switch from github.com/lib/pq to github.com/jackc/pgx/v5HEAD20240905master

lib/pq is out of maintenance for some time now, so switch to the newer
more active library. Looks like it finally stabilized after a long time.

1 files changed, 1395 insertions, 0 deletions

diff --git a/vendor/github.com/jackc/pgx/v5/conn.go b/vendor/github.com/jackc/pgx/v5/conn.go
new file mode 100644
index 0000000..3117214
--- /dev/null
+++ b/vendor/github.com/jackc/pgx/v5/conn.go
@@ -0,0 +1,1395 @@
+package pgx
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/jackc/pgx/v5/internal/sanitize"
+	"github.com/jackc/pgx/v5/internal/stmtcache"
+	"github.com/jackc/pgx/v5/pgconn"
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+// ConnConfig contains all the options used to establish a connection. It must be created by ParseConfig and
+// then it can be modified. A manually initialized ConnConfig will cause ConnectConfig to panic.
+type ConnConfig struct {
+	pgconn.Config
+
+	Tracer QueryTracer
+
+	// Original connection string that was parsed into config.
+	connString string
+
+	// StatementCacheCapacity is maximum size of the statement cache used when executing a query with "cache_statement"
+	// query exec mode.
+	StatementCacheCapacity int
+
+	// DescriptionCacheCapacity is the maximum size of the description cache used when executing a query with
+	// "cache_describe" query exec mode.
+	DescriptionCacheCapacity int
+
+	// DefaultQueryExecMode controls the default mode for executing queries. By default pgx uses the extended protocol
+	// and automatically prepares and caches prepared statements. However, this may be incompatible with proxies such as
+	// PGBouncer. In this case it may be preferable to use QueryExecModeExec or QueryExecModeSimpleProtocol. The same
+	// functionality can be controlled on a per query basis by passing a QueryExecMode as the first query argument.
+	DefaultQueryExecMode QueryExecMode
+
+	createdByParseConfig bool // Used to enforce created by ParseConfig rule.
+}
+
+// ParseConfigOptions contains options that control how a config is built such as getsslpassword.
+type ParseConfigOptions struct {
+	pgconn.ParseConfigOptions
+}
+
+// Copy returns a deep copy of the config that is safe to use and modify.
+// The only exception is the tls.Config:
+// according to the tls.Config docs it must not be modified after creation.
+func (cc *ConnConfig) Copy() *ConnConfig {
+	newConfig := new(ConnConfig)
+	*newConfig = *cc
+	newConfig.Config = *newConfig.Config.Copy()
+	return newConfig
+}
+
+// ConnString returns the connection string as parsed by pgx.ParseConfig into pgx.ConnConfig.
+func (cc *ConnConfig) ConnString() string { return cc.connString }
+
+// Conn is a PostgreSQL connection handle. It is not safe for concurrent usage. Use a connection pool to manage access
+// to multiple database connections from multiple goroutines.
+type Conn struct {
+	pgConn             *pgconn.PgConn
+	config             *ConnConfig // config used when establishing this connection
+	preparedStatements map[string]*pgconn.StatementDescription
+	statementCache     stmtcache.Cache
+	descriptionCache   stmtcache.Cache
+
+	queryTracer    QueryTracer
+	batchTracer    BatchTracer
+	copyFromTracer CopyFromTracer
+	prepareTracer  PrepareTracer
+
+	notifications []*pgconn.Notification
+
+	doneChan   chan struct{}
+	closedChan chan error
+
+	typeMap *pgtype.Map
+
+	wbuf []byte
+	eqb  ExtendedQueryBuilder
+}
+
+// Identifier a PostgreSQL identifier or name. Identifiers can be composed of
+// multiple parts such as ["schema", "table"] or ["table", "column"].
+type Identifier []string
+
+// Sanitize returns a sanitized string safe for SQL interpolation.
+func (ident Identifier) Sanitize() string {
+	parts := make([]string, len(ident))
+	for i := range ident {
+		s := strings.ReplaceAll(ident[i], string([]byte{0}), "")
+		parts[i] = `"` + strings.ReplaceAll(s, `"`, `""`) + `"`
+	}
+	return strings.Join(parts, ".")
+}
+
+var (
+	// ErrNoRows occurs when rows are expected but none are returned.
+	ErrNoRows = errors.New("no rows in result set")
+	// ErrTooManyRows occurs when more rows than expected are returned.
+	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")
+
+// Connect establishes a connection with a PostgreSQL server with a connection string. See
+// pgconn.Connect for details.
+func Connect(ctx context.Context, connString string) (*Conn, error) {
+	connConfig, err := ParseConfig(connString)
+	if err != nil {
+		return nil, err
+	}
+	return connect(ctx, connConfig)
+}
+
+// ConnectWithOptions behaves exactly like Connect with the addition of options. At the present options is only used to
+// provide a GetSSLPassword function.
+func ConnectWithOptions(ctx context.Context, connString string, options ParseConfigOptions) (*Conn, error) {
+	connConfig, err := ParseConfigWithOptions(connString, options)
+	if err != nil {
+		return nil, err
+	}
+	return connect(ctx, connConfig)
+}
+
+// ConnectConfig establishes a connection with a PostgreSQL server with a configuration struct.
+// connConfig must have been created by ParseConfig.
+func ConnectConfig(ctx context.Context, connConfig *ConnConfig) (*Conn, error) {
+	// In general this improves safety. In particular avoid the config.Config.OnNotification mutation from affecting other
+	// connections with the same config. See https://github.com/jackc/pgx/issues/618.
+	connConfig = connConfig.Copy()
+
+	return connect(ctx, connConfig)
+}
+
+// ParseConfigWithOptions behaves exactly as ParseConfig does with the addition of options. At the present options is
+// only used to provide a GetSSLPassword function.
