Re: Your views on Quest - Shareplex
Marc, You didn't mention the Oracle version, but I wouldn't be surprised if it was O7 as the serial push using the two-phase commit process doesn't scale well at all. The completely new architecture (AQ, parallel propagation, min communication, etc...) in O8 makes replication quite scalable even at very high transaction rates. -- Anita --- Marc Perkowitz [EMAIL PROTECTED] wrote: Rao, I worked at MCI Teleconferencing for a few years and they were using SharePlex for a reporting database. Oracle replication was not fast enough to support their transaction rate and they also could not afford the overhead on the source database that occurs with Oracle replication. After a few startup issues, it worked well for them, and AFAIK, they are still using it. During their research, they also found that Amazon.com was using it for, I think, data warehousing -- not their transactional system. Interesting enough, I understand that Oracle has built an equivalent feature that was planned to be part of 9i. I haven't read enough on 9i to see if it made it in there or not. Perhaps someone else knows about this. Marc Perkowitz Senior Consultant TWJ Consulting, LLP 847-256-8866 x15 www.twjconsulting.com - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Tuesday, May 29, 2001 12:16 PM List, My company is considering Quest - Shareplex. We are considering to use this in our dataware house. Basically, this will pull all the transactions from OLTP database and populate staging area in the dataware house. Could you please give your experiences and the pros and cons of this Shareplex product. Thanks, Rao -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rao, Maheswara INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Marc Perkowitz INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). __ Do You Yahoo!? Get personalized email addresses from Yahoo! Mail - only $35 a year! http://personal.mail.yahoo.com/ -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: A. Bardeen INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: Your views on Quest - Shareplex
Title: RE: Your views on Quest - Shareplex -Original Message- From: MacGregor, Ian A. [mailto:[EMAIL PROTECTED]] 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
RE: Your views on Quest - Shareplex
I verified this today actually. I had a conference call with Quest regarding SharePlex, and asked specifically about the chained rows. They said there is a reorganization step on the target database, so chained rows are not a problem. Jim Jim Hawkins Lead SAPR/3 Oracle Database Administrator MEMC Electronic Materials, Inc. 600 Pearl Drive St. Louis, MO 633376 9636) 474-7832 [EMAIL PROTECTED] (work) [EMAIL PROTECTED] (home) -Original Message- From: MacGregor, Ian A. [mailto:[EMAIL PROTECTED]] 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 -- Jim Hawkins Lead SAPR/3 Oracle Database Administrator MEMC Electronic Materials, Inc. 600 Pearl Drive St. Louis, MO 633376 9636) 474-7832 [EMAIL PROTECTED] (work) [EMAIL PROTECTED] (home) -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jim Hawkins INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: Your views on Quest - Shareplex - Thank you all
Thank you all for giving your time to express your opinions. I would be consolidating all the opinions I received in the list and send a mail within the next two days. I hope, this consolidation would help for any future queries on this subject. Thanks, Rao [EMAIL PROTECTED] -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rao, Maheswara INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: Your views on Quest - Shareplex - Thank you all
Title: RE: Your views on Quest - Shareplex - Thank you all If anyone wants to learn more about SharePlex for Oracle by Quest Software, I will be hosting an interactive conference call next Wednesday. This technical presentation describes SharePlex and how it offers live, up-to-the-minute replicas of production databases. Join us to discover how SharePlex can: Improve performance on your OLTP server up to 80% Minimize planned and unplanned downtime Enhance your clustering topology Improve your mirrored environment This technical presentation also includes customer examples from many different industries. No need to pre-register! Just download the presentation and dial in. Please note that you will be anonymous to the other participants to the call, although the operator will initially take your name and phone number for our records. NEXT CONFERENCE CALL: June 6th at 11:00am PST TO PARTICIPATE CALL: 800.967.7150 (Domestic); 719.457.2712 (International) CALL LEADER: Nick Wagner POWERPOINT SLIDES REQUIRED: http://www.quest.com/shareplex/docs/shareplexconfcall.ppt For additional information visit our web page at: www.quest.com/shareplex I look forward to having you on the call! Thanks, Nick Wagner SharePlex Technical Product Manager -Original Message- From: Rao, Maheswara [mailto:[EMAIL PROTECTED]] Sent: Wednesday, May 30, 2001 2:56 PM To: Multiple recipients of list ORACLE-L Subject: RE: Your views on Quest - Shareplex - Thank you all Thank you all for giving your time to express your opinions. I would be consolidating all the opinions I received in the list and send a mail within the next two days. I hope, this consolidation would help for any future queries on this subject. Thanks, Rao [EMAIL PROTECTED] -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rao, Maheswara INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: Your views on Quest - Shareplex
