Problem:
Too Many Concurrent Execution of the Same Request error when
inserting or updating a table.

"Statement failed, SQLCODE = -693 
Too many concurrent executions of the same request"

Solution:
IB V4.x

This is caused by recursive triggers. Here is an example of a recursive
trigger that will return the  error message.

CREATE TRIGGER TGET_CUST_ID2 for TABLE1 
BEFORE INSERT 
AS 
BEGIN
   insert into table1(cust_id) values (5); 
   /* this is a recursive trigger where the same insert trigger is called 
   by itself and is creating an infinite loop*/
END!!

Re-evaluate the trigger to ensure there is no recursion.  Here 
is an example to fix the above example to eliminate recursion.

CREATE TRIGGER TGET_CUST_ID for TABLE1 
BEFORE INSERT
AS
BEGIN
   new.cust_id = 5;
END!!