473,326 Members | 2,136 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,326 software developers and data experts.

Distributed database question

I'm looking for documentation pointers to learn what I need to put together
a distributed database system. I've read through "Oracle 9i Database
Administrator's Guide: Distributed Database Concepts" and Oracle Database
Concepts: Introduction to the Oracle Server: Distributed Databases
Overview", but I don't see how to do what I want.

I would like to set up a distributed database system with location
transparency and a shared schema (i.e. horizontal fragmentation). I'll
provide a little more context: I have three databases, running on separate
systems, all of which use the identical schema. So, each has entries in a
table "foo", which are unique. I'd like to provide a global access to this
data, so a client can effectively query the set of databases. So, asking
for all entries in the "foo" table would retrieve the contents of db1.foo,
db2.foo, and db3.foo. Ideally, when all is said and done, I'm planning to
wrap this in an enterprise java bean to provide an object interface.

Database links looked like the closest idea I could find, but they don't
deal well with the idea that my "foo" table has entries spread across the db
instances.

A pointer in the right direction would be greatly appreciated.

Jason
ja***@fc.hp.com
Jul 19 '05 #1
7 3959
"J Goldman" <ja***@fc.hp.com> wrote in message
news:3f********@usenet01.boi.hp.com...
I'm looking for documentation pointers to learn what I need to put together a distributed database system. I've read through "Oracle 9i Database
Administrator's Guide: Distributed Database Concepts" and Oracle Database
Concepts: Introduction to the Oracle Server: Distributed Databases
Overview", but I don't see how to do what I want.

I would like to set up a distributed database system with location
transparency and a shared schema (i.e. horizontal fragmentation). I'll
provide a little more context: I have three databases, running on separate systems, all of which use the identical schema. So, each has entries in a
table "foo", which are unique. I'd like to provide a global access to this data, so a client can effectively query the set of databases. So, asking
for all entries in the "foo" table would retrieve the contents of db1.foo,
db2.foo, and db3.foo. Ideally, when all is said and done, I'm planning to
wrap this in an enterprise java bean to provide an object interface.

Database links looked like the closest idea I could find, but they don't
deal well with the idea that my "foo" table has entries spread across the db instances.

A pointer in the right direction would be greatly appreciated.

Jason
ja***@fc.hp.com

Why do you want them spread over 3 machines? On one machine you might want
to partition the data into 3 tables and access the partition. You could use
database links and views, but it is going to be very inefficient.(the link
might have to retrieve the whole table and resolve the query on the database
you are attached to - ouch, dragging all that data over a link.) Whereas a
RAC might be better.
Jim
Jul 19 '05 #2
"J Goldman" <ja***@fc.hp.com> wrote in message news:<3f********@usenet01.boi.hp.com>...
A pointer in the right direction would be greatly appreciated.

Jason
ja***@fc.hp.com I would like to set up a distributed database system with location
transparency and a shared schema (i.e. horizontal fragmentation). I'll
provide a little more context: I have three databases, running on separate
systems, all of which use the identical schema. So, each has entries in a
table "foo", which are unique. I'd like to provide a global access to this
data, so a client can effectively query the set of databases. So, asking
for all entries in the "foo" table would retrieve the contents of db1.foo,
db2.foo, and db3.foo. Ideally, when all is said and done, I'm planning to
wrap this in an enterprise java bean to provide an object interface.

Your scenario has 'DISASTER AHEAD' inscribed all over it. You would be
better off by using a few 1000 of voting machines using punchcards.
Your approach would require to use UNIONs for everything, which means
the database will resort to full table scan and sorting for ALL sql
you sunmit.
Need I say more? Why do you want this? Are you up for a career move,
or do you like getting sacked by HP?

Sybrand Bakker
Senior Oracle DBA
Jul 19 '05 #3

"Jim Kennedy" <kennedy-down_with_spammers@no_spam.comcast.net> wrote in
message news:eb*******************@rwcrnsc52.ops.asp.att.n et...
"J Goldman" <ja***@fc.hp.com> wrote in message
news:3f********@usenet01.boi.hp.com...
I'm looking for documentation pointers to learn what I need to put together
a distributed database system. I've read through "Oracle 9i Database
Administrator's Guide: Distributed Database Concepts" and Oracle Database Concepts: Introduction to the Oracle Server: Distributed Databases
Overview", but I don't see how to do what I want.

