Yes, APEX uses a lot of cursors and if you dive into APEX tuning docs, this is also explained in the Application Express (APEX) Performance Tuning and Scalability Factors (Doc ID 1418234.1):
“(…) APEX applications (and mod_plsql applications, for that matter) do not reuse session cursors. This is the nature of the architecture (…)”.
So the Oracle database will get a lot of open cursors to handle. Sometimes you will read it can be fixed by raising the APEX/ORDS listener “jdbc.MaxLimit”. It’s probably a bit low by default for production systems and it can be raised to 25 or 50 or something whatever your need is, but that will not fix the ORA-01000. Continue reading