config+sqldb: make native SQL query config options configurable

Here, we make the sql query option params (batch size and pagination
size) configurable. The defaults for SQLite vs Postgres are still the
same but will be changed in an upcoming commit.

sqldb/config.go

@@ -28,6 +28,7 @@ type SqliteConfig struct {
 	MaxConnections int           `long:"maxconnections" description:"The maximum number of open connections to the database. Set to zero for unlimited."`
 	PragmaOptions  []string      `long:"pragmaoptions" description:"A list of pragma options to set on a database connection. For example, 'auto_vacuum=incremental'. Note that the flag must be specified multiple times if multiple options are to be set."`
 	SkipMigrations bool          `long:"skipmigrations" description:"Skip applying migrations on startup."`
+	QueryConfig    `group:"query" namespace:"query"`
 }
 
 // PostgresConfig holds the postgres database configuration.
@@ -38,6 +39,7 @@ type PostgresConfig struct {
 	Timeout        time.Duration `long:"timeout" description:"Database connection timeout. Set to zero to disable."`
 	MaxConnections int           `long:"maxconnections" description:"The maximum number of open connections to the database. Set to zero for unlimited."`
 	SkipMigrations bool          `long:"skipmigrations" description:"Skip applying migrations on startup."`
+	QueryConfig    `group:"query" namespace:"query"`
 }
 
 func (p *PostgresConfig) Validate() error {