Consider mirroring smart-large-object chunks

You can achieve higher availability and faster access if you mirror chunks that contain metadata pages.

An sbspace is a logical storage unit composed of one or more chunks that store smart large objects, which consist of CLOB (character large object) or BLOB (binary large object) data.

The first chunk of an sbspace contains a special set of pages, called metadata, which is used to locate smart large objects in the sbspace. Additional chunks that are added to the sbspace can also have metadata pages if you specify them on the onspaces command when you create the chunk.

Consider mirroring chunks that contain metadata pages for the following reasons:
  • Higher availability

    Without access to the metadata pages, users cannot access any smart large objects in the sbspace. If the first chunk of the sbspace contains all of the metadata pages and the disk that contains that chunk becomes unavailable, you cannot access a smart large object in the sbspace, even if it resides on a chunk on another disk. For high availability, mirror at least the first chunk of the sbspace and any other chunk that contains metadata pages.

  • Faster access

    By mirroring the chunk that contains the metadata pages, you can spread read activity across the disks that contain the primary chunk and mirror chunk.


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