I would like to set up a distributed database system with location
transparency and a shared schema (i.e. horizontal fragmentation). I'll
provide a little more context: I have three databases, running on

separate
systems, all of which use the identical schema. So, each has entries in a table "foo", which are unique. I'd like to provide a global access to

this
data, so a client can effectively query the set of databases. So, asking for all entries in the "foo" table would retrieve the contents of db1.foo, db2.foo, and db3.foo. Ideally, when all is said and done, I'm planning to wrap this in an enterprise java bean to provide an object interface.

Database links looked like the closest idea I could find, but they don't
deal well with the idea that my "foo" table has entries spread across

the db
instances.

A pointer in the right direction would be greatly appreciated.

Jason
ja***@fc.hp.com

Why do you want them spread over 3 machines? On one machine you might

want to partition the data into 3 tables and access the partition. You could use database links and views, but it is going to be very inefficient.(the link
might have to retrieve the whole table and resolve the query on the database you are attached to - ouch, dragging all that data over a link.) Whereas a RAC might be better.
Jim

Well, the first reason why they're spread over three machines is that I'm
adding
this to an existing product, where the databases have already been set up
like this.
This is designed such that each machine controls its own domain and one
machine
cannot access another's data. Aside from security, locality of data is also
relevant.
I'm just adding a global management view to collect all that data.

I'll have to read up on RAC to see if that addresses my needs. Thanks.

Regards,
Jason
ja***@fc.hp.com

Jul 19 '05 #4
Well, thanks for the vote of confidence. I appreciate your point that
this approach doesn't seem doomed to success. With that in mind,
can you offer any contructive suggestion on how I might provide
global access to this data? My other main thought has been to create
a set of entity EJBs local to each machine, along with a set of global
session beans. The global session beans would use something like a
dbhost parameter (where appropriate) to guide which db should be
read. Generic requests would query all of the DBs.

Jason
ja***@fc.hp.com
"Sybrand Bakker" <po*****@sybrandb.demon.nl> wrote in message
news:a2**************************@posting.google.c om...
"J Goldman" <ja***@fc.hp.com> wrote in message

news:<3f********@usenet01.boi.hp.com>...
A pointer in the right direction would be greatly appreciated.

Jason
ja***@fc.hp.com

I would like to set up a distributed database system with location
transparency and a shared schema (i.e. horizontal fragmentation). I'll
provide a little more context: I have three databases, running on separate systems, all of which use the identical schema. So, each has entries in a table "foo", which are unique. I'd like to provide a global access to this data, so a client can effectively query the set of databases. So, asking for all entries in the "foo" table would retrieve the contents of db1.foo, db2.foo, and db3.foo. Ideally, when all is said and done, I'm planning to wrap this in an enterprise java bean to provide an object interface.

Your scenario has 'DISASTER AHEAD' inscribed all over it. You would be
better off by using a few 1000 of voting machines using punchcards.
Your approach would require to use UNIONs for everything, which means
the database will resort to full table scan and sorting for ALL sql
you sunmit.
Need I say more? Why do you want this? Are you up for a career move,
or do you like getting sacked by HP?

Sybrand Bakker
Senior Oracle DBA

Jul 19 '05 #5

"Jim Kennedy" <kennedy-down_with_spammers@no_spam.comcast.net> wrote in
message news:eb*******************@rwcrnsc52.ops.asp.att.n et...
Why do you want them spread over 3 machines? On one machine you might

want to partition the data into 3 tables and access the partition. You could use database links and views, but it is going to be very inefficient.(the link
might have to retrieve the whole table and resolve the query on the database you are attached to - ouch, dragging all that data over a link.) Whereas a RAC might be better.
Jim

Well, I did a little bit of reading and I'm not convinced that a cluster
approach will
really address my problem. I'm leaning towards more of an EJB approach that
I
mentioned in another response. Thanks for the suggestions though.

