I can't say about CGI-Programs or Oracle DB but here is some RAM usage report from my 3 programs with ZEOS-Components.
I checked ram usage of 3 applications. All 32Bit, Windows XP and Zeos 7.1.3a
1. App (GUI-App)
Compiled with Delphi 7, TWebbrowser, huge GUI + Variables
12MB database Firebird 2.5 (~50.000 datarows in 24 Tables)
RAM usage: ~30MB (most of them used by TWebbrowser)
2. App (GUI-App)
Compiled with Lazarus 1.3 + fpc 2.6.4, (with embedded Forms, Lazreport, multilanguage support)
85 KB Sqlite3 database (~560 datarows in 11 tables)
RAM usage: ~20MB
3. App (GUI-App)
Like 2.App but with Firebird 2.5 Database from first app.
RAM usage: ~18MB at start, ~22-25MB after opened tabbed forms with db-components.