align struct fields to reduce memory usage (#3168)

Author: jycor

driver/conn.go

@@ -23,13 +23,13 @@ import (
 
 // Conn is a connection to a database.
 type Conn struct {
-	dsn      string
-	options  *Options
-	dbConn   *dbConn
 	session  sql.Session
 	contexts ContextBuilder
+	options  *Options
+	dbConn   *dbConn
 	indexes  *sql.IndexRegistry
 	views    *sql.ViewRegistry
+	dsn      string
 }
 
 // DSN returns the driver connection string.

driver/driver.go

@@ -82,12 +82,11 @@ type ProviderWithSessionBuilder interface {
 // A Driver exposes an engine as a stdlib SQL driver.
 type Driver struct {
 	provider Provider
-	options  *Options
 	sessions SessionBuilder
 	contexts ContextBuilder
-
-	mu  sync.Mutex
-	dbs map[string]*dbConn
+	options  *Options
+	dbs      map[string]*dbConn
+	mu       sync.Mutex
 }
 
 // New returns a driver using the specified provider.
@@ -223,9 +222,9 @@ func (c *dbConn) close() error {
 type Connector struct {
 	driver     *Driver
 	options    *Options
+	dbConn     *dbConn
 	serverName string
 	dsn        string
-	dbConn     *dbConn
 }
 
 // Driver returns the driver.

driver/rows.go

@@ -26,10 +26,10 @@ import (
 
 // Rows is an iterator over an executed query's results.
 type Rows struct {
+	rows    sql.RowIter
 	options *Options
 	ctx     *sql.Context
 	cols    sql.Schema
-	rows    sql.RowIter
 }
 
 // Columns returns the names of the columns. The number of

driver/stmt.go

@@ -117,5 +117,10 @@ func (s *Stmt) query(ctx context.Context, bindings map[string]sqlparser.Expr) (d
 		return nil, err
 	}
 
-	return &Rows{s.conn.options, qctx, cols, rows}, nil
+	return &Rows{
+		options: s.conn.options,
+		ctx:     qctx,
+		cols:    cols,
+		rows:    rows,
+	}, nil
 }

engine.go

@@ -53,16 +53,16 @@ func init() {
 type Config struct {
 	// VersionPostfix to display with the `VERSION()` UDF.
 	VersionPostfix string
+	// TemporaryUsers adds any users that should be included when the engine is created. By default, authentication is
+	// disabled, and including any users here will enable authentication. All users in this list will have full access.
+	// This field is only temporary, and will be removed as development on users and authentication continues.
+	TemporaryUsers []TemporaryUser
 	// IsReadOnly sets the engine to disallow modification queries.
 	IsReadOnly     bool
 	IsServerLocked bool
 	// IncludeRootAccount adds the root account (with no password) to the list of accounts, and also enables
 	// authentication.
 	IncludeRootAccount bool
-	// TemporaryUsers adds any users that should be included when the engine is created. By default, authentication is
-	// disabled, and including any users here will enable authentication. All users in this list will have full access.
-	// This field is only temporary, and will be removed as development on users and authentication continues.
-	TemporaryUsers []TemporaryUser
 }
 
 // TemporaryUser is a user that will be added to the engine. This is for temporary use while the remaining features
@@ -136,18 +136,18 @@ func (p *PreparedDataCache) UncacheStmt(sessId uint32, query string) {
 
 // Engine is a SQL engine.
 type Engine struct {
+	Parser            sql.Parser
+	ProcessList       sql.ProcessList
 	Analyzer          *analyzer.Analyzer
 	LS                *sql.LockSubsystem
-	ProcessList       sql.ProcessList
 	MemoryManager     *sql.MemoryManager
 	BackgroundThreads *sql.BackgroundThreads
-	ReadOnly          atomic.Bool
-	IsServerLocked    bool
 	PreparedDataCache *PreparedDataCache
 	mu                *sync.Mutex
-	Version           sql.AnalyzerVersion
 	EventScheduler    *eventscheduler.EventScheduler
-	Parser            sql.Parser
+	ReadOnly          atomic.Bool
+	IsServerLocked    bool
+	Version           sql.AnalyzerVersion
 }
 
 var _ sql.StatementRunner = (*Engine)(nil)