Regards,
Jason
ja***@fc.hp.com
Jul 19 '05 #6
No, move all the data to 1 machine and have 3 schemas. Then you can create
a view that joins the 3 schemas(1 view for each table). The entity bean
approach is a Java programmer with a hammer that thinks everything is a
nail.]
Jim

--
Replace part of the email address: ke************************@attbi.com
with family. Remove the negative part, keep the minus sign. You can figure
it out.
"J Goldman" <ja***@fc.hp.com> wrote in message
news:3f********@usenet01.boi.hp.com...
Well, thanks for the vote of confidence. I appreciate your point that
this approach doesn't seem doomed to success. With that in mind,
can you offer any contructive suggestion on how I might provide
global access to this data? My other main thought has been to create
a set of entity EJBs local to each machine, along with a set of global
session beans. The global session beans would use something like a
dbhost parameter (where appropriate) to guide which db should be
read. Generic requests would query all of the DBs.

Jason
ja***@fc.hp.com
"Sybrand Bakker" <po*****@sybrandb.demon.nl> wrote in message
news:a2**************************@posting.google.c om...
"J Goldman" <ja***@fc.hp.com> wrote in message news:<3f********@usenet01.boi.hp.com>...
A pointer in the right direction would be greatly appreciated.

Jason
ja***@fc.hp.com

I would like to set up a distributed database system with location
transparency and a shared schema (i.e. horizontal fragmentation). I'll provide a little more context: I have three databases, running on separate systems, all of which use the identical schema. So, each has entries
in a table "foo", which are unique. I'd like to provide a global access to this data, so a client can effectively query the set of databases. So, asking for all entries in the "foo" table would retrieve the contents of db1.foo, db2.foo, and db3.foo. Ideally, when all is said and done, I'm
planning
to wrap this in an enterprise java bean to provide an object interface.

Your scenario has 'DISASTER AHEAD' inscribed all over it. You would be
better off by using a few 1000 of voting machines using punchcards.
Your approach would require to use UNIONs for everything, which means
the database will resort to full table scan and sorting for ALL sql
you sunmit.
Need I say more? Why do you want this? Are you up for a career move,
or do you like getting sacked by HP?

Sybrand Bakker
Senior Oracle DBA


Jul 19 '05 #7
"Jim Kennedy" <kennedy-down_with_spammers@no_spam.comcast.net> wrote in message news:<mVsab.507793$Ho3.85596@sccrnsc03>...
No, move all the data to 1 machine and have 3 schemas. Then you can create
a view that joins the 3 schemas(1 view for each table). The entity bean
approach is a Java programmer with a hammer that thinks everything is a
nail.]
Jim

--
Replace part of the email address: ke************************@attbi.com
with family. Remove the negative part, keep the minus sign. You can figure
it out.
"J Goldman" <ja***@fc.hp.com> wrote in message
news:3f********@usenet01.boi.hp.com...
Well, thanks for the vote of confidence. I appreciate your point that
this approach doesn't seem doomed to success. With that in mind,
can you offer any contructive suggestion on how I might provide
global access to this data? My other main thought has been to create
a set of entity EJBs local to each machine, along with a set of global
session beans. The global session beans would use something like a
dbhost parameter (where appropriate) to guide which db should be
read. Generic requests would query all of the DBs.

Jason
ja***@fc.hp.com
"Sybrand Bakker" <po*****@sybrandb.demon.nl> wrote in message
news:a2**************************@posting.google.c om...
"J Goldman" <ja***@fc.hp.com> wrote in message news:<3f********@usenet01.boi.hp.com>... > A pointer in the right direction would be greatly appreciated.
>
> Jason
> ja***@fc.hp.com I would like to set up a distributed database system with location
> transparency and a shared schema (i.e. horizontal fragmentation). I'll > provide a little more context: I have three databases, running on separate > systems, all of which use the identical schema. So, each has entries in
a > table "foo", which are unique. I'd like to provide a global access to this > data, so a client can effectively query the set of databases. So, asking > for all entries in the "foo" table would retrieve the contents of db1.foo, > db2.foo, and db3.foo. Ideally, when all is said and done, I'm planning
to > wrap this in an enterprise java bean to provide an object interface.
>
Your scenario has 'DISASTER AHEAD' inscribed all over it. You would be
better off by using a few 1000 of voting machines using punchcards.
Your approach would require to use UNIONs for everything, which means
the database will resort to full table scan and sorting for ALL sql
you sunmit.
Need I say more? Why do you want this? Are you up for a career move,
or do you like getting sacked by HP?

