@@ -29,6 +29,7 @@
 using Npgsql.TypeHandlers;
 using Npgsql.TypeHandlers.DateTimeHandlers;
 using Npgsql.TypeHandlers.NumericHandlers;
+using NpgsqlTypes;
 
 namespace Npgsql
 {
@@ -46,29 +47,29 @@ class PostgresMinimalDatabaseInfo : PostgresDatabaseInfo
     {
         static readonly PostgresType[] Types = new[]
         {
-            new PostgresBaseType("pg_catalog", "int4",        Int32Handler.TypeOID),
-            new PostgresBaseType("pg_catalog", "int2",        Int16Handler.TypeOID),
-            new PostgresBaseType("pg_catalog", "int8",        Int64Handler.TypeOID),
-            new PostgresBaseType("pg_catalog", "float4",      SingleHandler.TypeOID),
-            new PostgresBaseType("pg_catalog", "float8",      DoubleHandler.TypeOID),
-            new PostgresBaseType("pg_catalog", "numeric",     NumericHandler.TypeOID),
-            new PostgresBaseType("pg_catalog", "money",       MoneyHandler.TypeOID),
+            new PostgresBaseType("pg_catalog", "int4",        (uint)NpgsqlDbType.Integer),
+            new PostgresBaseType("pg_catalog", "int2",        (uint)NpgsqlDbType.Smallint),
+            new PostgresBaseType("pg_catalog", "int8",        (uint)NpgsqlDbType.Bigint),
+            new PostgresBaseType("pg_catalog", "float4",      (uint)NpgsqlDbType.Real),
+            new PostgresBaseType("pg_catalog", "float8",      (uint)NpgsqlDbType.Double),
+            new PostgresBaseType("pg_catalog", "numeric",     (uint)NpgsqlDbType.Numeric),
+            new PostgresBaseType("pg_catalog", "money",       (uint)NpgsqlDbType.Money),
 
-            new PostgresBaseType("pg_catalog", "text",        TextHandler.TextTypeOID),
-            new PostgresBaseType("pg_catalog", "varchar",     TextHandler.VarcharTypeOID),
-            new PostgresBaseType("pg_catalog", "char",        TextHandler.CharTypeOID),
-            new PostgresBaseType("pg_catalog", "unknown",     TextHandler.UnknownTypeOID),
+            new PostgresBaseType("pg_catalog", "text",        (uint)NpgsqlDbType.Text),
+            new PostgresBaseType("pg_catalog", "varchar",     (uint)NpgsqlDbType.Varchar),
+            new PostgresBaseType("pg_catalog", "char",        (uint)NpgsqlDbType.Char),
+            new PostgresBaseType("pg_catalog", "unknown",     (uint)NpgsqlDbType.Unknown),
 
-            new PostgresBaseType("pg_catalog", "timestamp",   TimestampHandler.TypeOID),
-            new PostgresBaseType("pg_catalog", "timestamptz", TimestampTzHandler.TypeOID),
-            new PostgresBaseType("pg_catalog", "date",        DateHandler.TypeOID),
-            new PostgresBaseType("pg_catalog", "time",        TimeHandler.TypeOID),
-            new PostgresBaseType("pg_catalog", "timetz",      TimeTzHandler.TypeOID),
-            new PostgresBaseType("pg_catalog", "interval",    IntervalHandler.TypeOID),
+            new PostgresBaseType("pg_catalog", "timestamp",   (uint)NpgsqlDbType.Timestamp),
+            new PostgresBaseType("pg_catalog", "timestamptz", (uint)NpgsqlDbType.TimestampTz),
+            new PostgresBaseType("pg_catalog", "date",        (uint)NpgsqlDbType.Date),
+            new PostgresBaseType("pg_catalog", "time",        (uint)NpgsqlDbType.Time),
+            new PostgresBaseType("pg_catalog", "timetz",      (uint)NpgsqlDbType.TimeTz),
+            new PostgresBaseType("pg_catalog", "interval",    (uint)NpgsqlDbType.Interval),
 