Title: RE: Your views on Quest - Shareplex -Original Message- From: MacGregor, Ian A. [mailto:[EMAIL PROTECTED]] The person giving the presentation on Shareplex stated that there could be no chained rows when the sharepex file, apparently analogous to the log miner dictionary file is created. Someone has already addressed this issue but I'll throw in my two cents again. There was a misunderstanding somewhere. When you activate shareplex (set up the software for replication, specifying objects to replicate, initial sync point, etc...) it's perfectly OK for tables to have chained rows, but the activation may take longer in that case. Truncate is not DML it is DDL. I didn't say there was a problem extracting DML statements. Oracle's log miner utility will do that. I said that Shareplex, as per the person who gave the presentation, will replicate truncates and marvelled at this capability. I regret that the developer did not fully comprehend what you meant. I'm sure she would appreciate your compliment. She did want to make sure that it was understood that it would be possible to replicate DDL, but that feature isn't in high enough demand (yet) apparently. -- 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
You can ask the listserv, send this commmand to [EMAIL PROTECTED] WHO list Sends a list of all subscribers to the list specified. This list may be partially or completely blocked, depending on the configuration specified by the list administrator. Most subscriber lists are ONLY available to other list members, however. You will be told if the list is not public. By default, your address will be included in these results unless you have issued the SET list CONCEAL command to hide your address for privacy concerns. The STATUS command will indicate your profile settings. Synonyms: RECIPIENTS, REVIEW, SEND/LIST See Also: SET, STATUS where list = oracle-l On Tue, May 29, 2001 at 10:16:55AM -0800, [EMAIL PROTECTED] wrote: Rao, Somewhere on this list there is a fellow from Quest, I've seen his e-mail, but can't remember who it is. Therefore If I'm leading down a wrong path he can correct. Anyway, as I understand SharePlex it extracts the transactions from the archived redo logs to replicate those transactions in another DB. Pretty slick, but redo logs are an Oracle company secret and therefore subject to change by them at will with no forewarning to anyone. Where can that leave you, out in the cold with a corrupt staging area? Very possibly. I know of another product that is suppose to help you analyze performance problems, but it connects directly to the SGA bypassing the kernel. Problem, it works as long as you don't change the starting address of the SGA and/or start paging it out of memory. Also, I had a demo copy of a product that supposedly re-organized the internals of the database files, while Oracle was shut down. Problem: A VERY big warning that if the DB would not restart after they finished, sorry!! Conclusion, any product that attaches to Oracle or it's files by other than the normal methods will not make it through the door. Dick Goulet Reply Separator Author: Rao; Maheswara [EMAIL PROTECTED] Date: 5/29/2001 9:16 AM List, My company is considering Quest - Shareplex. We are considering to use this in our dataware house. Basically, this will pull all the transactions from OLTP database and populate staging area in the dataware house. Could you please give your experiences and the pros and cons of this Shareplex product. Thanks, Rao -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rao, Maheswara INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- === Ray Stell [EMAIL PROTECTED] (540) 231-4109 KE4TJC28^D -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Ray Stell INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Re: Your views on Quest - Shareplex
Rao, Contact QUEST and see if they are holding any SURVIVAL deminstrations in your area. They are very informative and will answer a lot of your questions. I would suggest that you also invite your damagement to help in making the decision. ROR mª¿ªm [EMAIL PROTECTED] 05/29/01 01:16PM List, My company is considering Quest - Shareplex. We are considering to use this in our dataware house. Basically, this will pull all the transactions from OLTP database and populate staging area in the dataware house. Could you please give your experiences and the pros and cons of this Shareplex product. Thanks, Rao -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rao, Maheswara INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Ron Rogers INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: Your views on Quest - Shareplex