Sybrand Bakker
Senior Oracle DBA


If the DBS have to be in different locations, dosn't sound like RAC
would do you much good. What about doing all the work in the Middle
Tier and have your java app connect to all three servers and launch a
seperate query to each one? The oracle app server 9iAS should be able
to deal with all this easily (have to spend money though if you don't
have it) as it's meant to connect to many nodes. I would be leary of
links and union which may come to a screaching hault if one of the DBs
is unavailable.

Not sure how much data you have or how often it gets inserts and
updates, or how up the the minute data your query requires, but look
into materialized views if data and activity set is not too large or
you could use replication to have at least one database with all 3 DBs
data (kind of a data mart approach).
Jul 19 '05 #8

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

1
by: channa_s | last post by:
Hi, I would be very grateful if anyone could help me with the following. I want to create a SIMPLE distributed database. It is as follows: There is a institution which has branches all...
7
by: Richard Maher | last post by:
Hi, I am seeking the help of volunteers to test some software that I've developed which facilitates distributed two-phase commit transactions, encompassing any resource manager (e.g. SQL/Server...
0
by: DotNetJunkies User | last post by:
I am writing a distributed transaction code. My current scenario include a client database(Suppose client- having 4 main database) which can be installed anywhere which would connect to a public...
1
by: Avanish Pandey | last post by:
Hello All We have 3 differen services (in 3 different server) Service A,B,C . We want to implement distributed transaction when call methods of B and C from A. Is it possible? if yes then how? ...
3
by: Joris Dobbelsteen | last post by:
Dear, I have some considerations I need to take designing a distributed application (it's for a school project). Basically I'm looking for some reference or guidiance material/literature and...
2
by: thunder | last post by:
Hey! Suggest me. What are needed to creat a distributed database library. Protocol,design,and implementation,etc... I am a master thesis student.
0
by: gshawn3 | last post by:
Hi, I am having a hard time creating a Trigger to update an Oracle database. I am using a SQL Server 2005 Express database on a Win XP Pro SP2 desktop, linked to an Oracle 10g database on a...
4
by: dgleeson3 | last post by:
Hello all I am creating a VB.Net distributed SQL server 2005 application. Each computer in the system has a database with a table of users and their telephone numbers. Each computer has a...
7
by: J Goldman | last post by:
I'm looking for documentation pointers to learn what I need to put together a distributed database system. I've read through "Oracle 9i Database Administrator's Guide: Distributed Database...
0
by: ryjfgjl | last post by:
ExcelToDatabase: batch import excel into database automatically...
0
isladogs
by: isladogs | last post by:
The next Access Europe meeting will be on Wednesday 6 Mar 2024 starting at 18:00 UK time (6PM UTC) and finishing at about 19:15 (7.15PM). In this month's session, we are pleased to welcome back...
1
isladogs
by: isladogs | last post by:
The next Access Europe meeting will be on Wednesday 6 Mar 2024 starting at 18:00 UK time (6PM UTC) and finishing at about 19:15 (7.15PM). In this month's session, we are pleased to welcome back...
0
by: jfyes | last post by:
As a hardware engineer, after seeing that CEIWEI recently released a new tool for Modbus RTU Over TCP/UDP filtering and monitoring, I actively went to its official website to take a look. It turned...
0
by: ArrayDB | last post by:
The error message I've encountered is; ERROR:root:Error generating model response: exception: access violation writing 0x0000000000005140, which seems to be indicative of an access violation...
1
by: PapaRatzi | last post by:
Hello, I am teaching myself MS Access forms design and Visual Basic. I've created a table to capture a list of Top 30 singles and forms to capture new entries. The final step is a form (unbound)...
1
by: Shællîpôpï 09 | last post by:
If u are using a keypad phone, how do u turn on JavaScript, to access features like WhatsApp, Facebook, Instagram....
0
by: af34tf | last post by:
Hi Guys, I have a domain whose name is BytesLimited.com, and I want to sell it. Does anyone know about platforms that allow me to list my domain in auction for free. Thank you
0
by: Faith0G | last post by:
I am starting a new it consulting business and it's been a while since I setup a new website. Is wordpress still the best web based software for hosting a 5 page website? The webpages will be...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.