-            new PostgresBaseType("pg_catalog", "bool",        BoolHandler.TypeOID),
-            new PostgresBaseType("pg_catalog", "bytea",       ByteaHandler.TypeOID),
-            new PostgresBaseType("pg_catalog", "uuid",        UuidHandler.TypeOID)
+            new PostgresBaseType("pg_catalog", "bool",        (uint)NpgsqlDbType.Boolean),
+            new PostgresBaseType("pg_catalog", "bytea",       (uint)NpgsqlDbType.Bytea),
+            new PostgresBaseType("pg_catalog", "uuid",        (uint)NpgsqlDbType.Uuid)
         };
 
         protected override IEnumerable<PostgresType> GetTypes() => Types;
 
@@ -37,8 +37,6 @@ namespace Npgsql.TypeHandlers
     [TypeMapping("bool", NpgsqlDbType.Boolean, DbType.Boolean, typeof(bool))]
     class BoolHandler : NpgsqlSimpleTypeHandler<bool>
     {
-        internal const uint TypeOID = 16;
-
         public override bool Read(NpgsqlReadBuffer buf, int len, FieldDescription fieldDescription = null)
             => buf.ReadByte() != 0;
 
 
@@ -38,8 +38,6 @@ namespace Npgsql.TypeHandlers
     [TypeMapping("bytea", NpgsqlDbType.Bytea, DbType.Binary, new[] { typeof(byte[]), typeof(ArraySegment<byte>) })]
     public class ByteaHandler : NpgsqlTypeHandler<byte[]>, INpgsqlTypeHandler<ArraySegment<byte>>
     {
-        internal const uint TypeOID = 17;
-
         /// <inheritdoc />
         public override async ValueTask<byte[]> Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription fieldDescription = null)
         {
 
@@ -43,8 +43,6 @@ protected override NpgsqlTypeHandler<DateTime> Create(NpgsqlConnection conn)
     /// </remarks>
     class DateHandler : NpgsqlSimpleTypeHandlerWithPsv<DateTime, NpgsqlDate>
     {
-        internal const uint TypeOID = 1082;
-
         internal const int PostgresEpochJdate = 2451545; // == date2j(2000, 1, 1)
         internal const int MonthsPerYear = 12;
 
 
@@ -43,8 +43,6 @@ protected override NpgsqlTypeHandler<TimeSpan> Create(NpgsqlConnection conn)
     /// </remarks>
     class IntervalHandler : NpgsqlSimpleTypeHandlerWithPsv<TimeSpan, NpgsqlTimeSpan>
     {
-        internal const uint TypeOID = 1186;
-
         /// <summary>
         /// A deprecated compile-time option of PostgreSQL switches to a floating-point representation of some date/time
         /// fields. Some PostgreSQL-like databases (e.g. CrateDB) use floating-point representation by default and do not
 
@@ -44,8 +44,6 @@ protected override NpgsqlTypeHandler<TimeSpan> Create(NpgsqlConnection conn)
     /// </remarks>
     class TimeHandler : NpgsqlSimpleTypeHandler<TimeSpan>
     {
-        internal const uint TypeOID = 1083;
-
         /// <summary>
         /// A deprecated compile-time option of PostgreSQL switches to a floating-point representation of some date/time
         /// fields. Some PostgreSQL-like databases (e.g. CrateDB) use floating-point representation by default and do not
 
@@ -44,8 +44,6 @@ protected override NpgsqlTypeHandler<DateTimeOffset> Create(NpgsqlConnection con
     /// </remarks>
     class TimeTzHandler : NpgsqlSimpleTypeHandler<DateTimeOffset>, INpgsqlSimpleTypeHandler<DateTime>, INpgsqlSimpleTypeHandler<TimeSpan>
     {
-        internal const uint TypeOID = 1266;
-
         /// <summary>
         /// A deprecated compile-time option of PostgreSQL switches to a floating-point representation of some date/time
         /// fields. Some PostgreSQL-like databases (e.g. CrateDB) use floating-point representation by default and do not
 