+func ParseConfigWithOptions(connString string, options ParseConfigOptions) (*ConnConfig, error) {
+	config, err := pgconn.ParseConfigWithOptions(connString, options.ParseConfigOptions)
+	if err != nil {
+		return nil, err
+	}
+
+	statementCacheCapacity := 512
+	if s, ok := config.RuntimeParams["statement_cache_capacity"]; ok {
+		delete(config.RuntimeParams, "statement_cache_capacity")
+		n, err := strconv.ParseInt(s, 10, 32)
+		if err != nil {
+			return nil, fmt.Errorf("cannot parse statement_cache_capacity: %w", err)
+		}
+		statementCacheCapacity = int(n)
+	}
+
+	descriptionCacheCapacity := 512
+	if s, ok := config.RuntimeParams["description_cache_capacity"]; ok {
+		delete(config.RuntimeParams, "description_cache_capacity")
+		n, err := strconv.ParseInt(s, 10, 32)
+		if err != nil {
+			return nil, fmt.Errorf("cannot parse description_cache_capacity: %w", err)
+		}
+		descriptionCacheCapacity = int(n)
+	}
+
+	defaultQueryExecMode := QueryExecModeCacheStatement
+	if s, ok := config.RuntimeParams["default_query_exec_mode"]; ok {
+		delete(config.RuntimeParams, "default_query_exec_mode")
+		switch s {
+		case "cache_statement":
+			defaultQueryExecMode = QueryExecModeCacheStatement
+		case "cache_describe":
+			defaultQueryExecMode = QueryExecModeCacheDescribe
+		case "describe_exec":
+			defaultQueryExecMode = QueryExecModeDescribeExec
+		case "exec":
+			defaultQueryExecMode = QueryExecModeExec
+		case "simple_protocol":
+			defaultQueryExecMode = QueryExecModeSimpleProtocol
+		default:
+			return nil, fmt.Errorf("invalid default_query_exec_mode: %s", s)
+		}
+	}
+
+	connConfig := &ConnConfig{
+		Config:                   *config,
+		createdByParseConfig:     true,
+		StatementCacheCapacity:   statementCacheCapacity,
+		DescriptionCacheCapacity: descriptionCacheCapacity,
+		DefaultQueryExecMode:     defaultQueryExecMode,
+		connString:               connString,
+	}
+
+	return connConfig, nil
+}
+
+// ParseConfig creates a ConnConfig from a connection string. ParseConfig handles all options that [pgconn.ParseConfig]
+// does. In addition, it accepts the following options:
+//
+//   - default_query_exec_mode.
+//     Possible values: "cache_statement", "cache_describe", "describe_exec", "exec", and "simple_protocol". See
+//     QueryExecMode constant documentation for the meaning of these values. Default: "cache_statement".
+//
+//   - statement_cache_capacity.
+//     The maximum size of the statement cache used when executing a query with "cache_statement" query exec mode.
+//     Default: 512.
+//
+//   - description_cache_capacity.
+//     The maximum size of the description cache used when executing a query with "cache_describe" query exec mode.
+//     Default: 512.
+func ParseConfig(connString string) (*ConnConfig, error) {
+	return ParseConfigWithOptions(connString, ParseConfigOptions{})
+}
+
+// connect connects to a database. connect takes ownership of config. The caller must not use or access it again.
+func connect(ctx context.Context, config *ConnConfig) (c *Conn, err error) {
+	if connectTracer, ok := config.Tracer.(ConnectTracer); ok {
+		ctx = connectTracer.TraceConnectStart(ctx, TraceConnectStartData{ConnConfig: config})
+		defer func() {
+			connectTracer.TraceConnectEnd(ctx, TraceConnectEndData{Conn: c, Err: err})
+		}()
+	}
+
+	// Default values are set in ParseConfig. Enforce initial creation by ParseConfig rather than setting defaults from
+	// zero values.
+	if !config.createdByParseConfig {
+		panic("config must be created by ParseConfig")
+	}
+
+	c = &Conn{
+		config:      config,
+		typeMap:     pgtype.NewMap(),
+		queryTracer: config.Tracer,
+	}
+
+	if t, ok := c.queryTracer.(BatchTracer); ok {
+		c.batchTracer = t
+	}
+	if t, ok := c.queryTracer.(CopyFromTracer); ok {
+		c.copyFromTracer = t
+	}
+	if t, ok := c.queryTracer.(PrepareTracer); ok {
+		c.prepareTracer = t
+	}
+
+	// Only install pgx notification system if no other callback handler is present.
+	if config.Config.OnNotification == nil {
+		config.Config.OnNotification = c.bufferNotifications
+	}
+
+	c.pgConn, err = pgconn.ConnectConfig(ctx, &config.Config)
+	if err != nil {
+		return nil, err
+	}
+
+	c.preparedStatements = make(map[string]*pgconn.StatementDescription)
+	c.doneChan = make(chan struct{})
+	c.closedChan = make(chan error)
+	c.wbuf = make([]byte, 0, 1024)
+
+	if c.config.StatementCacheCapacity > 0 {
+		c.statementCache = stmtcache.NewLRUCache(c.config.StatementCacheCapacity)
+	}
+
+	if c.config.DescriptionCacheCapacity > 0 {
+		c.descriptionCache = stmtcache.NewLRUCache(c.config.DescriptionCacheCapacity)
+	}
+
+	return c, nil
+}
+
+// Close closes a connection. It is safe to call Close on an already closed
+// connection.
+func (c *Conn) Close(ctx context.Context) error {
+	if c.IsClosed() {
+		return nil
+	}
+
+	err := c.pgConn.Close(ctx)
+	return err
+}
+
+// Prepare creates a prepared statement with name and sql. sql can contain placeholders for bound parameters. These
+// placeholders are referenced positionally as $1, $2, etc. name can be used instead of sql with Query, QueryRow, and
+// Exec to execute the statement. It can also be used with Batch.Queue.
+//
+// The underlying PostgreSQL identifier for the prepared statement will be name if name != sql or a digest of sql if
+// name == sql.
+//
+// Prepare is idempotent; i.e. it is safe to call Prepare multiple times with the same name and sql arguments. This
+// allows a code path to Prepare and Query/Exec without concern for if the statement has already been prepared.
+func (c *Conn) Prepare(ctx context.Context, name, sql string) (sd *pgconn.StatementDescription, err error) {
+	if c.prepareTracer != nil {
+		ctx = c.prepareTracer.TracePrepareStart(ctx, c, TracePrepareStartData{Name: name, SQL: sql})
+	}
+
+	if name != "" {
+		var ok bool
+		if sd, ok = c.preparedStatements[name]; ok && sd.SQL == sql {
+			if c.prepareTracer != nil {
+				c.prepareTracer.TracePrepareEnd(ctx, c, TracePrepareEndData{AlreadyPrepared: true})
+			}
+			return sd, nil
+		}
+	}
+
+	if c.prepareTracer != nil {
+		defer func() {
+			c.prepareTracer.TracePrepareEnd(ctx, c, TracePrepareEndData{Err: err})
+		}()
+	}
+
+	var psName, psKey string
+	if name == sql {
+		digest := sha256.Sum256([]byte(sql))
+		psName = "stmt_" + hex.EncodeToString(digest[0:24])
+		psKey = sql
+	} else {
+		psName = name
+		psKey = name
+	}
+
+	sd, err = c.pgConn.Prepare(ctx, psName, sql, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	if psKey != "" {
+		c.preparedStatements[psKey] = sd
+	}
+
+	return sd, nil
+}
+
+// Deallocate releases a prepared statement. Calling Deallocate on a non-existent prepared statement will succeed.
