab/pglab.pro
index 2c24c63..2ff93a5 100644
--- a/pglab/pglab.pro
+++ b/pglab/pglab.pro
@@ -32,8 +32,8 @@ SOURCES += main.cpp\
     catalog/models/ProcTableModel.cpp \
     catalog/models/RolesTableModel.cpp \
     catalog/models/SequenceModel.cpp \
-    catalog/models/TablesTableModel.cpp \
     catalog/models/TriggerTableModel.cpp \
+    catalog/tables/TablesTableModel.cpp \
     catalog/widgets/CatalogConstraintPage.cpp \
     catalog/widgets/CatalogFunctionsPage.cpp \
     catalog/widgets/CatalogIndexPage.cpp \
@@ -104,8 +104,8 @@ HEADERS  += \
     catalog/models/ProcTableModel.h \
     catalog/models/RolesTableModel.h \
     catalog/models/SequenceModel.h \
-    catalog/models/TablesTableModel.h \
     catalog/models/TriggerTableModel.h \
+    catalog/tables/TablesTableModel.h \
     catalog/widgets/CatalogConstraintPage.h \
     catalog/widgets/CatalogFunctionsPage.h \
     catalog/widgets/CatalogIndexPage.h \
diff --git a/pglab/util/PgLabTableViewHelper.h b/pglab/util/PgLabTableViewHelper.h
index 67b5e55..e2c88c8 100644
--- a/pglab/util/PgLabTableViewHelper.h
+++ b/pglab/util/PgLabTableViewHelper.h
@@ -1,19 +1,34 @@
 #pragma once
 
 #include <QTableWidget>
+#include <QTreeView>
 #include <QSortFilterProxyModel>
 #include "util/PgLabTableView.h"
 #include <optional>
 
 class PgDatabaseCatalog;
 
-template <typename TableModel>
+template <typename ViewType>
+void ResizeColumnsToContent(ViewType *vt)
+{
+    vt->resizeColumnsToContents();
+}
+
+template <>
+inline void ResizeColumnsToContent<QTreeView>(QTreeView *)
+{
+}
+
+
+
+
+template <typename TableModel, typename ViewType = PgLabTableView>
 class PgLabTableViewHelper {
 public:
 
     PgLabTableViewHelper(QWidget * parent, TableModel *tableModel)
     {
-        m_tableView = new PgLabTableView(parent);
+        m_tableView = new ViewType(parent);
 
         m_dataModel = tableModel;
         m_sortFilter = new QSortFilterProxyModel(parent);
@@ -27,7 +42,7 @@ public:
         : PgLabTableViewHelper(parent, new TableModel(parent))
     {}
 
-    PgLabTableView *tableView() const
+    ViewType *tableView() const
     {
         return m_tableView;
     }
@@ -45,7 +60,7 @@ public:
     void setCatalog(std::shared_ptr<PgDatabaseCatalog> cat)
     {
         m_dataModel->setCatalog(cat);
-        m_tableView->resizeColumnsToContents();
+        ResizeColumnsToContent(m_tableView);
     }
 
     QModelIndex currentSourceIndex() const
@@ -57,15 +72,15 @@ public:
         return m_sortFilter->mapToSource(index);
     }
 
-    typename TableModel::RowItem rowItemForSourceRow(int row) const
+    typename TableModel::RowItem rowItemForSourceRow(QModelIndex index) const
     {
-        return m_dataModel->rowItem(row);
+        return m_dataModel->rowItem(index);
     }
 
     typename TableModel::RowItem rowItemForProxyIndex(QModelIndex index)
     {
         QModelIndex sourceIndex = m_sortFilter->mapToSource(index);
-        return m_dataModel->rowItem(sourceIndex.row());
+        return m_dataModel->rowItem(sourceIndex);
     }
 
     typename TableModel::RowItem rowItemForProxyRow(int row) const
@@ -79,12 +94,12 @@ public:
         if (!index.isValid())
             return {};
 
