Home/ Questions/Q 975443
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-16T03:35:09+00:00

This is a fairly simple question, but it’s one I can’t find a firm

  • 0

This is a fairly simple question, but it’s one I can’t find a firm answer on.

I have a parent table in PostgreSQL, and then several child tables which have been defined. A trigger has been established, and the children tables only have data inserted if a field, say field x, meets a certain criteria.

When I query the parent table with a field based upon x, PostgreSQL knows to immediately go to the child table that is related to that particular value of x.

That all being said, I don’t need to specify a particular index on the column x do I? PostgreSQL already knows how to sort on it, and by adding an index to the parent x, PostgreSQL is therefore generating unique indexes on x for each of the new child tables.

Creating that index is a bit redundant, right?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Creating an index on the child table for x, if x only has one value (or a very, very small number of values) if probably a loss, yes. The planner would scan the whole table anyway.

    If x is a timestamp and you’re specifying a timeframe that may not be a whole partition, or if x is another range or set of values, an index would be a win most likely.

    Edit: When I say one value or range of values, I mean, per child table.

    • 0