Hi,
Whats the difference between an Index Oraganized table, a Table with a Btree Index and one with a bitmap Index.
Under what circumstances should each be used ??
Thanks
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Hi,
Whats the difference between an Index Oraganized table, a Table with a Btree Index and one with a bitmap Index.
Under what circumstances should each be used ??
Thanks
Article on IOT's:
http://www.dbasupport.com/oracle/ora8/iot.shtml
From Oracle8i DBA Bible by Gennick -
B*Tree indexes:
Good choice for most uses as they
-maintain the sort order of the data, making it easy to look up range data
-multicolumn indexes: you can use the leading edge columns to resolve a query, even if that query doesn't reference all columns in the index
-they automatically stay balanced
-performance remains relatively constant
- can also specify reverse and unique
Bitmapped indexes:
-use them to index columns with that contain a relatively small number of distinct values
-they are compact, saving space
-were designed for query intensive databases, so not recommended for OLTP databases
-not good for range scans
-are available only in Enterprise Edition