enginetest/queries/check_scripts.go

@@ -540,16 +540,36 @@ var ChecksOnUpdateScriptTests = []ScriptTest{
 		},
 		Assertions: []ScriptTestAssertion{
 			{
-				Query:    "UPDATE sales JOIN (SELECT year_built FROM sales) AS t ON sales.year_built = t.year_built SET sales.year_built = 1901;",
-				Expected: []sql.Row{{types.OkResult{1, 0, plan.UpdateInfo{1, 1, 0}}}},
+				Query: "UPDATE sales JOIN (SELECT year_built FROM sales) AS t ON sales.year_built = t.year_built SET sales.year_built = 1901;",
+				Expected: []sql.Row{
+					{
+						types.OkResult{
+							RowsAffected: 1,
+							Info: plan.UpdateInfo{
+								Matched: 1,
+								Updated: 1,
+							},
+						},
+					},
+				},
 			},
 			{
 				Query:    "select * from sales;",
 				Expected: []sql.Row{{1901}},
 			},
 			{
-				Query:    "UPDATE sales as s1 JOIN (SELECT year_built FROM sales) AS t SET S1.year_built = 1902;",
-				Expected: []sql.Row{{types.OkResult{1, 0, plan.UpdateInfo{1, 1, 0}}}},
+				Query: "UPDATE sales as s1 JOIN (SELECT year_built FROM sales) AS t SET S1.year_built = 1902;",
+				Expected: []sql.Row{
+					{
+						types.OkResult{
+							RowsAffected: 1,
+							Info: plan.UpdateInfo{
+								Matched: 1,
+								Updated: 1,
+							},
+						},
+					},
+				},
 			},
 			{
 				Query:    "select * from sales;",
@@ -599,8 +619,18 @@ var ChecksOnUpdateScriptTests = []ScriptTest{
 				Expected: []sql.Row{{"WA"}},
 			},
 			{
-				Query:    "UPDATE sales JOIN locations SET sales.year_built = 2000, locations.state = 'CA';",
-				Expected: []sql.Row{{types.OkResult{2, 0, plan.UpdateInfo{2, 2, 0}}}},
+				Query: "UPDATE sales JOIN locations SET sales.year_built = 2000, locations.state = 'CA';",
+				Expected: []sql.Row{
+					{
+						types.OkResult{
+							RowsAffected: 2,
+							Info: plan.UpdateInfo{
+								Matched: 2,
+								Updated: 2,
+							},
+						},
+					},
+				},
 			},
 			{
 				Query:    "select * from sales;",

eventscheduler/enabled_event.go

@@ -26,11 +26,11 @@ import (
 
 // enabledEvent is used for storing a list of events that are enabled in EventScheduler.
 type enabledEvent struct {
-	edb             sql.EventDatabase
-	event           sql.EventDefinition
 	nextExecutionAt time.Time
+	edb             sql.EventDatabase
 	username        string
 	address         string
+	event           sql.EventDefinition
 }
 
 var _ fmt.Stringer = (*enabledEvent)(nil)

eventscheduler/event_executor.go

@@ -30,15 +30,15 @@ import (
 // to update the enabled events list in the eventExecutor. It also handles updating the event
 // metadata in the database or dropping it from the database after its execution.
 type eventExecutor struct {
+	catalog             sql.Catalog
 	bThreads            *sql.BackgroundThreads
 	list                *enabledEventsList
 	runningEventsStatus *runningEventsStatus
 	ctxGetterFunc       func() (*sql.Context, error)
 	queryRunFunc        func(ctx *sql.Context, dbName, query, username, address string) error
-	stop                atomic.Bool
-	catalog             sql.Catalog
 	tokenTracker        *tokenTracker
 	period              int
+	stop                atomic.Bool
 }
 
 // newEventExecutor returns a new eventExecutor instance with an empty enabled events list.

eventscheduler/event_scheduler.go

@@ -50,9 +50,9 @@ var _ sql.EventScheduler = (*EventScheduler)(nil)
 
 // EventScheduler is responsible for SQL events execution.
 type EventScheduler struct {
-	status        SchedulerStatus
 	executor      *eventExecutor
 	ctxGetterFunc func() (*sql.Context, error)
+	status        SchedulerStatus
 }
 
 // InitEventScheduler is called at the start of the server. This function returns EventScheduler object

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/dolthub/go-icu-regex v0.0.0-20250820171420-f2b78f56ce9f
 	github.com/dolthub/jsonpath v0.0.2-0.20240227200619-19675ab05c71
 	github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81
-	github.com/dolthub/vitess v0.0.0-20250814204310-c749d213f235
+	github.com/dolthub/vitess v0.0.0-20250828002016-b8fc8e714bf8
 	github.com/go-sql-driver/mysql v1.7.2-0.20231213112541-0004702b931d
 	github.com/gocraft/dbr/v2 v2.7.2
 	github.com/google/uuid v1.3.0