关键字缓冲区保存了myisam表的索引块。

The key buffer stores index blocks for MyISAM tables.

youdao

这个例程将遍历tcp控制块表，并且对每个连接的超时(以计时单元为单位进行指定)进行递减操作，即每次减一。

This routine walks through the table of TCP control blocks and, for each connection, it decrements the timeout, specified in ticks, by one.

youdao

当扫描一个mdc表时，对于索引扫描，块锁可以推迟。

When scanning an MDC table, block locking could be deferred for an index scan.

youdao