diff --git a/internal/db/postgres/context/table.go b/internal/db/postgres/context/table.go
index 5867efd0..e7e55f57 100644
--- a/internal/db/postgres/context/table.go
+++ b/internal/db/postgres/context/table.go
@@ -30,6 +30,30 @@ import (
 	"github.com/greenmaskio/greenmask/pkg/toolkit"
 )
 
+var typeSizes = map[string]int{
+	"int2":   2,
+	"int4":   4,
+	"int8":   8,
+	"float4": 4,
+	"float8": 8,
+}
+
+func getTypeSizeByeName(name string) int {
+	res, ok := typeSizes[name]
+	if !ok {
+		return -1
+	}
+	return res
+}
+
+func getTypeOidByName(name string, typeMap *pgtype.Map) toolkit.Oid {
+	t, ok := typeMap.TypeForName(name)
+	if !ok {
+		return toolkit.Oid(t.OID)
+	}
+	return 0
+}
+
 // ValidateAndBuildTableConfig - validates tables, toolkit and their parameters. Builds config for tables and returns
 // ValidationWarnings that can be used for checking helpers in configuring and debugging transformation. Those
 // may contain the schema affection warnings that would be useful for considering consistency
@@ -58,23 +82,25 @@ func validateAndBuildTablesConfig(
 			}
 			table.Constraints = constraints
 
+			// Assign columns and transformersMap if were found
+			columns, err := getColumnsConfig(ctx, tx, table.Oid, version)
+			if err != nil {
+				return nil, nil, err
+			}
+			table.Columns = columns
+
 			// Assigning overridden column types for driver initialization
 			if tableCfg.ColumnsTypeOverride != nil {
 				for _, c := range table.Columns {
 					overridingType, ok := tableCfg.ColumnsTypeOverride[c.Name]
 					if ok {
 						c.OverriddenTypeName = overridingType
+						c.OverriddenTypeSize = getTypeSizeByeName(overridingType)
+						c.OverriddenTypeOid = getTypeOidByName(overridingType, typeMap)
 					}
 				}
 			}
 
-			// Assign columns and transformersMap if were found
-			columns, err := getColumnsConfig(ctx, tx, table.Oid, version)
-			if err != nil {
-				return nil, nil, err
-			}
-			table.Columns = columns
-
 			driver, driverWarnings, err := toolkit.NewDriver(table.Table, types)
 			if err != nil {
 				return nil, nil, fmt.Errorf("unnable to initialise driver: %w", err)
diff --git a/pkg/toolkit/column.go b/pkg/toolkit/column.go
index 5030464f..51cae52b 100644
--- a/pkg/toolkit/column.go
+++ b/pkg/toolkit/column.go
@@ -29,11 +29,21 @@ type Column struct {
 	// OverriddenTypeName - replacement of  original type. For instance override TEXT to INT2
 	OverriddenTypeName string `json:"overridden_type_name"`
 	OverriddenTypeOid  Oid    `json:"overridden_type_oid"`
+	OverriddenTypeSize int    `json:"overridden_type_size"`
 }
 
 func (c *Column) GetColumnSize() int {
-	if c.Length != -1 {
+	if c.OverriddenTypeSize != 0 {
+		return c.OverriddenTypeSize
+	} else if c.Length != -1 {
 		return c.Length
 	}
 	return c.TypeLength
 }
+
+func (c *Column) GetType() (string, Oid) {
+	if c.OverriddenTypeName != "" {
+		return c.OverriddenTypeName, c.OverriddenTypeOid
+	}
+	return c.TypeName, c.TypeOid
+}
diff --git a/pkg/toolkit/static_parameter.go b/pkg/toolkit/static_parameter.go
index e1357fce..710aebc9 100644
--- a/pkg/toolkit/static_parameter.go
+++ b/pkg/toolkit/static_parameter.go
@@ -144,12 +144,7 @@ func (sp *StaticParameter) Init(columnParams map[string]*StaticParameter, rawVal
 		}
 		sp.Column = column
 
-		columnTypeName := sp.Column.TypeName
-		columnTypeOid := sp.Column.TypeOid
-		if sp.Column.OverriddenTypeName != "" {
-			columnTypeName = sp.Column.OverriddenTypeName
-			columnTypeOid = 0
-		}
+		columnTypeName, columnTypeOid := sp.Column.GetType()
 
 		if sp.definition.ColumnProperties != nil &&
 			len(sp.definition.ColumnProperties.AllowedTypes) > 0 &&