+func (c *Conn) Deallocate(ctx context.Context, name string) error {
+	var psName string
+	sd := c.preparedStatements[name]
+	if sd != nil {
+		psName = sd.Name
+	} else {
+		psName = name
+	}
+
+	err := c.pgConn.Deallocate(ctx, psName)
+	if err != nil {
+		return err
+	}
+
+	if sd != nil {
+		delete(c.preparedStatements, name)
+	}
+
+	return nil
+}
+
+// DeallocateAll releases all previously prepared statements from the server and client, where it also resets the statement and description cache.
+func (c *Conn) DeallocateAll(ctx context.Context) error {
+	c.preparedStatements = map[string]*pgconn.StatementDescription{}
+	if c.config.StatementCacheCapacity > 0 {
+		c.statementCache = stmtcache.NewLRUCache(c.config.StatementCacheCapacity)
+	}
+	if c.config.DescriptionCacheCapacity > 0 {
+		c.descriptionCache = stmtcache.NewLRUCache(c.config.DescriptionCacheCapacity)
+	}
+	_, err := c.pgConn.Exec(ctx, "deallocate all").ReadAll()
+	return err
+}
+
+func (c *Conn) bufferNotifications(_ *pgconn.PgConn, n *pgconn.Notification) {
+	c.notifications = append(c.notifications, n)
+}
+
+// WaitForNotification waits for a PostgreSQL notification. It wraps the underlying pgconn notification system in a
+// slightly more convenient form.
+func (c *Conn) WaitForNotification(ctx context.Context) (*pgconn.Notification, error) {
+	var n *pgconn.Notification
+
+	// Return already received notification immediately
+	if len(c.notifications) > 0 {
+		n = c.notifications[0]
+		c.notifications = c.notifications[1:]
+		return n, nil
+	}
+
+	err := c.pgConn.WaitForNotification(ctx)
+	if len(c.notifications) > 0 {
+		n = c.notifications[0]
+		c.notifications = c.notifications[1:]
+	}
+	return n, err
+}
+
+// IsClosed reports if the connection has been closed.
+func (c *Conn) IsClosed() bool {
+	return c.pgConn.IsClosed()
+}
+
+func (c *Conn) die(err error) {
+	if c.IsClosed() {
+		return
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // force immediate hard cancel
+	c.pgConn.Close(ctx)
+}
+
+func quoteIdentifier(s string) string {
+	return `"` + strings.ReplaceAll(s, `"`, `""`) + `"`
+}
+
+// Ping delegates to the underlying *pgconn.PgConn.Ping.
+func (c *Conn) Ping(ctx context.Context) error {
+	return c.pgConn.Ping(ctx)
+}
+
+// PgConn returns the underlying *pgconn.PgConn. This is an escape hatch method that allows lower level access to the
+// PostgreSQL connection than pgx exposes.
+//
+// It is strongly recommended that the connection be idle (no in-progress queries) before the underlying *pgconn.PgConn
+// is used and the connection must be returned to the same state before any *pgx.Conn methods are again used.
+func (c *Conn) PgConn() *pgconn.PgConn { return c.pgConn }
+
+// TypeMap returns the connection info used for this connection.
+func (c *Conn) TypeMap() *pgtype.Map { return c.typeMap }
+
+// Config returns a copy of config that was used to establish this connection.
+func (c *Conn) Config() *ConnConfig { return c.config.Copy() }
+
+// Exec executes sql. sql can be either a prepared statement name or an SQL string. arguments should be referenced
+// positionally from the sql string as $1, $2, etc.
+func (c *Conn) Exec(ctx context.Context, sql string, arguments ...any) (pgconn.CommandTag, error) {
+	if c.queryTracer != nil {
+		ctx = c.queryTracer.TraceQueryStart(ctx, c, TraceQueryStartData{SQL: sql, Args: arguments})
+	}
+
+	if err := c.deallocateInvalidatedCachedStatements(ctx); err != nil {
+		return pgconn.CommandTag{}, err
+	}
+
+	commandTag, err := c.exec(ctx, sql, arguments...)
+
+	if c.queryTracer != nil {
+		c.queryTracer.TraceQueryEnd(ctx, c, TraceQueryEndData{CommandTag: commandTag, Err: err})
+	}
+
+	return commandTag, err
+}
+
+func (c *Conn) exec(ctx context.Context, sql string, arguments ...any) (commandTag pgconn.CommandTag, err error) {
+	mode := c.config.DefaultQueryExecMode
+	var queryRewriter QueryRewriter
+
+optionLoop:
+	for len(arguments) > 0 {
+		switch arg := arguments[0].(type) {
+		case QueryExecMode:
+			mode = arg
+			arguments = arguments[1:]
+		case QueryRewriter:
+			queryRewriter = arg
+			arguments = arguments[1:]
+		default:
+			break optionLoop
+		}
+	}
+
+	if queryRewriter != nil {
+		sql, arguments, err = queryRewriter.RewriteQuery(ctx, c, sql, arguments)
+		if err != nil {
+			return pgconn.CommandTag{}, fmt.Errorf("rewrite query failed: %w", err)
+		}
+	}
+
+	// Always use simple protocol when there are no arguments.
+	if len(arguments) == 0 {
+		mode = QueryExecModeSimpleProtocol
+	}
+
+	if sd, ok := c.preparedStatements[sql]; ok {
+		return c.execPrepared(ctx, sd, arguments)
+	}
+
+	switch mode {
+	case QueryExecModeCacheStatement:
+		if c.statementCache == nil {
+			return pgconn.CommandTag{}, errDisabledStatementCache
+		}
+		sd := c.statementCache.Get(sql)
+		if sd == nil {
+			sd, err = c.Prepare(ctx, stmtcache.StatementName(sql), sql)
+			if err != nil {
+				return pgconn.CommandTag{}, err
+			}
+			c.statementCache.Put(sd)
+		}
+
+		return c.execPrepared(ctx, sd, arguments)
+	case QueryExecModeCacheDescribe:
+		if c.descriptionCache == nil {
+			return pgconn.CommandTag{}, errDisabledDescriptionCache
+		}
+		sd := c.descriptionCache.Get(sql)
+		if sd == nil {
+			sd, err = c.Prepare(ctx, "", sql)
+			if err != nil {
+				return pgconn.CommandTag{}, err
+			}
+			c.descriptionCache.Put(sd)
+		}
+
+		return c.execParams(ctx, sd, arguments)
+	case QueryExecModeDescribeExec:
+		sd, err := c.Prepare(ctx, "", sql)
+		if err != nil {
+			return pgconn.CommandTag{}, err
+		}
+		return c.execPrepared(ctx, sd, arguments)
+	case QueryExecModeExec:
+		return c.execSQLParams(ctx, sql, arguments)
+	case QueryExecModeSimpleProtocol:
+		return c.execSimpleProtocol(ctx, sql, arguments)
+	default:
+		return pgconn.CommandTag{}, fmt.Errorf("unknown QueryExecMode: %v", mode)
+	}
+}
+
+func (c *Conn) execSimpleProtocol(ctx context.Context, sql string, arguments []any) (commandTag pgconn.CommandTag, err error) {
+	if len(arguments) > 0 {
+		sql, err = c.sanitizeForSimpleQuery(sql, arguments...)
