Method CountTableRows

driver/mysql/extractor.go:859–877

CountTableRows counts exact number of rows on the original table

(db sql.QueryAble, table *common.Table)

// CountTableRows counts exact number of rows on the original table
func (e *Extractor) CountTableRows(db sql.QueryAble, table *common.Table) (int64, error) {
	//e.logger.Debug("As instructed, I'm issuing a SELECT COUNT(*) on the table. This may take a while")

	var query string
	// It only requires select privilege on target table to select its information_schema item.
	query = fmt.Sprintf(`select table_rows from information_schema.tables where table_schema = ? and table_name = ?`)
	var rowsEstimate int64
	err := db.QueryRowContext(e.ctx, query, table.TableSchema, table.TableName).Scan(&rowsEstimate)
	if err != nil {
		e.logger.Error("error when getting estimated row number (using information_schema)", "err", err,
			"schema", table.TableSchema, "table", table.TableName)
		rowsEstimate = 0
	}
	atomic.AddInt64(&e.mysqlContext.RowsEstimate, rowsEstimate)

	e.mysqlContext.Stage = common.StageSearchingRowsForUpdate
	e.logger.Debug("Estimated number of rows", "schema", table.TableSchema, "table", table.TableName, "n", rowsEstimate)
	return rowsEstimate, nil
}

// Read the MySQL charset-related system variables.
func (e *Extractor) readMySqlCharsetSystemVariables() error {