SQLStore: Create utility for bulk inserts (#57632)

* Add batchsize to dialects

* Some intermediary progress

* Reflection-based implementation

* Validate batch size

* Implement a few simple tests

* Fix linter error

* Add debug message when falling back to default batch size

pkg/services/sqlstore/migrator/dialect.go

@@ -26,6 +26,7 @@ type Dialect interface {
 	Default(col *Column) string
 	BooleanStr(bool) string
 	DateTimeFunc(string) string
+	BatchSize() int
 
 	OrderBy(order string) string
 

pkg/services/sqlstore/migrator/mysql_dialect.go

@@ -44,6 +44,10 @@ func (db *MySQLDialect) BooleanStr(value bool) string {
 	return "0"
 }
 
+func (db *MySQLDialect) BatchSize() int {
+	return 1000
+}
+
 func (db *MySQLDialect) SQLType(c *Column) string {
 	var res string
 	switch c.Type {

pkg/services/sqlstore/migrator/postgres_dialect.go

@@ -45,6 +45,10 @@ func (db *PostgresDialect) BooleanStr(value bool) string {
 	return strconv.FormatBool(value)
 }
 
+func (db *PostgresDialect) BatchSize() int {
+	return 1000
+}
+
 func (db *PostgresDialect) Default(col *Column) string {
 	if col.Type == DB_Bool {
 		if col.Default == "0" {

pkg/services/sqlstore/migrator/sqlite_dialect.go

@@ -40,6 +40,12 @@ func (db *SQLite3) BooleanStr(value bool) string {
 	return "0"
 }
 
+func (db *SQLite3) BatchSize() int {
+	// SQLite has a maximum parameter count per statement of 100.
+	// So, we use a small batch size to support write operations.
+	return 10
+}
+
 func (db *SQLite3) DateTimeFunc(value string) string {
 	return "datetime(" + value + ")"
 }