according to pg, sublink means the subquery that doesn't occur in from clause, for example: select a from TB where c> (select max(d) from TB1); eg: 1. where ATTRIBUTE >,=, <,>=,<=,!= SUBLINK 2. where ATTRIBUTE in SUBLINK 3. where ATTRIBUTE exist SUBLINK
according to pg, sublink means the subquery that doesn't occur in from clause, for example: select a from TB where c> (select max(d) from TB1);
eg: