Faster/easier loading of types

conn.go

@@ -107,8 +107,10 @@ var (
 	ErrTooManyRows = errors.New("too many rows in result set")
 )
 
-var errDisabledStatementCache = fmt.Errorf("cannot use QueryExecModeCacheStatement with disabled statement cache")
-var errDisabledDescriptionCache = fmt.Errorf("cannot use QueryExecModeCacheDescribe with disabled description cache")
+var (
+	errDisabledStatementCache   = fmt.Errorf("cannot use QueryExecModeCacheStatement with disabled statement cache")
+	errDisabledDescriptionCache = fmt.Errorf("cannot use QueryExecModeCacheDescribe with disabled description cache")
+)
 
 // Connect establishes a connection with a PostgreSQL server with a connection string. See
 // pgconn.Connect for details.
@@ -843,7 +845,6 @@ func (c *Conn) getStatementDescription(
 	mode QueryExecMode,
 	sql string,
 ) (sd *pgconn.StatementDescription, err error) {
-
 	switch mode {
 	case QueryExecModeCacheStatement:
 		if c.statementCache == nil {

derived_types.go

@@ -0,0 +1,260 @@
+package pgx
+
+import (
+	"context"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+/*
+buildLoadDerivedTypesSQL generates the correct query for retrieving type information.
+
+	pgVersion: the major version of the PostgreSQL server
+	typeNames: the names of the types to load. If nil, load all types.
+*/
+func buildLoadDerivedTypesSQL(pgVersion int64, typeNames []string) string {
+	supportsMultirange := (pgVersion >= 14)
+	var typeNamesClause string
+
+	if typeNames == nil {
+		// This should not occur; this will not return any types
+		typeNamesClause = "= ''"
+	} else {
+		typeNamesClause = "= ANY($1)"
+	}
+	parts := make([]string, 0, 10)
+
+	// Each of the type names provided might be found in pg_class or pg_type.
+	// Additionally, it may or may not include a schema portion.
+	parts = append(parts, `
+WITH RECURSIVE
+-- find the OIDs in pg_class which match one of the provided type names
+selected_classes(oid,reltype) AS (
+    -- this query uses the namespace search path, so will match type names without a schema prefix
+    SELECT pg_class.oid, pg_class.reltype
+    FROM pg_catalog.pg_class
+        LEFT JOIN pg_catalog.pg_namespace n ON n.oid = pg_class.relnamespace
+    WHERE pg_catalog.pg_table_is_visible(pg_class.oid)
+      AND relname `, typeNamesClause, `
+UNION ALL
+    -- this query will only match type names which include the schema prefix
+    SELECT pg_class.oid, pg_class.reltype
+    FROM pg_class
+    INNER JOIN pg_namespace ON (pg_class.relnamespace = pg_namespace.oid)
+    WHERE nspname || '.' || relname `, typeNamesClause, `
+),
+selected_types(oid) AS (
+    -- collect the OIDs from pg_types which correspond to the selected classes
+    SELECT reltype AS oid
+    FROM selected_classes
+UNION ALL
+    -- as well as any other type names which match our criteria
+    SELECT pg_type.oid
+    FROM pg_type
+    LEFT OUTER JOIN pg_namespace ON (pg_type.typnamespace = pg_namespace.oid)
+    WHERE typname `, typeNamesClause, `
+        OR nspname || '.' || typname `, typeNamesClause, `
+),
+-- this builds a parent/child mapping of objects, allowing us to know
+-- all the child (ie: dependent) types that a parent (type) requires
+-- As can be seen, there are 3 ways this can occur (the last of which
+-- is due to being a composite class, where the composite fields are children)
+pc(parent, child) AS (
+    SELECT parent.oid, parent.typelem
+    FROM pg_type parent
+    WHERE parent.typtype = 'b' AND parent.typelem != 0
+UNION ALL
+    SELECT parent.oid, parent.typbasetype
+    FROM pg_type parent
+    WHERE parent.typtypmod = -1 AND parent.typbasetype != 0
+UNION ALL
+    SELECT pg_type.oid, atttypid
+    FROM pg_attribute
