We have a local db (Oracle) where we want to query a remote db (postgres), the data to be retreived is in JSONB format.
What is the best way for achieving this ?
The tool for accessing PostgreSQL from Oracle database is GoldenGate.
The 12.2 documentation does not even list the jsonb data type, so it is probably is not supported (I guess Oracle didn't check PostgreSQL's documentation since 9.2, when json was introduced).
But then Oracle doesn't have a special JSON data type anyway, it stores JSON as VARCHAR2 or CLOB, so you can easily use a view in PostgreSQL that casts the jsonb to text and use that.
Related
If I use any ANSI supported data types like INTEGER, NUMERIC, REAL etc., as a data type for a column, or a variable in PL/SQL, will it have an additional cost for the database?
What are the pros and cons for using the ANSI supported data types in Oracle database? (Database Version: 19c)
ANSI data-types are just aliases for Oracle data types and will be converted to the equivalent Oracle data type.
From the documentation:
ANSI, DB2, and SQL/DS Data Types
SQL statements that create tables and clusters can also use ANSI data types and data types from the IBM products SQL/DS and DB2. Oracle recognizes the ANSI or IBM data type name that differs from the Oracle Database data type name. It converts the data type to the equivalent Oracle data type, records the Oracle data type as the name of the column data type, and stores the column data in the Oracle data type based on the conversions shown in the tables that follow.
ANSI SQL Data Type
Oracle Data Type
NUMERIC[(p,s)]DECIMAL[(p,s)] (Note 1)
NUMBER(p,s)
INTEGERINTSMALLINT
NUMBER(38)
FLOAT (Note 2)DOUBLE PRECISION (Note 3)REAL (Note 4)
FLOAT(126)FLOAT(126)FLOAT(63)
What are the pros and cons for using the ANSI supported data types in Oracle database?
There are no performance benefits or penalties as the type will be converted to the equivalent Oracle type. The main benefit would be the portability of code between different RDBMS.
Hstore is a schema less key value store inside of PostgreSQL that allows us to store data like hashes directly inside of a column
More infor here
http://schneems.com/post/19298469372/you-got-nosql-in-my-postgres-using-hstore-in-rails
What is the equivalent of this in Oacle 11g
Oracle offer a "Big Data" NoSQL system, but not as part of the relational DBMS
http://www.oracle.com/us/products/database/nosql/overview/index.html
I m accessing remote database through DBLINK, but when trying to fire select query to fetch image stored in BLOB datatype it gives me following error:
ORA-22992: cannot use LOB locators selected from remote tables
Thanks in Advance.
You didn't provide the statement you are trying to execute, but I guess you are trying to do something which simply isn't possible in Oracle 10g.
The docs at http://docs.oracle.com/cd/B19306_01/server.102/b14200/sql_elements001.htm#sthref161 state:
Oracle Database has limited support for remote LOBs. Remote LOBs are
supported in three ways.
Create table as select or insert as select.
Functions on remote LOBs returning scalars. SQL and PL/SQL functions having a LOB parameter and returning a scalar datatype are
supported. Other SQL functions and DBMS_LOB APIs are not supported for
use with remote LOB columns.
Data Interface for remote LOBs. You can insert a character or binary buffer into a remote CLOB or BLOB, and select a remote CLOB or
BLOB into a character or binary buffer.
These are the only supported syntax involving LOBs in remote tables.
No other usage is supported.
See the link for extended examples.
To access data of type BLOB use the PIC datatype. Build your query like this:
*select(
**select PIC from AGENT_SIGNATURES_TB#DBLINK**
) as PIC
from dual*
At least that worked for me on an Oracle database.
I have a Data Flow from an Oracle table to an MSSQL table with one field of data type BIT. The Oracle table is using the characters Y and N at the moment (I'm unsure of the data type and have no way of checking), but the MSSQL table needs to be data type BIT. What type of cast can I use on the Oracle query so that the data is pulled smoothly over?
Use char(1) and then use a derived column transformation like this:
(DT_BOOL)(OracleField == "Y"?1:0)
Give this column a name like OracleFieldAsBool
and then use it instead of the original column in the rest of your data flow.
I am getting the following error:
Microsoft OLE DB Provider for Oracle: Data type is not supported.
Could somebody help me figure out this please...
Situation:
Recently migrated database from SQL Server 2005 to Oracle 11g. One of the table has some columns of the data type ntext in SQL Server, which were converted to NCLOB during migration to Oracle. Client is Classic ASP page (VBScript) accessing the Oracle Database through OLEDB connection.
When the execution reaches the query (Select query) that reads the column of type NCLOB it is throwing the Microsoft OLE DB Provider for Oracle: Data type is not supported error. When I take out that particular column then the query is running fine...
QUESTION: How to read NCLOB, CLOB data values from Classic ASP pages?
Plz let me know if you need more information.....
Thank You..
I know that Microsoft's ODBC Driver for Oracle didn't support any of the LOB types-- I would wager that its OLE DB Provider didn't either given the error. Can you upgrade to the Oracle OLE DB Provider?
As an aside, since you are migrating from SQL Server to Oracle, do you really need to use the NCLOB data type? Since Oracle allows the database character set to be Unicode, you normally don't need (and don't want) to use the NVARCHAR2 or NCLOB data types unless you're stuck supporting an old database that requires a non-Unicode character set. For data that is English or Western Eurpoean in nature, storing data in a CLOB has substantial benefits in terms of storage space since the CLOB would store the data in UTF-8 rather than UTF-16 in an NCLOB (assuming that you picked a Unicode character set for the database). Eliminating the NVARCHAR2 and NCLOB columns also tends to make it much easier for front-end tools to handle the data.