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