I have two databases that have tables with identical schema. I want to compare the two tables. I learned that cross DB queries need a Database Link.
I use SQL developer and here are the properties of the connection that works
Connection Name: MyConn
UserName:SomeUser
password:SomePassword
Connection Type: Basic
Role: default
Host Name: 12.12.12.12
port:2521
SID: xe
I tired this command to create Database link
CREATE DATABASE LINK MyDBLink
CONNECT TO SomeUser
IDENTIFIED BY "SomePassword"
USING '(DESCRIPTION=
(ADDRESS=(PROTOCOL=TCP)(HOST=12.12.12.12)(PORT=2521))
(CONNECT_DATA=(SID=xe)))';
The command creates a link but when I try to test the link, the connection does not work. The connection times out in 60s.
Am I missing something ?
The Database-Link is between the two databases and not "outgoing" from your local sqldeveloper/client.
So even if you can reach the remote database from your local client, the remote database-server where you created the link might (and in this case indeed does) not reach the target of the database link.
The database link itself is created no matter if the remote database is reachable, or the credentials are incorrect, etc.
If you have the possibility you should directly log on the database server of the database where you created the link and check the network connection to the database server you want to reach from there. Using telnet might help you.
The best solution is to look at the network or operating system and open a path between the two servers, and then the database link should work. If that's not possible, you can use your desktop PC as a proxy.
The official way to route around network issues is to use Oracle Connection Manager. But in my experience that program is a bit hard to configure.
Another option is to create a database on your desktop, and create two database links to each server. If this desktop database is only used for linking to others, then the free Express Edition should be good enough. If you go down this route, be careful of performance problems when involving 3 databases. You'll probably want to compare hashes instead of actual data, to avoid network problems.
Related
On my Infa server PC, in Informatica Administration I created a repository service giving Oracle Database information. Once in Informatica I connect to this repository and there I want to create a mapping importing a table from a remote sql server pc (on my home network domain) and then create a workflow to put the data into an oracle target table.
Using ODBC admin console I created and tested the connection and I am also able to telnet the linked sql server and port.
Within informatica I created a relational connection for sql server and when I run the workflow I get the error reason (14007) failed to create and inituiate OLE DB instance and datatabase driven error, failed to connect to database using user I use in SSMS for windows authentication and connection string(). I would like to know, first of of all, if I am doing something wrong, willing to connect me to a repository with oracle database information and then use a sql server table on remote pc. Do I have to create another repository for Sql server and there use sql server tables or I can mix them? secondly I would like to know how to create a relational connection object in informatica for my linked sql server so that it will be the same of relatonal connection created with ODBC admin consolle. Last but not least I would like to understand why gives an error out saying I left connection string empty, when I cannot see a place where I can put it by creating the relational connection object
I might not be able to solve the problem completely, but here's few remarks that might be helpful:
PowerCenter Repository database is where PowerCenter will store all the metadata about the processes you create. It may be Oracle - that's perfectly fine. And as it is not releated to your data sources or targets, you do not need to create another one for different sources/targets. One is enough for all ot them.
Using PowerCenter Workflow Manager create the appropriate connections to all the systems you need. Here you create the connections that indicate ODBC/other connections that will be used by Integration Service to actually connect to your data sources and targets, hence
Make sure the ODBC / other data sources are specified on Intergration Service. It is the IS that will run the process, connect to systems specified in the process with the defined connections.
When you build the mappings, you create them in a client app (Mapping Designer) and you can connect to DB engines to create source and target definitions. Mark, that in such case you use the connection (eg. ODBC data source) defined on the client. Once you will try to actually run the workflow with the given mapping, it is executed on IS (mentioned above) where appropriate connections need to be defined - and that's completely separate.
When editing a session in a workflow, for each source and target you need to pick a connection defined in Informatica Repository, created as described in point 2 above (or use a variable to indicate one - but that's another story)
So the error you mention seems to be related to connection created in Workflow Manager - it probably does not specify the connection string that should refer the data source defined on IS.
currently, we are using oracle 8i and we are working to decommisson it.
I need to find out which all other databases are connecting to our database using db link.
Please note, I am not looking for the connection from our database to others database. I already got that information using all_Db_links.
If you audit connections to the database or look at the listener log, that will tell you the machines that are connecting to the database and the application that is connecting (that information is coming from the client so it could be spoofed but I'm assuming no one is actively trying to hide information from you). That should allow you to determine which connections are coming via database links. That may not tell you which database on the particular server is connecting if there are multiple databases on the same server using the same Oracle Home. But it should narrow it down to a relatively small number of databases that you can manually check.
