table scan meaning in English
表扫描
Examples
- Table scans always read and lock all the rows in the table
表扫描总是读取（并上锁）表中所有行。 - Cumulative count of range and table scans started on the index or heap
从索引或堆开始的范围和表扫描的累积计数。 - However , if no indexes are available , the query optimizer must use a table scan
但如果没有索引，则查询优化器必须扫描表。 - A table scan generates many disk i o operations and can be resource intensive
扫描表会有许多磁盘i / o操作，并占用大量资源。 - It will choose indexed access if it has lower cost than table scan
如果使用索引的开销比表扫描的开销低，优化器将选择索引访问。