From dgoulet@vicr.com Wed, 30 May 2001 14:33:10 -0700 From: dgoulet@vicr.com Date: Wed, 30 May 2001 14:33:10 -0700 Subject: Re:RE: Your views on Quest - Shareplex Message-ID: MIME-Version: 1.0 Content-Type: text/plain Jacques, Your last statement is one place where I will agree on the "superiority" of SharePlex to Oracle's replication. In my experiences under replication a transaction will take longer than it should since you have to complete that transaction on the remote system as well as the local. SharePlex, since it gets it's queue from the redo logs, would allow the local transaction to complete in a timely manner while batching the transactions to the remote as a separate entity. Dick Goulet ____________________Reply Separator____________________ Author: Jacques Kilchoer Date: 5/30/2001 10:06 AM > -----Original Message----- > From: MacGregor, Ian A. [mailto:ian@SLAC.Stanford.EDU] > > We are looking into the product as well, but have yet to even > toy with the product. There is a "no chained rows" > restriction. I'm not sure what that statement means. Shareplex will replicate a table that has chained rows. > Shareplex does not replicate transactions on > sys objects. A table dropped on one side will not be > dropped on the other. It apparently will replicate truncates > however. It's one thing to read the logs and to find the > time when a truncate caused writes to the data dictionary, > but quite another to reconstruct the statement. Statement from a developer of Shareplex: <> Let me relate my personal experience working with Shareplex (BEFORE I was an employee with Quest Software). At a previous company we were looking for a replication tool at a company that did payroll taxes. There were large batch loads (bank records) every night, but especially at the end of each quarter and at the end of the year. We wanted to ensure that the replication tool we chose would be fast enough to keep up with the large data loads. When we tested Oracle Replication and Quest Shareplex, we found that Shareplex was significantly faster. I personally argued against it initially for some of the reasons posters here have mentioned (e.g. it uses "unsupported" means to accomplish its goal) but eventually we implemented Shareplex and were satisfied with the result. There can be some manual effort involved in reconciliation of discrepancies but we found that effort to be minor. Another factor that influenced our decision is that we were intending to use Shareplex for Oracle in conjunction with Shareplex FS to replicate datafiles created on the HP-UX server. ------ Jacques R. Kilchoer (949) 754-8816 Quest Software, Inc. 8001 Irvine Center Drive Irvine, California 92618 U.S.A. http://www.quest.com RE: Your views on Quest - Shareplex

> -----Original Message-----
> From: MacGregor, Ian A. [mailto:ian@SLAC.Stanford.EDU]
>
> We are looking into the product as well, but have yet to even
> toy with the product.  There is a "no chained rows"
> restriction.

I'm not sure what that statement means. Shareplex will replicate a table that has chained rows.

> Shareplex does not replicate transactions on
> sys objects.  A table dropped  on one side will not be
> dropped on the other.  It apparently will replicate truncates
> however.  It's one thing to read the logs and to find the
> time when a truncate caused writes to the data dictionary,
> but quite another to reconstruct the statement.

Statement from a developer of Shareplex:
<<Interesting statement as this is how we replicate DML.  Providing functionality for DDL is not at all impossible for us.  It is just one of the things on the list of enhancements that we plan for SharePlex, the priority of which is dependent on the market.>>


Let me relate my personal experience working with Shareplex (BEFORE I was an employee with Quest Software). At a previous company we were looking for a replication tool at a company that did payroll taxes. There were large batch loads (bank records) every night, but especially at the end of each quarter and at the end of the year. We wanted to ensure that the replication tool we chose would be fast enough to keep up with the large data loads. When we tested Oracle Replication and Quest Shareplex, we found that Shareplex was significantly faster. I personally argued against it initially for some of the reasons posters here have mentioned (e.g. it uses "unsupported" means to accomplish its goal) but eventually we implemented Shareplex and were satisfied with the result. There can be some manual effort involved in reconciliation of discrepancies but we found that effort to be minor. Another factor that influenced our decision is that we were intending to use Shareplex for Oracle in conjunction with Shareplex FS to replicate datafiles created on the HP-UX server.

------
Jacques R. Kilchoer
(949) 754-8816
Quest Software, Inc.
8001 Irvine Center Drive
Irvine, California 92618
U.S.A.
http://www.quest.com

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