+    INNER JOIN pg_class ON (pg_class.oid = pg_attribute.attrelid)
+    INNER JOIN pg_type ON (pg_type.oid = pg_class.reltype)
+    WHERE NOT attisdropped
+      AND attnum > 0
+),
+-- Now construct a recursive query which includes a 'depth' element.
+-- This is used to ensure that the "youngest" children are registered before
+-- their parents.
+relationships(parent, child, depth) AS (
+    SELECT DISTINCT 0::OID, selected_types.oid, 0
+    FROM selected_types
+UNION ALL
+    SELECT pg_type.oid AS parent, pg_attribute.atttypid AS child, 1
+    FROM selected_classes c
+    inner join pg_type ON (c.reltype = pg_type.oid)
+    inner join pg_attribute on (c.oid = pg_attribute.attrelid)
+UNION ALL
+    SELECT pc.parent, pc.child, relationships.depth + 1
+    FROM pc
+    INNER JOIN relationships ON (pc.parent = relationships.child)
+),
+-- composite fields need to be encapsulated as a couple of arrays to provide the required information for registration
+composite AS (
+    SELECT pg_type.oid, ARRAY_AGG(attname ORDER BY attnum) AS attnames, ARRAY_AGG(atttypid ORDER BY ATTNUM) AS atttypids
+    FROM pg_attribute
+    INNER JOIN pg_class ON (pg_class.oid = pg_attribute.attrelid)
+    INNER JOIN pg_type ON (pg_type.oid = pg_class.reltype)
+    WHERE NOT attisdropped
+      AND attnum > 0
+    GROUP BY pg_type.oid
+)
+-- Bring together this information, showing all the information which might possibly be required
+-- to complete the registration, applying filters to only show the items which relate to the selected
+-- types/classes.
+SELECT typname,
+       pg_namespace.nspname,
+       typtype,
+       typbasetype,
+       typelem,
+       pg_type.oid,`)
+	if supportsMultirange {
+		parts = append(parts, `
+       COALESCE(multirange.rngtypid, 0) AS rngtypid,`)
+	} else {
+		parts = append(parts, `
+       0 AS rngtypid,`)
+	}
+	parts = append(parts, `
+       COALESCE(pg_range.rngsubtype, 0) AS rngsubtype,
+       attnames, atttypids
+    FROM relationships
+    INNER JOIN pg_type ON (pg_type.oid = relationships.child)
+    LEFT OUTER JOIN pg_range ON (pg_type.oid = pg_range.rngtypid)`)
+	if supportsMultirange {
+		parts = append(parts, `
+    LEFT OUTER JOIN pg_range multirange ON (pg_type.oid = multirange.rngmultitypid)`)
+	}
+
+	parts = append(parts, `
+    LEFT OUTER JOIN composite USING (oid)
+    LEFT OUTER JOIN pg_namespace ON (pg_type.typnamespace = pg_namespace.oid)
+    WHERE NOT (typtype = 'b' AND typelem = 0)`)
+	parts = append(parts, `
+    GROUP BY typname, pg_namespace.nspname, typtype, typbasetype, typelem, pg_type.oid, pg_range.rngsubtype,`)
+	if supportsMultirange {
+		parts = append(parts, `
+        multirange.rngtypid,`)
+	}
+	parts = append(parts, `
+        attnames, atttypids
+    ORDER BY MAX(depth) desc, typname;`)
+	return strings.Join(parts, "")
+}
+
+type derivedTypeInfo struct {
+	Oid, Typbasetype, Typelem, Rngsubtype, Rngtypid uint32
+	TypeName, Typtype, NspName                      string
+	Attnames                                        []string
+	Atttypids                                       []uint32
+}
+
+// LoadTypes performs a single (complex) query, returning all the required
+// information to register the named types, as well as any other types directly
+// or indirectly required to complete the registration.
+// The result of this call can be passed into RegisterTypes to complete the process.
+func (c *Conn) LoadTypes(ctx context.Context, typeNames []string) ([]*pgtype.Type, error) {
+	m := c.TypeMap()
+	if typeNames == nil || len(typeNames) == 0 {
+		return nil, fmt.Errorf("No type names were supplied.")
+	}
+
+	// Disregard server version errors. This will result in