I connected the main database in the dev.exs and it works fine. But in my project I plan to use several databases. I know that in the file dev.exs can connect multiple databases but this option doesn’t suit me. Databases connections will be stored in the main project database. I want to know: how can I connect to different databases using the elixir code without using a file dev.exs?
You can start multiple instances of your Repo with different connection options.
Then, use the Repo.put_dynamic_repo/1 function to tell the Repo which of the databases should be used for queries in the current process. (The documentation for this function also tells you how to start more of the same repo).
There's also a discussion document that goes more in-depth about this topic: https://hexdocs.pm/ecto/replicas-and-dynamic-repositories.html
I am new to Oracle database in general, but I'm attempting to get Oracle's SQL Developer running on a workstation that has pre-configured System DSNs created for an OracleRDB database. I've confirmed the ODBC connections are working because I can use MS Access to connect and link to the tables. The "test" options within ODBC also succeed. Now I am trying to get a similar connection created using SQL Developer so I can see the column types and write queries in a more useful editor.
Here's what I have available when examining the ODBC connection properties:
Now I'm trying to create a duplicate connection in SQL Developer, but I'm at a loss for why things don't work. I first tried using the default SQL Developer installation, but couldn't get things working. Then I discovered there's an OracleRDB extension available, so I installed that, but I keep getting this error when attempting to use similar values:
As I stated, these ODBC connections were pre-configured on the workstation I'm using, so I don't know anything more than what is provided by the Oracle ODBC driver window.
Is there something obvious I'm not seeing or doing to replicate this connection in SQL Developer? Or perhaps something else I can do to debug this to learn more?
UPDATE
On the advice of one answer I'm trying to make the connection with JDBC, but having a hard time understanding what I'm doing wrong. Here's another screenshot with the connection parameters I have available, but with the server and database names changed:
With these values (the port came from my tnsnames.ora file), if I try to make a JDBC connection I keep getting the following error from SQL Developer:
One final attempt I did was to use the proper values in the Oracle RDB tab, and when I use them and click 'test' the Testing Connection dialog just spins and never seems to return:
So I apologize for the long post here, but I'm struggling because there's just something I am really not understanding about how this all works. I appreciate everyone who took the time to read this question.
Oracle SQL Developer is a Java Application. You'll need to get the JDBC Driver for RDB.
Once you have that, in the SQL Developer preferences, find the Third Party JDBC section, and then use that to add an entry and point to the JAR for what you just installed.
Step by step instructions here.
Working connection string for RDB Thin Driver:
RDB_DB_CONN_STR = "jdbc:rdbThin://node.myplace.com:1707/";
where node.myplace.com is the name of the OpenVMS node hosting the RDB Thin Driver, 1707 is the port number assigned to the RDB Thin Driver.
I'm taking DB prog. class and we are required to use Oracle+ Oracle sql dev. I so far I got 3 DB in oracle each with a connection from Oracle sql dev.
In windows services I only have one service called OracleDBConsole"MY1stDB name" there's no similiar services for the other DBs I created.
When I try to start this service I receive error as the picture
I can connect through the connections in Oracle sql dev. to the other DB I created except the 1st one
Does anybody have an idea on this issue
As one of affected people, I finally found solution:
If this appears, run lsnrctl start as an administrator to start the listener.
Most probably your listener.ova and tnsnames.ova are improperly set.
OK you installed 3 instances on same machine. There are two possibilities.
They are all set up to use default ports so when one is started no other can start due to port conflict. In that case you need to reconfigure ports following documentation
Second possibility is you already have different ports for your instances. In that case please check your connection definitions if they use proper ports. First will probably need default 1521 but others needs other ports. You may try 1522 as when during instalation 1521 was used it could took next free. But generally you should go to NETWORK/ADMIN/listener.ora edit file and check what port is used. Then properly define connection in client tool.
But as said in comments. Installing 3 instances make no sense unless you're trying to do some study with DBlinks simulations.
Mentioned service relates to oracle enterprise manager service.you have this because it configured for your database. but to troubleshoot it please check its logs in %ORACLE_HOME%**HOSTNAME_DBNAME**\sysman\log*. check there logs and send to investigate.
regards,
Mohsen
There is insufficient detail about the error to know what the problem is, however my guess is that subsequent instances are attempting to use the same resource as the already started instance, most likely the port.
Nevertheless, your problem can be solved by not creating multiple instances of Oracle, but rather creating multiple databases in the one Oracle instance.
It is a virtual certainty that your teacher did not intend you to start multiple instances of Oracle.