-        return rowItemForSourceRow(index.row());
+        return rowItemForSourceRow(index);
     }
 
 
 private:
-    PgLabTableView *m_tableView = nullptr;
+    ViewType *m_tableView = nullptr;
     TableModel *m_dataModel = nullptr;
     QSortFilterProxyModel *m_sortFilter = nullptr;
 };
diff --git a/pglablib/catalog/PgInheritsContainer.h b/pglablib/catalog/PgInheritsContainer.h
index 3d95377..b94640c 100644
--- a/pglablib/catalog/PgInheritsContainer.h
+++ b/pglablib/catalog/PgInheritsContainer.h
@@ -4,17 +4,24 @@
 
 #include "PgContainer.h"
 #include "PgInherits.h"
-#include "Pgsql_declare.h"
 
+class IFindParents
+{
+public:
+    virtual std::vector<Oid> getParentsOf(Oid oid) const = 0;
+};
 
-class PgInheritsContainer : public PgContainer<PgInherits, PgInherits::Key> {
+class PgInheritsContainer
+    : public PgContainer<PgInherits, PgInherits::Key>
+    , public IFindParents
+{
 public:
 	using PgContainer<PgInherits, PgInherits::Key>::PgContainer;
 
 	virtual std::string getLoadQuery() const override;
 
