How can I create multiple databases in Oracle SE1 11.2 rds instance? - oracle

I have a Oracle SE1 11.2 instance running. It has one database in it. How can I create another database. I have been using Mysql so far and I am able to create as many databases with it but when tried with Oracle it gives an error.

Oracle is different from MySQL in how it terms databases, instances and schemas.
For Oracle each instance has only one database, but each database can have many schemas.
RDS provides only 1 instance(database), if you want many you pay for each instance you want by launching a new instance. However, each instance can support multiple schema's. On RDS you can create up to 30 schema's for Oracle. (see the RDS FAQ).
Because each user = a schema, and each schema has its own tables independent of other schema's you can have up to 30 "databases" by leveraging the schema model.

Related

Amazon RDS: How many Oracle instances/databases

I have a couple of questions on AWS RDS service for migrating an oracle 19c server on RHEL with 3 standalone instances and databases:
Can RDS instance support multiple oracle standalone instances/databases or only one instance?
If I have an existing RDS service running in AWS, can I migrate another on-premise oracle database to the RDS database as another oracle schema?
Have not tried it yet.
RDS for Oracle limits one instance to a single database. However you can have multiple schemas in one database.
An account can have up to 40 BYOL type Oracle RDS instances, or up to 10 instances where license is included. You can also increase these limits by contacting AWS support.
See here for more details.
Each RDS instance equals one database. However, you can set up multiple RDS instances, if you want to.
For migrations, please have a look at the Database Migration Service (DMS). Regarding your schema in particular, please check the Schema Conversion Tool which is a part of the DMS.
Sorry I can’t be more specific as the questions are rather vague themselves.

How to migrate(convert) database(or just tables) from PostgreSQL to Oracle using only Oracle tools?

Data was sent to our company with PostgreSQL, but we are prohibited to use the tools of PostgreSQL , permitted the use of only Oracle.
How to migrate data from PostgreSQL to Oracle without using a third party application(they are also prohibited)? You can only use the tools of Oracle.
I found this article https://support.oracle.com/knowledge/Oracle%20Database%20Products/2220826_1.html but we don't have Support Identifier
We have one .sql file. It weighs 8 Gigabytes.
It looks like you have so many impediments in your company. Regarding Oracle's SQL Developer Migration Workbench, unfortunately it does not support the migration of PostgreSQL databases. However, the following 3rd-party software tools are available and may assist in migration, but I am afraid you cannot use them as you said that those products are forbidden:
http://www.easyfrom.net/download/?gclid=CNPntY36vsQCFUoqjgodHnsA0w#.VRBHKGPVuRQ
http://www.sqlines.com/postgresql-to-oracle
Other options will only move the data from your Postgresql database to Oracle database, it means that you must have the DDLs of the tables before to run the import:
To move data only, you can generate a flat file of the the
PostgreSQL data and use Oracle SQL*Loader.
Another option to migrate data only is to use Oracle Database
Gateway for ODBC which requires an ODBC driver to connect to the
PostreSQL database, and copy each table over the network using
sqlplus "COPY" or "CREATE TABLE AS SELECT" commands via oracle
database link.
Also, Oracle has discussion forum for migrating non-oracle databases to Oracle.
http://www.oracle.com/technetwork/database/migration/third-party-093040.html
But, if you have only a sql file, you should look at it to see whether you have both DDLs ( create tables and indexes, etc ) and the data itself as insert statements. If so, you need to split it and treat the DDLs to convert the original data types to Oracle datatypes.

Oracle interfaces - Postgresql

I need to create interfaces between two different databases. I have an Oracle database and another Postgresql database.
The problem is that the schemas and structures of the databases are different.
I have performed migration / interface processes between two Postgresql databases before, but never with Oracle.
I think it is possible to do it with DBlink.
I need to keep both databases updated (bidirectional).
What do you suggest is a good alternative?

Can Someone explain the database concept difference between mysql an Oracle?

I have started working with mysql earlier, where different database meant completely different database, and I can create delete databases.
but when I started to working with oracle, the structure really confused me, the 'database' term means the same in Oracle as Mysql? If not whats the difference?
Thanks!
Oracle doc explain the difference (and migration tips):
2.2.5.1 Databases
When migrating MySQL databases to Oracle, SQL Developer maps each MySQL database to a tablespace in Oracle. Database objects, such as tables, indexes and views are stored in the respective tablespaces and are referenced from the Oracle schema for the user that owns them.

AWS DMS - incremental migration from Oracle to Redshift

I am new to AWS DMS service. Plans are to migrate on-prem Oracle to Redshift. Before going into production environment, currently trying out a test Oracle RDS in AWS which is a small subset of actual database as source. So far have been successful in the bulk load and incremental migration from RDS to Redshift.
When it comes to on-prem oracle , particularly for the incremental load
1) As per document : http://docs.aws.amazon.com/dms/latest/sbs/CHAP_On-PremOracle2Aurora.Steps.ConfigureOracle.html, the on-prem needs to be enabled with supplemental logging. Plans are to use the following two commands.
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (PRIMARY KEY) COLUMNS;
The production database has multiple logging locations. Is there any other log settings other than the above two that I should be looking into for DMS to pick up multiple log locations?
2) In the same link given, point 4 says 'Create or configure a database account to be used by AWS DMS.'
Where should I create this user? on-prem oracle or AWS?
How do I configure DMS to use this user?
You need to read this documentation:
https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Source.Oracle.html
For your second question; You need to create a user in the Oracle source database, the section 'Working with a Self-Managed Oracle Database as a Source for AWS DMS' tells you all of the grants you need to give.
For your first question, if you look at the SQL Server documentation;
https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Source.SQLServer.html
It specifies the limitation of; 'SQL Server backup to multiple disks isn't supported. If the backup is defined to write the database backup to multiple files over different disks, AWS DMS can't read the data and the AWS DMS task fails.'
I can't see a similar stipulation in the oracle documentation, first link, I would hazard a guess that DMS is able, in the case of oracle, to determine and cope with multiple logging locations from a configuration value inside the database.

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