@@ -44,8 +44,6 @@ protected override NpgsqlTypeHandler<DateTime> Create(NpgsqlConnection conn)
     /// </remarks>
     class TimestampTzHandler : TimestampHandler
     {
-        internal new const uint TypeOID = 1184;
-
         public TimestampTzHandler(bool integerFormat, bool convertInfinityDateTime)
             : base(integerFormat, convertInfinityDateTime) {}
 
 
@@ -37,8 +37,6 @@ namespace Npgsql.TypeHandlers.NumericHandlers
     [TypeMapping("float8", NpgsqlDbType.Double, DbType.Double, typeof(double))]
     class DoubleHandler : NpgsqlSimpleTypeHandler<double>
     {
-        internal const uint TypeOID = 701;
-
         public override double Read(NpgsqlReadBuffer buf, int len, FieldDescription fieldDescription = null)
             => buf.ReadDouble();
Original file line number	Diff line number	Diff line change
`@@ -37,8 +37,6 @@ namespace Npgsql.TypeHandlers`
`37`	`37`	`[TypeMapping("bool", NpgsqlDbType.Boolean, DbType.Boolean, typeof(bool))]`
`38`	`38`	`class BoolHandler : NpgsqlSimpleTypeHandler<bool>`
`39`	`39`	`{`
`40`		`- internal const uint TypeOID = 16;`
`41`		`-`
`42`	`40`	`public override bool Read(NpgsqlReadBuffer buf, int len, FieldDescription fieldDescription = null)`
`43`	`41`	`=> buf.ReadByte() != 0;`
`44`	`42`
Original file line number	Diff line number	Diff line change
`@@ -38,8 +38,6 @@ namespace Npgsql.TypeHandlers`
`38`	`38`	`[TypeMapping("bytea", NpgsqlDbType.Bytea, DbType.Binary, new[] { typeof(byte[]), typeof(ArraySegment<byte>) })]`
`39`	`39`	`public class ByteaHandler : NpgsqlTypeHandler<byte[]>, INpgsqlTypeHandler<ArraySegment<byte>>`
`40`	`40`	`{`
`41`		`- internal const uint TypeOID = 17;`
`42`		`-`
`43`	`41`	`/// <inheritdoc />`
`44`	`42`	`public override async ValueTask<byte[]> Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription fieldDescription = null)`
`45`	`43`	`{`
Original file line number	Diff line number	Diff line change
`@@ -43,8 +43,6 @@ protected override NpgsqlTypeHandler<DateTime> Create(NpgsqlConnection conn)`
`43`	`43`	`/// </remarks>`
`44`	`44`	`class DateHandler : NpgsqlSimpleTypeHandlerWithPsv<DateTime, NpgsqlDate>`
`45`	`45`	`{`
`46`		`- internal const uint TypeOID = 1082;`
`47`		`-`
`48`	`46`	`internal const int PostgresEpochJdate = 2451545; // == date2j(2000, 1, 1)`
`49`	`47`	`internal const int MonthsPerYear = 12;`
`50`	`48`
Original file line number	Diff line number	Diff line change
`@@ -44,8 +44,6 @@ protected override NpgsqlTypeHandler<TimeSpan> Create(NpgsqlConnection conn)`
`44`	`44`	`/// </remarks>`
`45`	`45`	`class TimeHandler : NpgsqlSimpleTypeHandler<TimeSpan>`
`46`	`46`	`{`
`47`		`- internal const uint TypeOID = 1083;`
`48`		`-`
`49`	`47`	`/// <summary>`
`50`	`48`	`/// A deprecated compile-time option of PostgreSQL switches to a floating-point representation of some date/time`
`51`	`49`	`/// fields. Some PostgreSQL-like databases (e.g. CrateDB) use floating-point representation by default and do not`