 	/// Returns the parents in the correct order
-	std::vector<Oid> getParentsOf(Oid oid) const;
+    std::vector<Oid> getParentsOf(Oid oid) const override;
 protected:
 	PgInherits loadElem(const Pgsql::Row &row) override;
 };
diff --git a/pglablib/pglablib.pro b/pglablib/pglablib.pro
index a835755..876bd84 100644
--- a/pglablib/pglablib.pro
+++ b/pglablib/pglablib.pro
@@ -45,6 +45,9 @@ SOURCES += \
     catalog/PgConstraintContainer.cpp \
     ParamListJson.cpp \
     ParamListModel.cpp \
+    ui/catalog/tables/TableNode.cpp \
+    ui/catalog/tables/TableSize.cpp \
+    ui/catalog/tables/TableTreeBuilder.cpp \
     util.cpp \
     SqlFormattingUtils.cpp \
     catalog/PgKeywordList.cpp \
@@ -113,6 +116,9 @@ HEADERS += \
     catalog/PgConstraintContainer.h \
     ParamListJson.h \
     ParamListModel.h \
+    ui/catalog/tables/TableNode.h \
+    ui/catalog/tables/TableSize.h \
+    ui/catalog/tables/TableTreeBuilder.h \
     util.h \ 
     SqlFormattingUtils.h \
     catalog/PgCatalogTypes.h \
diff --git a/pglablib/ui/catalog/tables/TableNode.cpp b/pglablib/ui/catalog/tables/TableNode.cpp
new file mode 100644
index 0000000..ec89c07
--- /dev/null
+++ b/pglablib/ui/catalog/tables/TableNode.cpp
@@ -0,0 +1,20 @@
+#include "TableNode.h"
+#include "catalog/PgDatabaseCatalog.h"
+namespace {
+    PgDatabaseCatalog dummyCatalog;
+}
+
+TableNode::TableNode()
+: _class(dummyCatalog, InvalidOid, "", InvalidOid)
+{
+
+}
+
+TableNode::TableNode(const PgClass &cls)
+: _class(cls)
+{}
+
+const TableNode *TableNode::getChildPtr(int index) const
+{
+    return children.at(index).get();
+}
diff --git a/pglablib/ui/catalog/tables/TableNode.h b/pglablib/ui/catalog/tables/TableNode.h
new file mode 100644
index 0000000..6e462b6
--- /dev/null
+++ b/pglablib/ui/catalog/tables/TableNode.h
@@ -0,0 +1,25 @@
+#pragma once
+
+#include "TableSize.h"
+#include "catalog/PgClass.h"
+
+class TableNode;
+using t_Tables = std::vector<std::shared_ptr<TableNode>>;
+
+
+
+
+class TableNode {
+public:
+    PgClass _class;
+    TableSize sizes;
+
+    int myIndex;
+    std::weak_ptr<TableNode> parent; // hope we do not need it (must be weak to prevent circular reference)
+    t_Tables children;
+
+    TableNode();
+    TableNode(const PgClass &cls);
+
+    const TableNode* getChildPtr(int index) const;
+};
diff --git a/pglablib/ui/catalog/tables/TableSize.cpp b/pglablib/ui/catalog/tables/TableSize.cpp
new file mode 100644
index 0000000..e411142
--- /dev/null
+++ b/pglablib/ui/catalog/tables/TableSize.cpp
@@ -0,0 +1,6 @@
+#include "TableSize.h"
+
+
+TableSize::TableSize()
+: oid(0)
+{}
diff --git a/pglablib/ui/catalog/tables/TableSize.h b/pglablib/ui/catalog/tables/TableSize.h
new file mode 100644
index 0000000..56da2c5
--- /dev/null
+++ b/pglablib/ui/catalog/tables/TableSize.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#include <cstdint>
+
+class TableSize {
+public:
+    int oid;
+    int64_t totalBytes = -1;
+    int64_t indexBytes = -1;
+    int64_t toastBytes = -1;
+
+    TableSize();
+};
diff --git a/pglablib/ui/catalog/tables/TableTreeBuilder.cpp b/pglablib/ui/catalog/tables/TableTreeBuilder.cpp
new file mode 100644
index 0000000..430210f
--- /dev/null
+++ b/pglablib/ui/catalog/tables/TableTreeBuilder.cpp
@@ -0,0 +1,89 @@
+#include "TableTreeBuilder.h"
+#include "catalog/PgInheritsContainer.h"
+#include "TableNode.h"
+#include <ranges>
+
+TableTreeBuilder::TableTreeBuilder(
+    const std::map<Oid, PgClass> &source,
+    const IFindParents &inheritance
+)
+: source(source)
+, inheritance(inheritance)
+{
+}
+
+std::shared_ptr<TableNode> TableTreeBuilder::Build()
+{
+    rootNode = std::make_shared<TableNode>();
+
+    // when childrens are ordered before there parents
+    // the parent will automatically be added first (recursively)
+    // processed nodes are tracked in the nodes member
+    for (auto && e : source | std::views::filter(
+        [this] (auto &e)
+        {
+            return processedNodes.count(e.first) == 0;
+        })
+    )
+    {
+        addNode(e.second);
+    }
+    AssignNodeIndexesAndParents(rootNode);
+    auto ret = rootNode;
+    resetState();
+    return ret;
+}
+
+void TableTreeBuilder::resetState()
+{
+    rootNode.reset();
+    processedNodes.clear();
+}
+
+std::shared_ptr<TableNode>  TableTreeBuilder::addNode(const PgClass &cls)
+{
+    std::shared_ptr<TableNode> node = std::make_shared<TableNode>(cls);
+    processedNodes.emplace(cls.oid(), node);
+    std::vector<Oid> parents = inheritance.getParentsOf(cls.oid());
+    if (parents.empty())
+        addToplevelNode(node);
+    else
