Building a DB with performance in mind

Greetings everyone,

I am about to migrate to Postgres from MySQL. My DB isn't enormous (<
1gb), consists mostly of just text, but is accessed quite heavily.
Because size isn't a huge issue, but performance is, I am willing to
normalize as necessary.

Currently I have a table "Entries" containing 500k rows. The table
contains many text columns, and a few others:
EntryID (unique, indexed)
UserID (references "Users" table, indexed)
Private (boolean. indexed)

Most of my queries return rows based on UserID, and also only if
Private is FALSE. Would it be in the interest of best performance to
split this table into two tables: "EntriesPrivate",
"EntriesNotPrivate" and remove the "Private" column?

I appreciate any feedback. I'm certainly not a DB design expert. :)

Thanks,
Alex