在空表中执行缓慢的查询.(删除大量插入后)

Slow query execution in an empty table. (after deleting a large amount of inserts)(在空表中执行缓慢的查询.(删除大量插入后))

问题描述

我在 oracle 数据库中有一个表，有 15 个字段.该表有 3500000 个插入.我都删了.

I have a table in an oracle database with 15 fields. This table had 3500000 inserts. I deleted them all.

delete
from table

之后，每当我执行选择语句
即使桌子是空的，我的响应也很慢(7 秒).我只在我搜索的情况下得到正常响应根据索引字段.

After that, whenever I execute a select statement
I get a very slow response (7 sec) even though the table is empty. I get a normal response only in the case that I search according to an indexed field.

为什么?

推荐答案

正如 Gritem 所说，你需要了解高水位线等

As Gritem says, you need to understand high water marks etc

如果您现在不想truncate表(因为已插入新数据)，请使用alter table xyz收缩空间记录在此处 10g

If you do not want to truncate the table now (because fresh data has been inserted), use alter table xyz shrink space documented here for 10g

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