Re: Migrating from Informix to Postgre - Mailing list pgsql-general
From | Bruce Momjian |
---|---|
Subject | Re: Migrating from Informix to Postgre |
Date | |
Msg-id | 200210181844.g9IIikd09330@candle.pha.pa.us Whole thread Raw |
In response to | Re: Migrating from Informix to Postgre ("Dinesh Anchan" <dinesh@pinksheets.com>) |
List | pgsql-general |
Dinesh Anchan wrote: > Thank you for your response. > > I understand that it is not heterogenous. Is it open? > > Let's say, I am running a transaction in Informix and part of that > transaction has to update another database which is running on Postgre. Is > this possible? Informix claims that it supports heterogenous transactions > as long as other participating database servers are capable of doing so. > > We were thinking of replacing servers one at a time. No, we don't support anything like that. We do support crossdb/server query execution, but those queries are separate events, not rolled back if the transaction aborts. > > Thank you for your advice. > > D > > -----Original Message----- > From: Bruce Momjian [mailto:pgman@candle.pha.pa.us] > Sent: Friday, October 18, 2002 11:51 AM > To: Dinesh Anchan > Cc: pgsql-general@postgresql.org > Subject: Re: [GENERAL] Migrating from Informix to Postgre > > > Dinesh Anchan wrote: > > Hi Everyone, > > > > I am a first timer in this forum. > > > > We are currently using Informix and looking for a more economic database > > solution(combination of Linux and Opensource database). We currently have > 5 > > database servers; 1 running on Sun E450(4 cpu), 2 on Sun E420(4 cpu), 1 on > > Sun E250 and 1 on Netra T1, with database sizes 30 GB, 12 GB, 12GB, 15GB, > > 2GB respectively. Databases on E420s are replicated between them. There > > are at least 10 tables which hold more than 75 million records and > > fragmented accross different tablespaces. They have indexes and used > > extensively in DSS type and as well as OLTP type of queries. > > > > I went through lot of material in the discussion group but could not find > a > > straight forward answer for the following questions. I would greatly > > appreciate if someone can share your experience with Postgre. > > > > 1. How comfortably Postgre can support these databases( with respect to > > volume)? > > No problem. We have Oracle/Informix folks migrating all the time. > > > 2. How reliable and what kind of replication Postgre provides? Is it log > > based or transaction based? > > Only single-master replication available in /contrib/rserv and > /contrib/dbmirror. We are working on multi-master for a later release. > > We also don't have point-in-time recovery yet, but that will be in 7.4, > due out in about 6 months. > > > 3. Does it support table fragmentation accross multiple tablespaces? > > No. > > > 4. Does it support raw devices? > > No. We feel the performance improvement on raw devices is minimal. > > > 5. I have read that it is transactional. But is it heterogeneous? Can I > > update multiple databases in multiple database servers of different family > > (like informix, MySQL etc) in a single transaction? > > You can only update one database per session connection. We do have > schemas in 7,3, though. We are in 7.3 beta now. > > > 6. How is the performance? > > Very similary to Informix/Oracle; faster for some things, slower for > others. > > -- > Bruce Momjian | http://candle.pha.pa.us > pgman@candle.pha.pa.us | (610) 359-1001 > + If your life is a hard drive, | 13 Roberts Road > + Christ can be your backup. | Newtown Square, Pennsylvania 19073 > > -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073
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