SYNOPSIS
dblink_open(text cursorname, text sql [, bool fail_on_error]) returns text
dblink_open(text connname, text cursorname, text sql [, bool fail_on_error]) returns text
DESCRIPTION
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Note
The following description applies only to Postgres-XC
dblink module has not been tested with Postges-XC yet. Although there're no reason that dblink does not run in Postgres-XC, the development team leaves the test and the use of this module entirely to users.
This section is identical to the corresponding PostgreSQL reference manual.
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Note
The following description applies only to PostgreSQL
dblink_open() opens a cursor in a remote database. The cursor can subsequently be manipulated with dblink_fetch() and dblink_close().
ARGUMENTS
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Note
The following description applies only to Postgres-XC
dblink module has not been tested with Postges-XC yet. Although there're no reason that dblink does not run in Postgres-XC, the development team leaves the test and the use of this module entirely to users.
This section is identical to the corresponding PostgreSQL reference manual.
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Note
The following description applies only to PostgreSQL
conname
- Name of the connection to use; omit this parameter to use the unnamed connection.
cursorname
- The name to assign to this cursor.
sql
- The SELECT statement that you wish to execute in the remote database, for example select * from pg_class.
fail_on_error
- If true (the default when omitted) then an error thrown on the remote side of the connection causes an error to also be thrown locally. If false, the remote error is locally reported as a NOTICE, and the function's return value is set to ERROR.
RETURN VALUE
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Note
The following description applies only to Postgres-XC
dblink module has not been tested with Postges-XC yet. Although there're no reason that dblink does not run in Postgres-XC, the development team leaves the test and the use of this module entirely to users.
This section is identical to the corresponding PostgreSQL reference manual.
-
Note
The following description applies only to PostgreSQL
Returns status, either OK or ERROR.
NOTES
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Note
The following description applies only to Postgres-XC
dblink module has not been tested with Postges-XC yet. Although there're no reason that dblink does not run in Postgres-XC, the development team leaves the test and the use of this module entirely to users.
This section is identical to the corresponding PostgreSQL reference manual.
-
Note
The following description applies only to PostgreSQL
Since a cursor can only persist within a transaction, dblink_open starts an explicit transaction block (BEGIN) on the remote side, if the remote side was not already within a transaction. This transaction will be closed again when the matching dblink_close is executed. Note that if you use dblink_exec to change data between dblink_open and dblink_close, and then an error occurs or you use dblink_disconnect before dblink_close, your change will be lost because the transaction will be aborted.
EXAMPLES
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Note
The following description applies only to Postgres-XC
dblink module has not been tested with Postges-XC yet. Although there're no reason that dblink does not run in Postgres-XC, the development team leaves the test and the use of this module entirely to users.
This section is identical to the corresponding PostgreSQL reference manual.
-
Note
The following description applies only to PostgreSQL
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SELECT dblink_connect('dbname=postgres'); dblink_connect ---------------- OK (1 row) SELECT dblink_open('foo', 'select proname, prosrc from pg_proc'); dblink_open ------------- OK (1 row)