+		if err != nil {
+			return pgconn.CommandTag{}, err
+		}
+	}
+
+	mrr := c.pgConn.Exec(ctx, sql)
+	for mrr.NextResult() {
+		commandTag, _ = mrr.ResultReader().Close()
+	}
+	err = mrr.Close()
+	return commandTag, err
+}
+
+func (c *Conn) execParams(ctx context.Context, sd *pgconn.StatementDescription, arguments []any) (pgconn.CommandTag, error) {
+	err := c.eqb.Build(c.typeMap, sd, arguments)
+	if err != nil {
+		return pgconn.CommandTag{}, err
+	}
+
+	result := c.pgConn.ExecParams(ctx, sd.SQL, c.eqb.ParamValues, sd.ParamOIDs, c.eqb.ParamFormats, c.eqb.ResultFormats).Read()
+	c.eqb.reset() // Allow c.eqb internal memory to be GC'ed as soon as possible.
+	return result.CommandTag, result.Err
+}
+
+func (c *Conn) execPrepared(ctx context.Context, sd *pgconn.StatementDescription, arguments []any) (pgconn.CommandTag, error) {
+	err := c.eqb.Build(c.typeMap, sd, arguments)
+	if err != nil {
+		return pgconn.CommandTag{}, err
+	}
+
+	result := c.pgConn.ExecPrepared(ctx, sd.Name, c.eqb.ParamValues, c.eqb.ParamFormats, c.eqb.ResultFormats).Read()
+	c.eqb.reset() // Allow c.eqb internal memory to be GC'ed as soon as possible.
+	return result.CommandTag, result.Err
+}
+
+type unknownArgumentTypeQueryExecModeExecError struct {
+	arg any
+}
+
+func (e *unknownArgumentTypeQueryExecModeExecError) Error() string {
+	return fmt.Sprintf("cannot use unregistered type %T as query argument in QueryExecModeExec", e.arg)
+}
+
+func (c *Conn) execSQLParams(ctx context.Context, sql string, args []any) (pgconn.CommandTag, error) {
+	err := c.eqb.Build(c.typeMap, nil, args)
+	if err != nil {
+		return pgconn.CommandTag{}, err
+	}
+
+	result := c.pgConn.ExecParams(ctx, sql, c.eqb.ParamValues, nil, c.eqb.ParamFormats, c.eqb.ResultFormats).Read()
+	c.eqb.reset() // Allow c.eqb internal memory to be GC'ed as soon as possible.
+	return result.CommandTag, result.Err
+}
+
+func (c *Conn) getRows(ctx context.Context, sql string, args []any) *baseRows {
+	r := &baseRows{}
+
+	r.ctx = ctx
+	r.queryTracer = c.queryTracer
+	r.typeMap = c.typeMap
+	r.startTime = time.Now()
+	r.sql = sql
+	r.args = args
+	r.conn = c
+
+	return r
+}
+
+type QueryExecMode int32
+
+const (
+	_ QueryExecMode = iota
+
+	// Automatically prepare and cache statements. This uses the extended protocol. Queries are executed in a single round
+	// trip after the statement is cached. This is the default. If the database schema is modified or the search_path is
+	// changed after a statement is cached then the first execution of a previously cached query may fail. e.g. If the
+	// number of columns returned by a "SELECT *" changes or the type of a column is changed.
+	QueryExecModeCacheStatement
+
+	// Cache statement descriptions (i.e. argument and result types) and assume they do not change. This uses the extended
+	// protocol. Queries are executed in a single round trip after the description is cached. If the database schema is
+	// modified or the search_path is changed after a statement is cached then the first execution of a previously cached
+	// query may fail. e.g. If the number of columns returned by a "SELECT *" changes or the type of a column is changed.
+	QueryExecModeCacheDescribe
+
+	// Get the statement description on every execution. This uses the extended protocol. Queries require two round trips
+	// to execute. It does not use named prepared statements. But it does use the unnamed prepared statement to get the
+	// statement description on the first round trip and then uses it to execute the query on the second round trip. This
+	// may cause problems with connection poolers that switch the underlying connection between round trips. It is safe
+	// even when the database schema is modified concurrently.
+	QueryExecModeDescribeExec
+
+	// Assume the PostgreSQL query parameter types based on the Go type of the arguments. This uses the extended protocol
+	// with text formatted parameters and results. Queries are executed in a single round trip. Type mappings can be
+	// registered with pgtype.Map.RegisterDefaultPgType. Queries will be rejected that have arguments that are
+	// unregistered or ambiguous. e.g. A map[string]string may have the PostgreSQL type json or hstore. Modes that know
+	// the PostgreSQL type can use a map[string]string directly as an argument. This mode cannot.
+	QueryExecModeExec
+
+	// Use the simple protocol. Assume the PostgreSQL query parameter types based on the Go type of the arguments.
+	// Queries are executed in a single round trip. Type mappings can be registered with
+	// pgtype.Map.RegisterDefaultPgType. Queries will be rejected that have arguments that are unregistered or ambiguous.
+	// e.g. A map[string]string may have the PostgreSQL type json or hstore. Modes that know the PostgreSQL type can use
+	// a map[string]string directly as an argument. This mode cannot.
+	//
+	// QueryExecModeSimpleProtocol should have the user application visible behavior as QueryExecModeExec with minor
+	// exceptions such as behavior when multiple result returning queries are erroneously sent in a single string.
+	//
+	// QueryExecModeSimpleProtocol uses client side parameter interpolation. All values are quoted and escaped. Prefer
+	// QueryExecModeExec over QueryExecModeSimpleProtocol whenever possible. In general QueryExecModeSimpleProtocol
+	// should only be used if connecting to a proxy server, connection pool server, or non-PostgreSQL server that does
+	// not support the extended protocol.
+	QueryExecModeSimpleProtocol
+)
+
+func (m QueryExecMode) String() string {
+	switch m {
+	case QueryExecModeCacheStatement:
+		return "cache statement"
+	case QueryExecModeCacheDescribe:
+		return "cache describe"
+	case QueryExecModeDescribeExec:
+		return "describe exec"
+	case QueryExecModeExec:
+		return "exec"
+	case QueryExecModeSimpleProtocol:
+		return "simple protocol"
+	default:
+		return "invalid"
+	}
+}
+
+// QueryResultFormats controls the result format (text=0, binary=1) of a query by result column position.
+type QueryResultFormats []int16
+
+// QueryResultFormatsByOID controls the result format (text=0, binary=1) of a query by the result column OID.
+type QueryResultFormatsByOID map[uint32]int16
+
+// QueryRewriter rewrites a query when used as the first arguments to a query method.
