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11g Result Cache [message #443791]

Wed, 17 February 2010 05:59

orafacjublu
Messages: 95
Registered: May 2006
Location: KOLKATA

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can anyone explain what is the need for result cache when the query is in the cache normally

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Re: 11g Result Cache [message #443797 is a reply to message #443791]

Wed, 17 February 2010 06:29

JRowbottom
Messages: 5933
Registered: June 2006
Location: Sunny North Yorkshire, ho...

Senior Member

Does the fact that Oracle describe s differently - Result Cache, as opposed to Buffer Cache not lead you to the conclusion that they are in fact doing different things?

The Buffer Cache caches entire data blocks as they are read from the files.

The Result Cache caches the result sets for individual queries - so if your query returns values from several different tables, some of which are computed then these values will be cached.

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Re: 11g Result Cache [message #443800 is a reply to message #443791]

Wed, 17 February 2010 06:34

Michel Cadot
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Registered: March 2007
Location: Nanterre, France, http://...

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It is very simple.
data block/buffer cache -> cache of data blocks
result cache -> cache of (query/function) results

Regards
Michel

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Re: 11g Result Cache [message #443896 is a reply to message #443797]

Wed, 17 February 2010 23:28

orafacjublu
Messages: 95
Registered: May 2006
Location: KOLKATA

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Then we can use a materialized view , what extra advantage does a result cache do?

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Re: 11g Result Cache [message #443914 is a reply to message #443896]

Thu, 18 February 2010 00:26

Michel Cadot
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Result cache is dynamic materialized view.
You can't create a mview for each query, you can have result cache for many queries (the one you think it is important).
Also you can cache subqueries that can be used inside many queries.

In the end, you cannot cache function result without result cache.

Regards
Michel

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Re: 11g Result Cache [message #444165 is a reply to message #443914]

Fri, 19 February 2010 00:59

orafacjublu
Messages: 95
Registered: May 2006
Location: KOLKATA

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how do we configure result cache in client for faster access of query result

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Re: 11g Result Cache [message #444170 is a reply to message #444165]

Fri, 19 February 2010 01:11

Michel Cadot
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Registered: March 2007
Location: Nanterre, France, http://...

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Result cache (the one we are talking about here) is in server not in client.
So query result can be shared among multiple sessions.

It is set by these parameters (details in Reference manual):

result_cache_max_result       
result_cache_max_size         
result_cache_mode             
result_cache_remote_expiration

In 11gR2 there is a new client side result cache set by the following parameters:

client_result_cache_lag       
client_result_cache_size

Regards
Michel

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Re: 11g Result Cache [message #444177 is a reply to message #444170]

Fri, 19 February 2010 02:10

tahpush
Messages: 961
Registered: August 2006
Location: Stockholm/Sweden

Senior Member

Presentation on youtube, which give you some good pointers.

Oracle 11g Result Cache Introduction

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