what is sublinks in query planner?

Started by Sandeep Guptaabout 12 years ago3 messagesgeneral
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#1Sandeep Gupta
gupta.sandeep@gmail.com

Hi,

I looked for description of sublinks in the code as well as online but
failed to come with any information. Was wondering someone can provide a
line or two of what sublinks are suppose to do?

Thanks.
Sandeep

#2Tom Lane
tgl@sss.pgh.pa.us
In reply to: Sandeep Gupta (#1)
Re: what is sublinks in query planner?

Sandeep Gupta <gupta.sandeep@gmail.com> writes:

I looked for description of sublinks in the code as well as online but
failed to come with any information. Was wondering someone can provide a
line or two of what sublinks are suppose to do?

They're sub-SELECTs used in expression contexts (ie, not directly in a
FROM list). The comments for the SubLink and SubPlan node types in
primnodes.h may help you.

regards, tom lane

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#3Sandeep Gupta
gupta.sandeep@gmail.com
In reply to: Tom Lane (#2)
Re: what is sublinks in query planner?

Hi Tom,

Sure. Thanks for the info. This helps. I will look into primnodes.h as
well.

-Sandeep

On Fri, Mar 28, 2014 at 3:56 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:

Show quoted text

Sandeep Gupta <gupta.sandeep@gmail.com> writes:

I looked for description of sublinks in the code as well as online but
failed to come with any information. Was wondering someone can provide a
line or two of what sublinks are suppose to do?

They're sub-SELECTs used in expression contexts (ie, not directly in a
FROM list). The comments for the SubLink and SubPlan node types in
primnodes.h may help you.

regards, tom lane