+	// the SQL not support recent structures such as multirange
+	serverVersion, _ := serverVersion(c)
+	sql := buildLoadDerivedTypesSQL(serverVersion, typeNames)
+	var rows Rows
+	var err error
+	if typeNames == nil {
+		rows, err = c.Query(ctx, sql, QueryExecModeSimpleProtocol)
+	} else {
+		rows, err = c.Query(ctx, sql, QueryExecModeSimpleProtocol, typeNames)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("While generating load types query: %w", err)
+	}
+	defer rows.Close()
+	result := make([]*pgtype.Type, 0, 100)
+	for rows.Next() {
+		ti := derivedTypeInfo{}
+		err = rows.Scan(&ti.TypeName, &ti.NspName, &ti.Typtype, &ti.Typbasetype, &ti.Typelem, &ti.Oid, &ti.Rngtypid, &ti.Rngsubtype, &ti.Attnames, &ti.Atttypids)
+		if err != nil {
+			return nil, fmt.Errorf("While scanning type information: %w", err)
+		}
+		var type_ *pgtype.Type
+		switch ti.Typtype {
+		case "b": // array
+			dt, ok := m.TypeForOID(ti.Typelem)
+			if !ok {
+				return nil, fmt.Errorf("Array element OID %v not registered while loading pgtype %q", ti.Typelem, ti.TypeName)
+			}
+			type_ = &pgtype.Type{Name: ti.TypeName, OID: ti.Oid, Codec: &pgtype.ArrayCodec{ElementType: dt}}
+		case "c": // composite
+			var fields []pgtype.CompositeCodecField
+			for i, fieldName := range ti.Attnames {
+				dt, ok := m.TypeForOID(ti.Atttypids[i])
+				if !ok {
+					return nil, fmt.Errorf("Unknown field for composite type %q:  field %q (OID %v) is not already registered.", ti.TypeName, fieldName, ti.Atttypids[i])
+				}
+				fields = append(fields, pgtype.CompositeCodecField{Name: fieldName, Type: dt})
+			}
+
+			type_ = &pgtype.Type{Name: ti.TypeName, OID: ti.Oid, Codec: &pgtype.CompositeCodec{Fields: fields}}
+		case "d": // domain
+			dt, ok := m.TypeForOID(ti.Typbasetype)
+			if !ok {
+				return nil, fmt.Errorf("Domain base type OID %v was not already registered, needed for %q", ti.Typbasetype, ti.TypeName)
+			}
+
+			type_ = &pgtype.Type{Name: ti.TypeName, OID: ti.Oid, Codec: dt.Codec}
+		case "e": // enum
+			type_ = &pgtype.Type{Name: ti.TypeName, OID: ti.Oid, Codec: &pgtype.EnumCodec{}}
+		case "r": // range
+			dt, ok := m.TypeForOID(ti.Rngsubtype)
+			if !ok {
+				return nil, fmt.Errorf("Range element OID %v was not already registered, needed for %q", ti.Rngsubtype, ti.TypeName)
+			}
+
+			type_ = &pgtype.Type{Name: ti.TypeName, OID: ti.Oid, Codec: &pgtype.RangeCodec{ElementType: dt}}
+		case "m": // multirange
+			dt, ok := m.TypeForOID(ti.Rngtypid)
+			if !ok {
+				return nil, fmt.Errorf("Multirange element OID %v was not already registered, needed for %q", ti.Rngtypid, ti.TypeName)
+			}
+
+			type_ = &pgtype.Type{Name: ti.TypeName, OID: ti.Oid, Codec: &pgtype.MultirangeCodec{ElementType: dt}}
+		default:
+			return nil, fmt.Errorf("Unknown typtype %q was found while registering %q", ti.Typtype, ti.TypeName)
+		}
+		if type_ != nil {
+			m.RegisterType(type_)
+			if ti.NspName != "" {
+				m.RegisterType(&pgtype.Type{Name: ti.NspName + "." + type_.Name, OID: type_.OID, Codec: type_.Codec})
+			}
+			result = append(result, type_)
+		}
+	}
+	return result, nil
+}
+
+// serverVersion returns the postgresql server version.
+func serverVersion(c *Conn) (int64, error) {
+	serverVersionStr := c.PgConn().ParameterStatus("server_version")
+	serverVersionStr = regexp.MustCompile(`^[0-9]+`).FindString(serverVersionStr)
+	// if not PostgreSQL do nothing
+	if serverVersionStr == "" {
+		return 0, fmt.Errorf("Cannot identify server version in %q", serverVersionStr)
+	}
+
+	version, err := strconv.ParseInt(serverVersionStr, 10, 64)
+	if err != nil {
+		return 0, fmt.Errorf("postgres version parsing failed: %w", err)
+	}
+	return version, nil
+}

