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CDC (Change Data Capture) and unidirecional replication options

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Date: Tue, 06 Nov 2007 14:33:13 -0800
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I will need replicate some tables (in uni-direcional mode only, ie, from many sources to the only dest db) and refreshing data nightly) , sources being some medium-size tables (a few Gbs in size) in SQLServer 2000, Oracle 9ir2EE and Oracle 10gr2 EE databases (in diverse servers, some running Windows, some linux, but all of them network-accesible) to a 10gr2 EE destination db : regarding the Oracle source dbs, I tested replication with MVs with success, but I´m considering CDC too, but I have some doubts to be smashed from the real experiences from the members :

  1. some Oracle source dbs are in noarchive mode : in the "OracleŽ Database Data Warehousing Guide 10g Release 2" manual, chapter 16 - Change Data CaptureAsynchronous Distributed HotLog Mode , it says :

"In the asynchronous Distributed HotLog mode, change data is captured from the online redo log file on the source database"

So as I understand the noarchive mode in the source dbs are not a problem, right ? I question it because the entry in puts archivemode as a need , togheter with activated global_name parameter, as some metalink notes do, is it right or wrong ?

b. some LONGs and LONG RAWs are present, unfortunately, and can´t be changed right now, and all the docs says that LONGs are not supported in replication of any type : can I create a view "translating" the LONGs to LOBs and use the view as the data source ? If not, some small example of triggers doing it ? Or other option to replicat this things ?

c) speaking in triggers, if I switch to synchronous CDC (the made with triggers one), is possible to refresh only at certain times ? The quoted manual says that sync CDC is in immediate, commit-base only, BUT imho if it maintains a log table (and it does) , maybe could be possible another way of refreshing...

d) any gotchas, recommendations and alike for this scene ?


Chiappa Received on Tue Nov 06 2007 - 16:33:13 CST

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