UNLINK_SCHEMA as opposition of LINK_SCHEMA, LINK_SCHEMA RFE and questions

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t603

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Apr 26, 2022, 2:19:28 AM4/26/22
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Hello, may I ask You few questions about LINK_SCHEMA function? 

1) Is LINK_SCHEMA on 10+ or 100+ tables and views far more faster that 10+ or 100+ times CREATE LINKED TABLE? In other words is there time improvement due connection establishment? Or does LINK_SCHEMA internally call of 10+ or 100+ CREATE LINKED TABLE and there is no performance improvement? 

2) When I do not need linked schema anymore, is there something like UNLINK_SCHEMA? 

3) How can achieve, that linked table via LINK_SCHEMA are linked in read only mode similar to CREATE LINKED TABLE ... readlonly? 

Thank You in advance for answer, Stepan 

Andreas Reichel

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Apr 26, 2022, 3:37:15 AM4/26/22
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Greetings.

On Mon, 2022-04-25 at 23:19 -0700, t603 wrote:
Hello, may I ask You few questions about LINK_SCHEMA function? 

1) Is LINK_SCHEMA on 10+ or 100+ tables and views far more faster that 10+ or 100+ times CREATE LINKED TABLE? In other words is there time improvement due connection establishment? Or does LINK_SCHEMA internally call of 10+ or 100+ CREATE LINKED TABLE and there is no performance improvement? 

I think, this will perform very similar, but may depend on the exact circumstances.
As far as I understand it, the "LINKED" command only provide a framework for querying via a different JDBC connection and fetching records. Its an ETL alike mechanism.

So LINKED SCHEMA would only provide the JDBC connection URL for accessing the schema's table -- same way as LINKED TABLE would do,.


2) When I do not need linked schema anymore, is there something like UNLINK_SCHEMA? 

Would not that be a simple DROP SCHEMA?

Best regards
Andreas
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