Обсуждение: postgres oracle emulation question
Does anyone know if there is a way in Postgres to emulate Oracle, in other words make Postgres think it is an Oracle database? If so, do you have any idea what percentage of people are doing this, and how successful they are with this? Also, how is this done? Do you know of any good links that discuss this. My manager is thinking about replacing a couple of Oracle databases with Postgres, and would like to know the answer to this question.
Thanks in advance.
Randy
On Tue, 22 Mar 2005 17:51:06 -0800, Randy Samberg <Randy.Samberg@palmsource.com> wrote: > > Does anyone know if there is a way in Postgres to emulate Oracle, in other > words make Postgres think it is an Oracle database? If so, do you have any > idea what percentage of people are doing this, and how successful they are > with this? Also, how is this done? Do you know of any good links that > discuss this. My manager is thinking about replacing a couple of Oracle > databases with Postgres, and would like to know the answer to this question. You mean make postgres slow, bloated & buggy? -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ L. Friedman netllama@gmail.com LlamaLand http://netllama.linux-sxs.org
Randy Samberg wrote: > Does anyone know if there is a way in Postgres to emulate Oracle, in > other words make Postgres think it is an Oracle database? If so, do > you have any idea what percentage of people are doing this, and how > successful they are with this? Also, how is this done? Do you know > of any good links that discuss this. My manager is thinking about > replacing a couple of Oracle databases with Postgres, and would like > to know the answer to this question. > > Thanks in advance. > > Randy What are you trying to accomplish? The PostgreSQL documentation has a nice section on converting from Oracle, and the topic is discussed frequently here. How are you connecting to the Oracle DB? JDBC, ORI? How transparent do you want this to be? I'm in the middle of converting a massive data collection database (hundreds of gigabytes) from Oracle to PostgreSQL. The app is written using Java and the database accessed via JDBC. My goal is to have source code transparency. Taking a bit of work on the stored procedure conversion, but so far the source code is intact. If you are hoping you can just take a C/C++ app using the OCI driver and point it to a PostgreSQL database, that's not going to happen, as the communications protocols are totally different. -- Guy Rouillier
PostgreSQL and Oracle are both relational databases. PostgreSQL and Oracle both use a very similar and interesting lock strategy for dealing with sets called MVCC. PostgreSQL and Oracle can both be accessed in complete a completely generic way using ODBC, OLEDB, JDBC, or a .NET provider. PostgreSQL and Oracle can both be accessed by embedded SQL. PostgreSQL and Oracle both have low level APIs (OCI for Oracle and pqlib for PostgreSQL). PostgreSQL and Oracle can both be accessed via stored programs written in many different programming languages. There will be minor differences in the SQL language used to manipulate data. If the objective of your boss is to create a web server or some other data centric application, then PostgreSQL is certainlya viable alternative to Oracle. ________________________________________ From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Randy Samberg Sent: Tuesday, March 22, 2005 5:51 PM To: pgsql-general@postgresql.org Subject: [GENERAL] postgres oracle emulation question Does anyone know if there is a way in Postgres to emulate Oracle, in other words make Postgres think it is an Oracle database? If so, do you have any idea what percentage of people are doing this, and how successful they are with this? Also, how is this done? Do you know of any good links that discuss this. My manager is thinking about replacing a coupleof Oracle databases with Postgres, and would like to know the answer to this question. Thanks in advance. Randy
Lonni J Friedman wrote: >On Tue, 22 Mar 2005 17:51:06 -0800, Randy Samberg ><Randy.Samberg@palmsource.com> wrote: > > >> >>Does anyone know if there is a way in Postgres to emulate Oracle, in other >>words make Postgres think it is an Oracle database? If so, do you have any >>idea what percentage of people are doing this, and how successful they are >>with this? Also, how is this done? Do you know of any good links that >>discuss this. My manager is thinking about replacing a couple of Oracle >>databases with Postgres, and would like to know the answer to this question. >> >> > >You mean make postgres slow, bloated & buggy? > > I am going to assume that was a joke, but it is not helpful. There is no real way to "emulate" Oracle. The best you could do is to have some level of software proxy that would understand the Oracle protocol and then translate that to PostgreSQL but you are looking at a huge mess. You would have to consider all the queries and such. What I can tell you is that it doesn't take much to port Oracle to PostgreSQL. There are some major differences in feature set but those can usually be solved programmatically. Sincerely, Joshua D. Drake > > > -- Command Prompt, Inc., home of Mammoth PostgreSQL - S/ODBC and S/JDBC Postgresql support, programming shared hosting and dedicated hosting. +1-503-667-4564 - jd@commandprompt.com - http://www.commandprompt.com PostgreSQL Replicator -- production quality replication for PostgreSQL
Вложения