derived_types_test.go

@@ -0,0 +1,37 @@
+package pgx_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCompositeCodecTranscodeWithLoadTypes(t *testing.T) {
+	skipCockroachDB(t, "Server does not support composite types (see https://github.com/cockroachdb/cockroach/issues/27792)")
+
+	defaultConnTestRunner.RunTest(context.Background(), t, func(ctx context.Context, t testing.TB, conn *pgx.Conn) {
+		_, err := conn.Exec(ctx, `
+drop type if exists dtype_test;
+drop domain if exists anotheruint64;
+
+create domain anotheruint64 as numeric(20,0);
+create type dtype_test as (
+  a text,
+  b int4,
+  c anotheruint64,
+  d anotheruint64[]
+);`)
+		require.NoError(t, err)
+		defer conn.Exec(ctx, "drop type dtype_test")
+		defer conn.Exec(ctx, "drop domain anotheruint64")
+
+		types, err := conn.LoadTypes(ctx, []string{"dtype_test"})
+		require.NoError(t, err)
+		require.Len(t, types, 3)
+		require.Equal(t, types[0].Name, "anotheruint64")
+		require.Equal(t, types[1].Name, "_anotheruint64")
+		require.Equal(t, types[2].Name, "dtype_test")
+	})
+}

go.sum

@@ -4,10 +4,6 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
 github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
-github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a h1:bbPeKD0xmW/Y25WS6cokEszi5g+S0QxI/d45PkRi7Nk=
-github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
-github.com/jackc/pgservicefile v0.0.0-20231201235250-de7065d80cb9 h1:L0QtFUgDarD7Fpv9jeVMgy/+Ec0mtnmYuImjTz6dtDA=
-github.com/jackc/pgservicefile v0.0.0-20231201235250-de7065d80cb9/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
 github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
 github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
 github.com/jackc/puddle/v2 v2.2.1 h1:RhxXJtFG022u4ibrCSMSiu5aOq1i77R3OHKNJj77OAk=

pgtype/derived_types_test.go

@@ -0,0 +1,58 @@
+package pgtype_test
+
+import (
+	"context"
+	"testing"
+
+	pgx "github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgtype"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDerivedTypes(t *testing.T) {
+	skipCockroachDB(t, "Server does not support composite types (see https://github.com/cockroachdb/cockroach/issues/27792)")
+
+	defaultConnTestRunner.RunTest(context.Background(), t, func(ctx context.Context, t testing.TB, conn *pgx.Conn) {
+		_, err := conn.Exec(ctx, `
+drop type if exists dt_test;
+drop domain if exists dt_uint64;
+
+create domain dt_uint64 as numeric(20,0);
+create type dt_test as (
+	a text,
+    b dt_uint64,
+    c dt_uint64[]
+);`)
+		require.NoError(t, err)
+		defer conn.Exec(ctx, "drop domain dt_uint64")
+		defer conn.Exec(ctx, "drop type dt_test")
+
+		dtypes, err := conn.LoadTypes(ctx, []string{"dt_test"})
+		require.Len(t, dtypes, 3)
+		require.Equal(t, dtypes[0].Name, "dt_uint64")
+		require.Equal(t, dtypes[1].Name, "_dt_uint64")
+		require.Equal(t, dtypes[2].Name, "dt_test")
+		require.NoError(t, err)
+		conn.TypeMap().RegisterTypes(dtypes)
+
+		formats := []struct {
+			name string
+			code int16
+		}{
+			{name: "TextFormat", code: pgx.TextFormatCode},
+			{name: "BinaryFormat", code: pgx.BinaryFormatCode},
+		}
+
+		for _, format := range formats {
+			var a string
+			var b uint64
+			var c *[]uint64
+
+			row := conn.QueryRow(ctx, "select $1::dt_test", pgx.QueryResultFormats{format.code}, pgtype.CompositeFields{"hi", uint64(42), []uint64{10, 20, 30}})
+			err := row.Scan(pgtype.CompositeFields{&a, &b, &c})
+			require.NoError(t, err)
+			require.EqualValuesf(t, "hi", a, "%v", format.name)
+			require.EqualValuesf(t, 42, b, "%v", format.name)
+		}
+	})
+}