Title: RE: Your views on Quest - Shareplex As of a year ago it was single threaded and didn't handle long columns. -Original Message- From: Rao, Maheswara [mailto:[EMAIL PROTECTED]] Sent: Tuesday, May 29, 2001 10:17 AM To: Multiple recipients of list ORACLE-L Subject: Your views on Quest - Shareplex List, My company is considering Quest - Shareplex. We are considering to use this in our dataware house. Basically, this will pull all the transactions from OLTP database and populate staging area in the dataware house. Could you please give your experiences and the pros and cons of this Shareplex product. Thanks, Rao -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rao, Maheswara INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Re: Your views on Quest - Shareplex
Rao, I worked at MCI Teleconferencing for a few years and they were using SharePlex for a reporting database. Oracle replication was not fast enough to support their transaction rate and they also could not afford the overhead on the source database that occurs with Oracle replication. After a few startup issues, it worked well for them, and AFAIK, they are still using it. During their research, they also found that Amazon.com was using it for, I think, data warehousing -- not their transactional system. Interesting enough, I understand that Oracle has built an equivalent feature that was planned to be part of 9i. I haven't read enough on 9i to see if it made it in there or not. Perhaps someone else knows about this. Marc Perkowitz Senior Consultant TWJ Consulting, LLP 847-256-8866 x15 www.twjconsulting.com - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Tuesday, May 29, 2001 12:16 PM List, My company is considering Quest - Shareplex. We are considering to use this in our dataware house. Basically, this will pull all the transactions from OLTP database and populate staging area in the dataware house. Could you please give your experiences and the pros and cons of this Shareplex product. Thanks, Rao -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rao, Maheswara INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Marc Perkowitz INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: Your views on Quest - Shareplex
Standby database? How do you recover a DB using archived redo logs? Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech International, Sussex, WI USA -Original Message- Sent: Tuesday, May 29, 2001 14:41 To: Multiple recipients of list ORACLE-L On Tuesday 29 May 2001 12:01, Jim Hawkins wrote: From note on MetaLink: 1) There is not sufficient information in the logs to logically replicate transactions, so the data applied to the destination system may be different from the primary, and therefore inaccurate. So how does a standby database work if the logs don't contain complete transactions? Jared -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jesse, Rich INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Re: Your views on Quest - Shareplex
I guess it is in the LOGICALLY. Standby databases are maintained as asynchronous physical copies - which is why they can at best be opened read-only. Typical technical doc obfuscation :-). Jim Hawkins wrote: Jared, That's a really good question! I don't know the answer... Sorry, Jim On Tuesday 29 May 2001 12:01, Jim Hawkins wrote: From note on MetaLink: 1) There is not sufficient information in the logs to logically replicate transactions, so the data applied to the destination system may be different from the primary, and therefore inaccurate. So how does a standby database work if the logs don't contain complete transactions? Jared -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jared Still INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Jim Hawkins Lead SAPR/3 Oracle Database Administrator MEMC Electronic Materials, Inc. 600 Pearl Drive St. Louis, MO 633376 9636) 474-7832 [EMAIL PROTECTED] (work) [EMAIL PROTECTED] (home) -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jim Hawkins INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Regards, Stephane Faroult Oriole Corporation Voice: +44 (0) 7050-696-269 Fax:+44 (0) 7050-696-449 Performance Tools Free Scripts -- http://www.oriole.com, designed by Oracle DBAs for Oracle DBAs -- -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Stephane Faroult INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: Your views on Quest - Shareplex
Title: RE: Your views on Quest - Shareplex -Original Message- From: Brian MacLean [mailto:[EMAIL PROTECTED]] As of a year ago it was single threaded and didn't handle long columns. I talked to one of the SharePlex developers. a) Shareplex has handled long columns for as long as she remembers (a little more than three years). b) Shareplex has recently supported LOB columns in a production release. c) The next version will include multi-threaded posting. Mr. Goulet, just out of curiosity (for feedback to the product managers), what was it in Eyal Aronoff's response that made you think you would not like to use Shareplex? -- 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
