DB2 Index storage structure

DB2 Types of VIEWS DB2 INDEX

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Similarly like tables, there is another component that needs to be discussed is index.

INDEX is the link to access the data from the database very quickly.

This index will decide the rows storing place based on the index type so that the data can be easily accessed without any delay.

CREATE INDEX used to create the INDEX.

SYSADM or SYSCTRL authority is required to create the index.

INDEX is an ordered set of pointers to the rows of table data.

DB2 uses indexes to uniqueness and improve the performance.

An index is stored separately from the data in table.

Index’s are physically stored in its index space.

The hierarchy of Index can be drawn like below.

			Storage Group
			   |
			   |
			   \/
			Database
			   |
			   |
			   \/
			Index Space
			   |
			   |
			   \/
			Index

STORAGE GROUP:

Storage group is nothing but the collection of same type volumes.

In other words, A Storage group is nothing but a set of storage objects.

A Storage group can have data sets in which the tables and indexes actually stored.

The volumes must have the direct access.

One storage group can contain maximum 133 volumes in it.

Storage group concept explained in detail here .

DATABASE:

A Database is the physical object and it contains the memory area.

Database name is nothing but the logical name to database where the tables are going to store.

Database is a set of structures, and structure can contains tables, table spaces and indexes etc,.

DB2 can control the data by using Database.

Once the table created in the database, the table will be referred and can be accessed by the Database name.

Database concept explained in detail here .

INDEX SPACE:

It is like similar to the Table Space.

The Index space was not required to create it separately.

Whenever the indexes are created the index space for the same will be created automatically.

Index space is used store the indexes for the table space.

Index space can contain more than one index.

Index space is similar to table space but only contains indexes in it.

When index created, index space will be created automatically.

INDEX:

INDEX is the link to access the data from the database very quickly.

This index will decide the rows storing place based on the index type so that the data can be easily accessed without any delay.

CREATE INDEX used to create the INDEX.

SYSADM or SYSCTRL authority is required to create the index.

INDEX is an ordered set of pointers to the rows of table data.

DB2 uses indexes to uniqueness and improve the performance.

An index is stored separately from the data in table.

Index’s are physically stored in its index space.

CREATE INDEX is used to create the index.

Index concept explained in detail here .


DB2 Types of VIEWS DB2 INDEX

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