+type QueryRewriter interface {
+	RewriteQuery(ctx context.Context, conn *Conn, sql string, args []any) (newSQL string, newArgs []any, err error)
+}
+
+// Query sends a query to the server and returns a Rows to read the results. Only errors encountered sending the query
+// and initializing Rows will be returned. Err() on the returned Rows must be checked after the Rows is closed to
+// determine if the query executed successfully.
+//
+// The returned Rows must be closed before the connection can be used again. It is safe to attempt to read from the
+// returned Rows even if an error is returned. The error will be the available in rows.Err() after rows are closed. It
+// is allowed to ignore the error returned from Query and handle it in Rows.
+//
+// It is possible for a call of FieldDescriptions on the returned Rows to return nil even if the Query call did not
+// return an error.
+//
+// It is possible for a query to return one or more rows before encountering an error. In most cases the rows should be
+// collected before processing rather than processed while receiving each row. This avoids the possibility of the
+// application processing rows from a query that the server rejected. The CollectRows function is useful here.
+//
+// An implementor of QueryRewriter may be passed as the first element of args. It can rewrite the sql and change or
+// replace args. For example, NamedArgs is QueryRewriter that implements named arguments.
+//
+// For extra control over how the query is executed, the types QueryExecMode, QueryResultFormats, and
+// QueryResultFormatsByOID may be used as the first args to control exactly how the query is executed. This is rarely
+// needed. See the documentation for those types for details.
+func (c *Conn) Query(ctx context.Context, sql string, args ...any) (Rows, error) {
+	if c.queryTracer != nil {
+		ctx = c.queryTracer.TraceQueryStart(ctx, c, TraceQueryStartData{SQL: sql, Args: args})
+	}
+
+	if err := c.deallocateInvalidatedCachedStatements(ctx); err != nil {
+		if c.queryTracer != nil {
+			c.queryTracer.TraceQueryEnd(ctx, c, TraceQueryEndData{Err: err})
+		}
+		return &baseRows{err: err, closed: true}, err
+	}
+
+	var resultFormats QueryResultFormats
+	var resultFormatsByOID QueryResultFormatsByOID
+	mode := c.config.DefaultQueryExecMode
+	var queryRewriter QueryRewriter
+
+optionLoop:
+	for len(args) > 0 {
+		switch arg := args[0].(type) {
+		case QueryResultFormats:
+			resultFormats = arg
+			args = args[1:]
+		case QueryResultFormatsByOID:
+			resultFormatsByOID = arg
+			args = args[1:]
+		case QueryExecMode:
+			mode = arg
+			args = args[1:]
+		case QueryRewriter:
+			queryRewriter = arg
+			args = args[1:]
+		default:
+			break optionLoop
+		}
+	}
+
+	if queryRewriter != nil {
+		var err error
+		originalSQL := sql
+		originalArgs := args
+		sql, args, err = queryRewriter.RewriteQuery(ctx, c, sql, args)
+		if err != nil {
+			rows := c.getRows(ctx, originalSQL, originalArgs)
+			err = fmt.Errorf("rewrite query failed: %w", err)
+			rows.fatal(err)
+			return rows, err
+		}
+	}
+
+	// Bypass any statement caching.
+	if sql == "" {
+		mode = QueryExecModeSimpleProtocol
+	}
+
+	c.eqb.reset()
+	rows := c.getRows(ctx, sql, args)
+
+	var err error
+	sd, explicitPreparedStatement := c.preparedStatements[sql]
+	if sd != nil || mode == QueryExecModeCacheStatement || mode == QueryExecModeCacheDescribe || mode == QueryExecModeDescribeExec {
+		if sd == nil {
+			sd, err = c.getStatementDescription(ctx, mode, sql)
+			if err != nil {
+				rows.fatal(err)
+				return rows, err
+			}
+		}
+
+		if len(sd.ParamOIDs) != len(args) {
+			rows.fatal(fmt.Errorf("expected %d arguments, got %d", len(sd.ParamOIDs), len(args)))
+			return rows, rows.err
+		}
+
+		rows.sql = sd.SQL
+
+		err = c.eqb.Build(c.typeMap, sd, args)
+		if err != nil {
+			rows.fatal(err)
+			return rows, rows.err
+		}
+
+		if resultFormatsByOID != nil {
+			resultFormats = make([]int16, len(sd.Fields))
+			for i := range resultFormats {
+				resultFormats[i] = resultFormatsByOID[uint32(sd.Fields[i].DataTypeOID)]
+			}
+		}
+
+		if resultFormats == nil {
+			resultFormats = c.eqb.ResultFormats
+		}
+
+		if !explicitPreparedStatement && mode == QueryExecModeCacheDescribe {
+			rows.resultReader = c.pgConn.ExecParams(ctx, sql, c.eqb.ParamValues, sd.ParamOIDs, c.eqb.ParamFormats, resultFormats)
+		} else {
+			rows.resultReader = c.pgConn.ExecPrepared(ctx, sd.Name, c.eqb.ParamValues, c.eqb.ParamFormats, resultFormats)
+		}
+	} else if mode == QueryExecModeExec {
+		err := c.eqb.Build(c.typeMap, nil, args)
+		if err != nil {
+			rows.fatal(err)
+			return rows, rows.err
+		}
+
+		rows.resultReader = c.pgConn.ExecParams(ctx, sql, c.eqb.ParamValues, nil, c.eqb.ParamFormats, c.eqb.ResultFormats)
+	} else if mode == QueryExecModeSimpleProtocol {
+		sql, err = c.sanitizeForSimpleQuery(sql, args...)
+		if err != nil {
+			rows.fatal(err)
+			return rows, err
+		}
+
+		mrr := c.pgConn.Exec(ctx, sql)
+		if mrr.NextResult() {
+			rows.resultReader = mrr.ResultReader()
+			rows.multiResultReader = mrr
+		} else {
+			err = mrr.Close()
+			rows.fatal(err)
+			return rows, err
+		}
+
+		return rows, nil
+	} else {
+		err = fmt.Errorf("unknown QueryExecMode: %v", mode)
+		rows.fatal(err)
+		return rows, rows.err
+	}
+
+	c.eqb.reset() // Allow c.eqb internal memory to be GC'ed as soon as possible.
+
+	return rows, rows.err
+}
+
+// getStatementDescription returns the statement description of the sql query
+// according to the given mode.
+//
+// If the mode is one that doesn't require to know the param and result OIDs
+// then nil is returned without error.