Just something. First of all, I have never seen Shareplex in operation so this is my gut feeling, chiefly based on how I would have coded it. Most of the arguments against Shareplex has been about their using undocumented features - which I admit may be a concern but wouldn't keep me awake at night. The main difference I see between log-based replication and traditional, trigger-based replication is that with trigger-based replication the log is part of the transaction - in other words, you only see committed changes. With the logs, the picture is different, because you may have uncommitted as well as committed changes in them - you are a bit closer to what people do. Either they wait for transactions to have committed before forwarding them - which I think unlikely because at the first massive update they can go BANG, if what happens to rollback segments from time to time is anything to go by, or, and that's how I would have done it, they forward changes as they come, forwarding commits and rollbacks as well. And in my view, the problem is not on the source, but on the target side. I presume that one, or in the best of case, a limited number of sessions are replaying the original changes; if you have many concurrent sessions on the source, you have a kind of funnelling. Because of Oracle read consistency, the original transactions, if they are working on the same data, may not see exactly the same thing at the same moment. Oracle locks take care of that, but if you multiplex everything I do not see how to keep a consistent picture at the other end, even when strictly respecting chronology. A secondary, and relatively minor compared to the first one, concern would be what happens if a replication process crashes (I know, it's not supposed to happen) and if this is not spotted immediately? I presume that ARCHIVELOG is mandatory, but anyway you must probably have tight operations. It must be perfect for some operations, but I would feel uncomfortable using it on the case-study OLTP database. My 2 cents. Stéphane Faroult Rao, Maheswara wrote: List, My company is considering Quest - Shareplex. We are considering to use this in our dataware house. Basically, this will pull all the transactions from OLTP database and populate staging area in the dataware house. Could you please give your experiences and the pros and cons of this Shareplex product. Thanks, Rao -- -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Oriole account INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: Your views on Quest - Shareplex
Title: RE: Your views on Quest - Shareplex Our productionruns on amulti-threaded app. And, it is the Single threaded nature of Shareplex with the LONG columns in the db that did not make it suitable for us. Shareplex just could not catch up with the DML activity in our Production. -Original Message-From: Jacques Kilchoer [mailto:[EMAIL PROTECTED]]Sent: Tuesday, May 29, 2001 4:20 PMTo: Multiple recipients of list ORACLE-LSubject: RE: Your views on Quest - Shareplex -Original Message- From: Brian MacLean [mailto:[EMAIL PROTECTED]] As of a year ago it was single threaded and didn't handle long columns. I talked to one of the SharePlex developers. a) Shareplex has handled long columns for as long as she remembers (a little more than three years). b) Shareplex has recently supported LOB columns in a production release. c) The next version will include multi-threaded posting. Mr. Goulet, just out of curiosity (for feedback to the product managers), what was it in Eyal Aronoff's response that made you think you would not like to use Shareplex? -- 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
We are looking into the product as well, but have yet to even toy with the product. There is a no chained rows restriction. 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. I didn't think Quest was pushing Shareplex for disaster recovery tool but for replication. Ian MacGregor Stanford Linear Accelertor Center [EMAIL PROTECTED] -Original Message- Sent: Tuesday, May 29, 2001 1:45 PM To: Multiple recipients of list ORACLE-L Here's a theory: Eyal is referring to chained and migrated rows. With media recovery, the recovering instance infers where the migrated or chained data is located, becuase it is an exact physical copy. Since the SharePlex replicated instance is not an exact physical copy of the primary, it must go back to the source database to figure out which blocks' changes represent changes for a block that SharePlex already knows about. -- Jeremiah Wilton http://www.speakeasy.net/~jwilton On Tue, 29 May 2001, Jared Still wrote: So how does a standby database work if the logs don't contain complete transactions? On Tuesday 29 May 2001 12:01, Jim Hawkins wrote: From note on MetaLink: 1) There is not sufficient information in the logs to logically replicate transactions, so the data applied to the destination system may be different from the primary, and therefore inaccurate. -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jeremiah Wilton INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: MacGregor, Ian A. INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
