Indices and sequences [message #58564] |
Wed, 17 September 2003 04:54 ![Go to next message Go to next message](/forum/theme/orafaq/images/down.png) |
Sally
Messages: 3 Registered: September 2002
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Junior Member |
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Is it possible for a sequence on a primary key to be altered (i.e. reset) when dropping/creating an index on that primary key? Are there any possible scenarios where this could happen?
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Re: Indices and sequences [message #58565 is a reply to message #58564] |
Wed, 17 September 2003 07:07 ![Go to previous message Go to previous message](/forum/theme/orafaq/images/up.png) |
Thiru
Messages: 1089 Registered: May 2002
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Senior Member |
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Sally,
I havent come across a situation yet where dropping/creating an index on the primary key affecting the sequence. Sequence is an independent database structure and is not confined to a specific key or a table and all it does is provide unique values .
Remember that sequence increments even when you dont use the values to insert into the primary or unique key(ie say when you rollback the transaction).
In case of Cached sequences,values may be lost when you do a 'alter system flush shared pool' or when there is a 'shutdown abort'. You could prevent this by altering the sequence to NOCACHE before flushing the shared pool.
HTH
Thiru
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