CODEWITHSUNDEEP
sqldblink
kreamik
kreamik

Reputation: 627

Which databases has databaselink like Oracle has?

About dblink :
What Are Database Links? A database link is a pointer that defines a one-way communication path from an Oracle Database server to another database server. The link pointer is actually defined as an entry in a data dictionary table. To access the link, you must be connected to the local database that contains the data dictionary entry.

A database link connection is one-way in the sense that a client connected to local database A can use a link stored in database A to access information in remote database B, but users connected to database B cannot use the same link to access data in database A. If local users on database B want to access data on database A, then they must define a link that is stored in the data dictionary of database B.

A database link connection allows local users to access data on a remote database. For this connection to occur, each database in the distributed system must have a unique global database name in the network domain. The global database name uniquely identifies a database server in a distributed system.

Anyone can give me/us any RDBMS or non RDBMS that use dblink? i just know that oracle has it, any others?

i need to join any tables from different physical server

Upvotes: 0

Views: 243

Answers (1)

Dai
Dai

Reputation: 155400

Anyone can give me/us any RDBMS or non RDBMS that use dblink? i just know that oracle has it, any others?

The general term is "external data support" or variations thereof. The main way to implement heterogenous queries is with ODBC, so if "external data" doesn't work then searching for "ODBC" may also work.

It's impossible to say if any non-RDBMS support external data - because that's very open-ended (e.g. Word, Excel, etc, even Adobe Photoshop, all support external data connections).

But within the realm of RDBMS it's straightforward to find relevant documentation using Google:

  • MS Access:
    • Linked Tables (for tables in other *.mdb/*.accdb files.
    • External Data (lets you use SQL Server, or any ODBC data-source as a linked-table)
  • SQL Server
    • Linked Server (allows cross-server + cross-database queries, it also supports arbitrary ODBC and OLE-DB data-sources)
  • MySQL
    • Federated Tables (only supports other MySQL servers - I don't think MySQL supports ODBC).
  • PostgreSQL
  • IBM DB/2
    • External Tables (limited to external text and fixed-length files). I can't find any documentation for any built-in or first-party support for directly querying external data-sources from within IBM DB/2 (e.g. using ODBC).

Don't forget that almost every system will also ship with some form of "integration services" component that can also accomplish this, even without support for built-in ODBC or external-data support (often this works by running a daemon or agent process that just imports and syncs an external data-source with a table in a local database).

Upvotes: 1

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