+func (c *Conn) getStatementDescription(
+	ctx context.Context,
+	mode QueryExecMode,
+	sql string,
+) (sd *pgconn.StatementDescription, err error) {
+
+	switch mode {
+	case QueryExecModeCacheStatement:
+		if c.statementCache == nil {
+			return nil, errDisabledStatementCache
+		}
+		sd = c.statementCache.Get(sql)
+		if sd == nil {
+			sd, err = c.Prepare(ctx, stmtcache.StatementName(sql), sql)
+			if err != nil {
+				return nil, err
+			}
+			c.statementCache.Put(sd)
+		}
+	case QueryExecModeCacheDescribe:
+		if c.descriptionCache == nil {
+			return nil, errDisabledDescriptionCache
+		}
+		sd = c.descriptionCache.Get(sql)
+		if sd == nil {
+			sd, err = c.Prepare(ctx, "", sql)
+			if err != nil {
+				return nil, err
+			}
+			c.descriptionCache.Put(sd)
+		}
+	case QueryExecModeDescribeExec:
+		return c.Prepare(ctx, "", sql)
+	}
+	return sd, err
+}
+
+// QueryRow is a convenience wrapper over Query. Any error that occurs while
+// querying is deferred until calling Scan on the returned Row. That Row will
+// error with ErrNoRows if no rows are returned.
+func (c *Conn) QueryRow(ctx context.Context, sql string, args ...any) Row {
+	rows, _ := c.Query(ctx, sql, args...)
+	return (*connRow)(rows.(*baseRows))
+}
+
+// SendBatch sends all queued queries to the server at once. All queries are run in an implicit transaction unless
+// explicit transaction control statements are executed. The returned BatchResults must be closed before the connection
+// is used again.
+func (c *Conn) SendBatch(ctx context.Context, b *Batch) (br BatchResults) {
+	if c.batchTracer != nil {
+		ctx = c.batchTracer.TraceBatchStart(ctx, c, TraceBatchStartData{Batch: b})
+		defer func() {
+			err := br.(interface{ earlyError() error }).earlyError()
+			if err != nil {
+				c.batchTracer.TraceBatchEnd(ctx, c, TraceBatchEndData{Err: err})
+			}
+		}()
+	}
+
+	if err := c.deallocateInvalidatedCachedStatements(ctx); err != nil {
+		return &batchResults{ctx: ctx, conn: c, err: err}
+	}
+
+	for _, bi := range b.QueuedQueries {
+		var queryRewriter QueryRewriter
+		sql := bi.SQL
+		arguments := bi.Arguments
+
+	optionLoop:
+		for len(arguments) > 0 {
+			// Update Batch.Queue function comment when additional options are implemented
+			switch arg := arguments[0].(type) {
+			case QueryRewriter:
+				queryRewriter = arg
+				arguments = arguments[1:]
+			default:
+				break optionLoop
+			}
+		}
+
+		if queryRewriter != nil {
+			var err error
+			sql, arguments, err = queryRewriter.RewriteQuery(ctx, c, sql, arguments)
+			if err != nil {
+				return &batchResults{ctx: ctx, conn: c, err: fmt.Errorf("rewrite query failed: %w", err)}
+			}
+		}
+
+		bi.SQL = sql
+		bi.Arguments = arguments
+	}
+
+	// TODO: changing mode per batch? Update Batch.Queue function comment when implemented
+	mode := c.config.DefaultQueryExecMode
+	if mode == QueryExecModeSimpleProtocol {
+		return c.sendBatchQueryExecModeSimpleProtocol(ctx, b)
+	}
+
+	// All other modes use extended protocol and thus can use prepared statements.
+	for _, bi := range b.QueuedQueries {
+		if sd, ok := c.preparedStatements[bi.SQL]; ok {
+			bi.sd = sd
+		}
+	}
+
+	switch mode {
+	case QueryExecModeExec:
+		return c.sendBatchQueryExecModeExec(ctx, b)
+	case QueryExecModeCacheStatement:
+		return c.sendBatchQueryExecModeCacheStatement(ctx, b)
+	case QueryExecModeCacheDescribe:
+		return c.sendBatchQueryExecModeCacheDescribe(ctx, b)
+	case QueryExecModeDescribeExec:
+		return c.sendBatchQueryExecModeDescribeExec(ctx, b)
+	default:
+		panic("unknown QueryExecMode")
+	}
+}
+
+func (c *Conn) sendBatchQueryExecModeSimpleProtocol(ctx context.Context, b *Batch) *batchResults {
+	var sb strings.Builder
+	for i, bi := range b.QueuedQueries {
+		if i > 0 {
+			sb.WriteByte(';')
+		}
+		sql, err := c.sanitizeForSimpleQuery(bi.SQL, bi.Arguments...)
+		if err != nil {
+			return &batchResults{ctx: ctx, conn: c, err: err}
+		}
+		sb.WriteString(sql)
+	}
+	mrr := c.pgConn.Exec(ctx, sb.String())
+	return &batchResults{
+		ctx:   ctx,
+		conn:  c,
+		mrr:   mrr,
+		b:     b,
+		qqIdx: 0,
+	}
+}
+
+func (c *Conn) sendBatchQueryExecModeExec(ctx context.Context, b *Batch) *batchResults {
+	batch := &pgconn.Batch{}
+
+	for _, bi := range b.QueuedQueries {
+		sd := bi.sd
+		if sd != nil {
+			err := c.eqb.Build(c.typeMap, sd, bi.Arguments)
+			if err != nil {
+				return &batchResults{ctx: ctx, conn: c, err: err}
+			}
+
+			batch.ExecPrepared(sd.Name, c.eqb.ParamValues, c.eqb.ParamFormats, c.eqb.ResultFormats)
+		} else {
+			err := c.eqb.Build(c.typeMap, nil, bi.Arguments)
+			if err != nil {
+				return &batchResults{ctx: ctx, conn: c, err: err}
+			}
+			batch.ExecParams(bi.SQL, c.eqb.ParamValues, nil, c.eqb.ParamFormats, c.eqb.ResultFormats)
+		}
+	}
+
+	c.eqb.reset() // Allow c.eqb internal memory to be GC'ed as soon as possible.
