Deferred Segment Creation of Oracle 11g

Deferred Segment Creation of Oracle 11g

This article mainly introduces the Deferred Segment Creation feature introduced in Oracle 11g, as well as the issues that need attention when we use this feature.

1) Deferred Segment Creation

In Oracle, table space, segments, partitions, and blocks are four layers of the logical storage structure. A data table is generally composed of one or more Segment objects (partition tables) segments. That is to say, when a data table is created, Oracle will create a Data Segment object corresponding to it.

After a Segment is created, the Oracle space management mechanism allocates at least one extent as needed for initialization. The size of each extent needs to be configured according to different tablespaces. However, before the 11g period, when a data table is created, a space Segment is allocated. However, the Deferred Segment Creation feature is introduced in Oracle 11g.

First, create a data table justForTest to check whether the database assigns a segment to the table.

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