On Tue, 22 Mar 2005 20:38:13 -0800, Joshua D. Drake <jd@commandprompt.com> wrote: > Lonni J Friedman wrote: > > >On Tue, 22 Mar 2005 17:51:06 -0800, Randy Samberg > ><Randy.Samberg@palmsource.com> wrote: > > > > > >> > >>Does anyone know if there is a way in Postgres to emulate Oracle, in other > >>words make Postgres think it is an Oracle database? If so, do you have any > >>idea what percentage of people are doing this, and how successful they are > >>with this? Also, how is this done? Do you know of any good links that > >>discuss this. My manager is thinking about replacing a couple of Oracle > >>databases with Postgres, and would like to know the answer to this question. > >> > >> > > > >You mean make postgres slow, bloated & buggy? > > > > > I am going to assume that was a joke, but it is not helpful. No, it wasn't a joke. I'm forced to maintain Oracle databases every day, and I've yet to find any redeeming qualities, so it baffles me why anyone would want to emulate them. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ L. Friedman netllama@gmail.com LlamaLand http://netllama.linux-sxs.org
Thanks to everyone for your comments on postgres oracle emulation. It was very helpful. Randy -----Original Message----- From: Joshua D. Drake [mailto:jd@commandprompt.com] Sent: Tuesday, March 22, 2005 8:38 PM To: Lonni J Friedman Cc: Randy Samberg; pgsql-general@postgresql.org Subject: Re: [GENERAL] postgres oracle emulation question Lonni J Friedman wrote: >On Tue, 22 Mar 2005 17:51:06 -0800, Randy Samberg ><Randy.Samberg@palmsource.com> wrote: > > >> >>Does anyone know if there is a way in Postgres to emulate Oracle, in >>other words make Postgres think it is an Oracle database? If so, do >>you have any idea what percentage of people are doing this, and how successful they are >>with this? Also, how is this done? Do you know of any good links that >>discuss this. My manager is thinking about replacing a couple of >>Oracle databases with Postgres, and would like to know the answer to this question. >> >> > >You mean make postgres slow, bloated & buggy? > > I am going to assume that was a joke, but it is not helpful. There is no real way to "emulate" Oracle. The best you could do is to have some level of software proxy that would understand the Oracle protocol and then translate that to PostgreSQL but you are looking at a huge mess. You would have to consider all the queries and such. What I can tell you is that it doesn't take much to port Oracle to PostgreSQL. There are some major differences in feature set but those can usually be solved programmatically. Sincerely, Joshua D. Drake > > > -- Command Prompt, Inc., home of Mammoth PostgreSQL - S/ODBC and S/JDBC Postgresql support, programming shared hosting and dedicated hosting. +1-503-667-4564 - jd@commandprompt.com - http://www.commandprompt.com PostgreSQL Replicator -- production quality replication for PostgreSQL
-----Original Message----- From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Lonni J Friedman Sent: Wednesday, March 23, 2005 6:06 AM To: Joshua D. Drake Cc: Randy Samberg; pgsql-general@postgresql.org Subject: Re: [GENERAL] postgres oracle emulation question On Tue, 22 Mar 2005 20:38:13 -0800, Joshua D. Drake <jd@commandprompt.com> wrote: > Lonni J Friedman wrote: > > >On Tue, 22 Mar 2005 17:51:06 -0800, Randy Samberg > ><Randy.Samberg@palmsource.com> wrote: > > > > > >> > >>Does anyone know if there is a way in Postgres to emulate Oracle, in other > >>words make Postgres think it is an Oracle database? If so, do you have any > >>idea what percentage of people are doing this, and how successful they are > >>with this? Also, how is this done? Do you know of any good links that > >>discuss this. My manager is thinking about replacing a couple of Oracle > >>databases with Postgres, and would like to know the answer to this question. > >> > >> > > > >You mean make postgres slow, bloated & buggy? > > > > > I am going to assume that was a joke, but it is not helpful. No, it wasn't a joke. I'm forced to maintain Oracle databases every day, and I've yet to find any redeeming qualities, so it baffles me why anyone would want to emulate them. >> 1. Excellent stability 2. Excellent scalability 3. Superb toolset 4. After-market support products abound 5. Stable, debugged access tools like the ODBC/OLEDB/.NET drivers On the downside: 1. $$$!!! 2. Installation is bad, even for a simple client. 3. Reinstallation/upgrade is always a nightmare. 4. God help you if your Oracle home should ever get moved or you move to a different disk drive. 5. Multiple OCI DLLs are sure to bring lots of intriguing surprises. << On the whole, it's not terrible if you can afford it.
On Wed, 23 Mar 2005 12:30:29 -0800, Dann Corbit <DCorbit@connx.com> wrote: > 1. Excellent stability Not in my experience. > 2. Excellent scalability Well, its an 800lb gorilla, so it starts off with enough momentum. > 3. Superb toolset Used sqlplus lately? > 4. After-market support products abound I suppose, if you like spending money on that sort of thing. > 5. Stable, debugged access tools like the ODBC/OLEDB/.NET drivers > > On the downside: > 1. $$$!!! > 2. Installation is bad, even for a simple client. Actually the installation is one of the few things that isn't too painful. Sure it ain't as simple as postgres, but its miles easier than DB2. > 3. Reinstallation/upgrade is always a nightmare. > 4. God help you if your Oracle home should ever get moved or you move > to a different disk drive. > 5. Multiple OCI DLLs are sure to bring lots of intriguing surprises. No DLLs on my Linux or Solaris boxen, but i've had problems aplenty with oracle's hackjobs pretending to be shared objects. > On the whole, it's not terrible if you can afford it. For what they charge (and that's ignoring support fees) it should & could be a hell of a lot better. But this thread is a touch off topic around here. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ L. Friedman netllama@gmail.com LlamaLand http://netllama.linux-sxs.org