+
+	mrr := c.pgConn.ExecBatch(ctx, batch)
+
+	return &batchResults{
+		ctx:   ctx,
+		conn:  c,
+		mrr:   mrr,
+		b:     b,
+		qqIdx: 0,
+	}
+}
+
+func (c *Conn) sendBatchQueryExecModeCacheStatement(ctx context.Context, b *Batch) (pbr *pipelineBatchResults) {
+	if c.statementCache == nil {
+		return &pipelineBatchResults{ctx: ctx, conn: c, err: errDisabledStatementCache, closed: true}
+	}
+
+	distinctNewQueries := []*pgconn.StatementDescription{}
+	distinctNewQueriesIdxMap := make(map[string]int)
+
+	for _, bi := range b.QueuedQueries {
+		if bi.sd == nil {
+			sd := c.statementCache.Get(bi.SQL)
+			if sd != nil {
+				bi.sd = sd
+			} else {
+				if idx, present := distinctNewQueriesIdxMap[bi.SQL]; present {
+					bi.sd = distinctNewQueries[idx]
+				} else {
+					sd = &pgconn.StatementDescription{
+						Name: stmtcache.StatementName(bi.SQL),
+						SQL:  bi.SQL,
+					}
+					distinctNewQueriesIdxMap[sd.SQL] = len(distinctNewQueries)
+					distinctNewQueries = append(distinctNewQueries, sd)
+					bi.sd = sd
+				}
+			}
+		}
+	}
+
+	return c.sendBatchExtendedWithDescription(ctx, b, distinctNewQueries, c.statementCache)
+}
+
+func (c *Conn) sendBatchQueryExecModeCacheDescribe(ctx context.Context, b *Batch) (pbr *pipelineBatchResults) {
+	if c.descriptionCache == nil {
+		return &pipelineBatchResults{ctx: ctx, conn: c, err: errDisabledDescriptionCache, closed: true}
+	}
+
+	distinctNewQueries := []*pgconn.StatementDescription{}
+	distinctNewQueriesIdxMap := make(map[string]int)
+
+	for _, bi := range b.QueuedQueries {
+		if bi.sd == nil {
+			sd := c.descriptionCache.Get(bi.SQL)
+			if sd != nil {
+				bi.sd = sd
+			} else {
+				if idx, present := distinctNewQueriesIdxMap[bi.SQL]; present {
+					bi.sd = distinctNewQueries[idx]
+				} else {
+					sd = &pgconn.StatementDescription{
+						SQL: bi.SQL,
+					}
+					distinctNewQueriesIdxMap[sd.SQL] = len(distinctNewQueries)
+					distinctNewQueries = append(distinctNewQueries, sd)
+					bi.sd = sd
+				}
+			}
+		}
+	}
+
+	return c.sendBatchExtendedWithDescription(ctx, b, distinctNewQueries, c.descriptionCache)
+}
+
+func (c *Conn) sendBatchQueryExecModeDescribeExec(ctx context.Context, b *Batch) (pbr *pipelineBatchResults) {
+	distinctNewQueries := []*pgconn.StatementDescription{}
+	distinctNewQueriesIdxMap := make(map[string]int)
+
+	for _, bi := range b.QueuedQueries {
+		if bi.sd == nil {
+			if idx, present := distinctNewQueriesIdxMap[bi.SQL]; present {
+				bi.sd = distinctNewQueries[idx]
+			} else {
+				sd := &pgconn.StatementDescription{
+					SQL: bi.SQL,
+				}
+				distinctNewQueriesIdxMap[sd.SQL] = len(distinctNewQueries)
+				distinctNewQueries = append(distinctNewQueries, sd)
+				bi.sd = sd
+			}
+		}
+	}
+
+	return c.sendBatchExtendedWithDescription(ctx, b, distinctNewQueries, nil)
+}
+
+func (c *Conn) sendBatchExtendedWithDescription(ctx context.Context, b *Batch, distinctNewQueries []*pgconn.StatementDescription, sdCache stmtcache.Cache) (pbr *pipelineBatchResults) {
+	pipeline := c.pgConn.StartPipeline(ctx)
+	defer func() {
+		if pbr != nil && pbr.err != nil {
+			pipeline.Close()
+		}
+	}()
+
+	// Prepare any needed queries
+	if len(distinctNewQueries) > 0 {
+		for _, sd := range distinctNewQueries {
+			pipeline.SendPrepare(sd.Name, sd.SQL, nil)
+		}
+
+		err := pipeline.Sync()
+		if err != nil {
+			return &pipelineBatchResults{ctx: ctx, conn: c, err: err, closed: true}
+		}
+
+		for _, sd := range distinctNewQueries {
+			results, err := pipeline.GetResults()
+			if err != nil {
+				return &pipelineBatchResults{ctx: ctx, conn: c, err: err, closed: true}
+			}
+
+			resultSD, ok := results.(*pgconn.StatementDescription)
+			if !ok {
+				return &pipelineBatchResults{ctx: ctx, conn: c, err: fmt.Errorf("expected statement description, got %T", results), closed: true}
+			}
+
+			// Fill in the previously empty / pending statement descriptions.
+			sd.ParamOIDs = resultSD.ParamOIDs
+			sd.Fields = resultSD.Fields
+		}
+
+		results, err := pipeline.GetResults()
+		if err != nil {
+			return &pipelineBatchResults{ctx: ctx, conn: c, err: err, closed: true}
+		}
+
+		_, ok := results.(*pgconn.PipelineSync)
+		if !ok {
+			return &pipelineBatchResults{ctx: ctx, conn: c, err: fmt.Errorf("expected sync, got %T", results), closed: true}
+		}
+	}
+
+	// Put all statements into the cache. It's fine if it overflows because HandleInvalidated will clean them up later.
+	if sdCache != nil {
+		for _, sd := range distinctNewQueries {
+			sdCache.Put(sd)
+		}
+	}
+
+	// Queue the queries.
+	for _, bi := range b.QueuedQueries {
+		err := c.eqb.Build(c.typeMap, bi.sd, bi.Arguments)
+		if err != nil {
+			// we wrap the error so we the user can understand which query failed inside the batch
+			err = fmt.Errorf("error building query %s: %w", bi.SQL, err)
+			return &pipelineBatchResults{ctx: ctx, conn: c, err: err, closed: true}
+		}
+
+		if bi.sd.Name == "" {
+			pipeline.SendQueryParams(bi.sd.SQL, c.eqb.ParamValues, bi.sd.ParamOIDs, c.eqb.ParamFormats, c.eqb.ResultFormats)
+		} else {
+			pipeline.SendQueryPrepared(bi.sd.Name, c.eqb.ParamValues, c.eqb.ParamFormats, c.eqb.ResultFormats)
+		}
+	}
+
+	err := pipeline.Sync()
+	if err != nil {
+		return &pipelineBatchResults{ctx: ctx, conn: c, err: err, closed: true}
+	}
+
+	return &pipelineBatchResults{
+		ctx:      ctx,
+		conn:     c,
+		pipeline: pipeline,
+		b:        b,
+	}
+}
+
+func (c *Conn) sanitizeForSimpleQuery(sql string, args ...any) (string, error) {
+	if c.pgConn.ParameterStatus("standard_conforming_strings") != "on" {
+		return "", errors.New("simple protocol queries must be run with standard_conforming_strings=on")
+	}
+
+	if c.pgConn.ParameterStatus("client_encoding") != "UTF8" {
+		return "", errors.New("simple protocol queries must be run with client_encoding=UTF8")
+	}
+
+	var err error
+	valueArgs := make([]any, len(args))
+	for i, a := range args {
+		valueArgs[i], err = convertSimpleArgument(c.typeMap, a)
+		if err != nil {
+			return "", err
+		}
+	}
+
+	return sanitize.SanitizeSQL(sql, valueArgs...)
