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From:Kostas Karadamoglou Date:August 14 2005 2:42pm
Subject: Re: Design problem About application related with cached rows
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I thought this solution but it needs an extra software at the remote 
database. I would prefer to contact from the cache database directly to 
the remote database using SQL.

But even using those 3 steps there is a problem. The only interface that 
I have is JDBC/SQL. That means that the only solution would be to fetch 
all the rows in a resultset locally(remote database) and then in a for 
loop I must check all the IDs that I dont need with the ID of the 
current row within the loop.

I think this is a little bit time consuming!!

Do you know I more effective way to do this?

thank you in advance, Kostas

Pooly wrote:
> Hi,
> 
> Try in in two fold.
> 1. Get all the ID you have in your remote DB
> 2. check those localy with the ones you have in cache
> 3. Get all the info you need after you remove the ID you already have.
> 
> 2005/8/14, Kostas Karadamoglou <karadamoglou_k@stripped>:
> 
>>Hello,
>>
>>I try to create an application for my dissertation that caches rows from
>>an romote database. The application handles a cache database which is
>>identical with the original. The only difference is that it does not
>>have autogenerated fields and referential integrity is omitted.
>>
>>I have designed a caching algorithm specific to the context of my
>>applocation. However, I have a problem that I cannot solve it:
>>
>>I want to send a query to the remote database and then store the result
>>to the cache instance. The cache database might have rows that can be
>>duplicate with some rows of the resultset retrieved from the query.
>>
>>The easy solution is to insert all the rows of the resultset one by one
>>after I check their existence at the cache table. However, this solution
>>impose network latency to the network because useless data is moved on
>>the net.
>>
>>Do you know any efficient way to fetch the exception (the rows that dont
>>exist at the cache instance) of rows from the remote database using sql
>>queries?
>>
>>I tried to use the following kind of query but the database returns an
>>overflow message if the query string is too long.
>>
>>SELECT * FROM Customers WHERE CustomerID NOT IN (01,02, 03, ...);
>>
>>
>>--
>>MySQL General Mailing List
>>For list archives: http://lists.mysql.com/mysql
>>To unsubscribe:    http://lists.mysql.com/mysql?unsub=1
>>
>>
> 
> 
> 

Thread
Design problem About application related with cached rowsKostas Karadamoglou14 Aug
  • Re: Design problem About application related with cached rowsPooly14 Aug
    • Re: Design problem About application related with cached rowsKostas Karadamoglou14 Aug
      • Re: Design problem About application related with cached rowsPooly14 Aug