+        addToParents(node, parents);
+    return node;
+}
+
+void TableTreeBuilder::addToplevelNode(std::shared_ptr<TableNode> node)
+{
+    rootNode->children.push_back(node);
+}
+
+void TableTreeBuilder::addToParents(std::shared_ptr<TableNode> node, const std::vector<Oid> &parents)
+{
+    for (auto &parent : parents)
+    {
+        getParent(parent)->children.push_back(node);
+    }
+}
+
+std::shared_ptr<TableNode> TableTreeBuilder::getParent(Oid oid)
+{
+    auto parent = processedNodes.find(oid);
+    if (parent != processedNodes.end())
+        return parent->second;
+
+    // Not present, find in source list and add now
+    auto source_iter = source.find(oid);
+    assert(source_iter != source.end());
+    return addNode(source_iter->second);
+}
+
+void TableTreeBuilder::AssignNodeIndexesAndParents(std::shared_ptr<TableNode> parent)
+{
+    int index = 0;
+    for (auto &n : parent->children)
+    {
+        n->parent = parent;
+        n->myIndex = index++;
+        AssignNodeIndexesAndParents(n);
+    }
+}
diff --git a/pglablib/ui/catalog/tables/TableTreeBuilder.h b/pglablib/ui/catalog/tables/TableTreeBuilder.h
new file mode 100644
index 0000000..0a4949f
--- /dev/null
+++ b/pglablib/ui/catalog/tables/TableTreeBuilder.h
@@ -0,0 +1,32 @@
+#pragma once
+
+#include "Pgsql_oids.h"
+#include <map>
+#include <memory>
+
+class PgClass;
+class TableNode;
+class IFindParents;
+
+class TableTreeBuilder
+{
+public:
+    TableTreeBuilder(const std::map<Oid, PgClass> &source, const IFindParents &inheritance);
+
+    std::shared_ptr<TableNode> Build();
+
+private:
+    const std::map<Oid, PgClass> &source;
+    const IFindParents &inheritance;
+    std::map<Oid, std::shared_ptr<TableNode>> processedNodes;
+    std::shared_ptr<TableNode> rootNode;
+
+    void resetState();
+    bool hasParent(const PgClass &cls) const;
+    std::shared_ptr<TableNode>  addNode(const PgClass &cls);
+    void addToplevelNode(std::shared_ptr<TableNode> node);
+    void addToParents(std::shared_ptr<TableNode> node, const std::vector<Oid> &parents);
+    std::shared_ptr<TableNode> getParent(Oid oid);
+    void AssignNodeIndexesAndParents(std::shared_ptr<TableNode> parent);
+};
+
diff --git a/tests/pglabtests/TableTreeBuilderTests.cpp b/tests/pglabtests/TableTreeBuilderTests.cpp
new file mode 100644
index 0000000..68beb2e
--- /dev/null
+++ b/tests/pglabtests/TableTreeBuilderTests.cpp
@@ -0,0 +1,64 @@
+#include <gtest/gtest.h>
+#include "PrintTo_Qt.h"
+
+#include "catalog/PgClass.h"
+#include "catalog/PgDatabaseCatalog.h"
+#include "ui/catalog/tables/TableTreeBuilder.h"
+#include "ui/catalog/tables/TableNode.h"
+#include "catalog/PgInheritsContainer.h"
+
+TEST(TableTreeBuilder, EmptySourceEmptyResult)
+{
+    std::map<Oid, PgClass> source;
+    PgDatabaseCatalog catalog;
+    PgInheritsContainer inherited(catalog);
+    TableTreeBuilder builder(source, inherited);
+    auto result = builder.Build();
+
+    EXPECT_EQ(result->children.size(), 0);
+}
+
+
+TEST(TableTreeBuilder, TopLevelOnly)
+{
+    std::map<Oid, PgClass> source;
+
+    PgDatabaseCatalog catalog;
+    PgClass cls1(catalog, 1000, "a", 11);
+    source.emplace(1000, cls1);
+    PgInheritsContainer inherited(catalog);
+    TableTreeBuilder builder(source, inherited);
+    auto result = builder.Build();
+
+    EXPECT_EQ(result->children.size(), 1);
+}
+
+class FakeIFindParents : public IFindParents
+{
+public:
+    std::vector<Oid> getParentsOf(Oid oid) const override
+    {
+        if (oid == 1001)
+            return { 1002 };
+        return {};
+    }
+};
+
+TEST(TableTreeBuilder, WithChild)
+{
+    std::map<Oid, PgClass> source;
+
+    FakeIFindParents findParents;
+    PgDatabaseCatalog catalog;
+    PgClass cls1(catalog, 1001, "a", 11);
+    source.emplace(1001, cls1);
+    PgClass cls2(catalog, 1002, "b", 11);
+    source.emplace(1002, cls2);
+    PgInheritsContainer inherited(catalog);
+    TableTreeBuilder builder(source, findParents);
+    auto result = builder.Build();
+
+    EXPECT_EQ(result->children.size(), 1);
+    EXPECT_EQ(result->children[0]->children.size(), 1);
+    EXPECT_TRUE(result->children[0]->children[0]->parent.lock() == result->children[0]);
+}
diff --git a/tests/pglabtests/pglabtests.pro b/tests/pglabtests/pglabtests.pro
index 3e8fb6c..a5405b1 100644
--- a/tests/pglabtests/pglabtests.pro
+++ b/tests/pglabtests/pglabtests.pro
@@ -14,6 +14,7 @@ QT       += core widgets
 HEADERS +=     
 
 SOURCES +=     main.cpp \
+    TableTreeBuilderTests.cpp \
     tst_ConvertLangToSqlString.cpp \
     tst_ConvertToMultiLineCString.cpp \
     tst_ExplainJsonParser.cpp \