Hi..
Taking the example you have mentioned,
"create index <index name> on <table name> (<column names>)
tablespace <table space name> parallel (degree 4) nologging
compress 5;"
1. <index name> is the name of the index being created.
2. <table name>( column name) is the list of column names of a table for
which index is being created.
3. <tablespace name> is the name of the tablespace where it would be
created. The index data would reside in the datafile for the tablespace.
4. parallel (degree 4) means the creation of the index would involve 4
parallel servers to act on it. This would reduce the overall time required
to create the index.
5. nologging means that redo is not generated for this operation.. thereby
making it faster.
6. COMPRESS means key compression, which eliminates repeated occurrence of
key column values and may substantially reduce storage. Use integer to
specify the prefix length (number of prefix columns to compress).
For unique indexes, the valid range of prefix length values is from 1 to the
number of key columns minus 1. The default prefix length is the number of
key columns minus 1.
For nonunique indexes, the valid range of prefix length values is from 1 to
the number of key columns. The default prefix length is the number of key
columns.
Hope this helps.
Thanx.
Trupti
-----Original Message-----
From: sandeep3
[mailto:oracledba-ezmlmshield-x56660406.[Email address protected]
Sent: Wednesday, November 30, 2005 10:28 AM
To: LazyDBA Discussion
Subject: meanings of different clauses in index creation statements
>
> Can some one explain the meaning of clauses parallel, nologging
> and
> compress
>
> create index <index name> on <table name> (<column names>)
> tablespace <table space name> parallel (degree 4) nologging
> compress 5;
>
> Sandeep Saxena
>
ForwardSourceID:NT000221EA
Notice: The information contained in this e-mail message and/or attachments
to it may contain confidential or privileged information. If you are not
the intended recipient, any dissemination, use, review, distribution,
printing or copying of the information contained in this e-mail message
and/or attachments to it are strictly prohibited. If you have received
this communication in error, please notify us by reply e-mail or telephone
and immediately and permanently delete the message and any attachments.
Thank you
--------
website: http://www.LazyDBA.com
Please don't reply to RTFM questions
Oracle documentation is here: http://tahiti.oracle.com
To unsubscribe: see http://www.lazydba.com/unsubscribe.html
To subscribe: see http://www.lazydba.com
By using this list you agree to these
terms:http://www.lazydba.com/legal.html
Oracle LazyDBA home page