+}
+
+// LoadType inspects the database for typeName and produces a pgtype.Type suitable for registration. typeName must be
+// the name of a type where the underlying type(s) is already understood by pgx. It is for derived types. In particular,
+// typeName must be one of the following:
+//   - An array type name of a type that is already registered. e.g. "_foo" when "foo" is registered.
+//   - A composite type name where all field types are already registered.
+//   - A domain type name where the base type is already registered.
+//   - An enum type name.
+//   - A range type name where the element type is already registered.
+//   - A multirange type name where the element type is already registered.
+func (c *Conn) LoadType(ctx context.Context, typeName string) (*pgtype.Type, error) {
+	var oid uint32
+
+	err := c.QueryRow(ctx, "select $1::text::regtype::oid;", typeName).Scan(&oid)
+	if err != nil {
+		return nil, err
+	}
+
+	var typtype string
+	var typbasetype uint32
+
+	err = c.QueryRow(ctx, "select typtype::text, typbasetype from pg_type where oid=$1", oid).Scan(&typtype, &typbasetype)
+	if err != nil {
+		return nil, err
+	}
+
+	switch typtype {
+	case "b": // array
+		elementOID, err := c.getArrayElementOID(ctx, oid)
+		if err != nil {
+			return nil, err
+		}
+
+		dt, ok := c.TypeMap().TypeForOID(elementOID)
+		if !ok {
+			return nil, errors.New("array element OID not registered")
+		}
+
+		return &pgtype.Type{Name: typeName, OID: oid, Codec: &pgtype.ArrayCodec{ElementType: dt}}, nil
+	case "c": // composite
+		fields, err := c.getCompositeFields(ctx, oid)
+		if err != nil {
+			return nil, err
+		}
+
+		return &pgtype.Type{Name: typeName, OID: oid, Codec: &pgtype.CompositeCodec{Fields: fields}}, nil
+	case "d": // domain
+		dt, ok := c.TypeMap().TypeForOID(typbasetype)
+		if !ok {
+			return nil, errors.New("domain base type OID not registered")
+		}
+
+		return &pgtype.Type{Name: typeName, OID: oid, Codec: dt.Codec}, nil
+	case "e": // enum
+		return &pgtype.Type{Name: typeName, OID: oid, Codec: &pgtype.EnumCodec{}}, nil
+	case "r": // range
+		elementOID, err := c.getRangeElementOID(ctx, oid)
+		if err != nil {
+			return nil, err
+		}
+
+		dt, ok := c.TypeMap().TypeForOID(elementOID)
+		if !ok {
+			return nil, errors.New("range element OID not registered")
+		}
+
+		return &pgtype.Type{Name: typeName, OID: oid, Codec: &pgtype.RangeCodec{ElementType: dt}}, nil
+	case "m": // multirange
+		elementOID, err := c.getMultiRangeElementOID(ctx, oid)
+		if err != nil {
+			return nil, err
+		}
+
+		dt, ok := c.TypeMap().TypeForOID(elementOID)
+		if !ok {
+			return nil, errors.New("multirange element OID not registered")
+		}
+
+		return &pgtype.Type{Name: typeName, OID: oid, Codec: &pgtype.MultirangeCodec{ElementType: dt}}, nil
+	default:
+		return &pgtype.Type{}, errors.New("unknown typtype")
+	}
+}
+
+func (c *Conn) getArrayElementOID(ctx context.Context, oid uint32) (uint32, error) {
+	var typelem uint32
+
+	err := c.QueryRow(ctx, "select typelem from pg_type where oid=$1", oid).Scan(&typelem)
+	if err != nil {
+		return 0, err
+	}
+
+	return typelem, nil
+}
+
+func (c *Conn) getRangeElementOID(ctx context.Context, oid uint32) (uint32, error) {
+	var typelem uint32
+
+	err := c.QueryRow(ctx, "select rngsubtype from pg_range where rngtypid=$1", oid).Scan(&typelem)
+	if err != nil {
+		return 0, err
+	}
+
+	return typelem, nil
+}
+
+func (c *Conn) getMultiRangeElementOID(ctx context.Context, oid uint32) (uint32, error) {
+	var typelem uint32
+
+	err := c.QueryRow(ctx, "select rngtypid from pg_range where rngmultitypid=$1", oid).Scan(&typelem)
+	if err != nil {
+		return 0, err
+	}
+
+	return typelem, nil
+}
+
+func (c *Conn) getCompositeFields(ctx context.Context, oid uint32) ([]pgtype.CompositeCodecField, error) {
+	var typrelid uint32
+
+	err := c.QueryRow(ctx, "select typrelid from pg_type where oid=$1", oid).Scan(&typrelid)
+	if err != nil {
+		return nil, err
+	}
+
+	var fields []pgtype.CompositeCodecField
+	var fieldName string
+	var fieldOID uint32
+	rows, _ := c.Query(ctx, `select attname, atttypid
+from pg_attribute
+where attrelid=$1
+	and not attisdropped
+	and attnum > 0
+order by attnum`,
+		typrelid,
+	)
+	_, err = ForEachRow(rows, []any{&fieldName, &fieldOID}, func() error {
+		dt, ok := c.TypeMap().TypeForOID(fieldOID)
+		if !ok {
+			return fmt.Errorf("unknown composite type field OID: %v", fieldOID)
+		}
+		fields = append(fields, pgtype.CompositeCodecField{Name: fieldName, Type: dt})
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return fields, nil
+}
+
+func (c *Conn) deallocateInvalidatedCachedStatements(ctx context.Context) error {
+	if txStatus := c.pgConn.TxStatus(); txStatus != 'I' && txStatus != 'T' {
+		return nil
+	}
+
+	if c.descriptionCache != nil {
+		c.descriptionCache.RemoveInvalidated()
+	}
+
+	var invalidatedStatements []*pgconn.StatementDescription
+	if c.statementCache != nil {
+		invalidatedStatements = c.statementCache.GetInvalidated()
+	}
+
+	if len(invalidatedStatements) == 0 {
+		return nil
+	}
+
+	pipeline := c.pgConn.StartPipeline(ctx)
+	defer pipeline.Close()
+
+	for _, sd := range invalidatedStatements {
+		pipeline.SendDeallocate(sd.Name)
+	}
+
+	err := pipeline.Sync()
+	if err != nil {
+		return fmt.Errorf("failed to deallocate cached statement(s): %w", err)
+	}
+
+	err = pipeline.Close()
+	if err != nil {
+		return fmt.Errorf("failed to deallocate cached statement(s): %w", err)
+	}
+
+	c.statementCache.RemoveInvalidated()
+	for _, sd := range invalidatedStatements {
+		delete(c.preparedStatements, sd.Name)
+	}
+
+	return nil
+}