CREATE OR REPLACE TRIGGER AUDIT_TRIGGER_NAME  BEFORE  INSERT  ON AUDIT_TABLE_LOGS   
ENABLE
DECLARE 
V_COUNT NUMBER;

    BEGIN
    
    SELECT COUNT(*) INTO V_COUNT FROM AUDIT_TABLE_LOGS   ; 
    
     IF V_COUNT  >= 5000 THEN
     
         DELETE FROM AUDIT_TABLE_LOGS  WHERE ROWID <= 1 ;
          
     END IF;

  END;
/

SQL> create table t10000 as select * from emp where 1=2;

Table created.

SQL> CREATE OR REPLACE TRIGGER ti_t10000
  2    FOR INSERT ON t10000
  3      COMPOUND TRIGGER
  4    BEFORE EACH ROW IS
  5    BEGIN
  6     :new.empno:=s.nextval;
  7    END BEFORE EACH ROW;
  8    AFTER STATEMENT IS
  9    BEGIN
 10      delete t10000 where empno<
 11        (select min(empno) from (select empno from t10000 order by empno desc) where rownum<=10);
 12    END AFTER STATEMENT;
 13  END;
 14  /

Trigger created.

SQL> insert into t10000 select * from emp where deptno=10;

3 rows created.

SQL> select count(*) from t10000;

  COUNT(*)
----------
         3

SQL> insert into t10000 select * from emp;

14 rows created.

SQL> select * from emp;

     EMPNO ENAME      JOB              MGR HIREDATE        SAL       COMM     DEPTNO
---------- ---------- --------- ---------- -------- ---------- ---------- ----------
      7369 SMITH      CLERK           7902 17.12.80        800                    20
      7499 ALLEN      SALESMAN        7698 20.02.81       1600        300         30
      7521 WARD       SALESMAN        7698 22.02.81       1250        500         30
      7566 JONES      MANAGER         7839 02.04.81       2975                    20
      7654 MARTIN     SALESMAN        7698 28.09.81       1250       1400         30
      7698 BLAKE      MANAGER         7839 01.05.81       2850                    30
      7782 CLARK      MANAGER         7839 09.06.81       2450                    10
      7788 SCOTT      ANALYST         7566 09.12.82       3000                    20
      7839 KING       PRESIDENT            17.11.81       5000                    10
      7844 TURNER     SALESMAN        7698 08.09.81       1500                    30
      7876 ADAMS      CLERK           7788 12.01.83       1100                    20
      7900 JAMES      CLERK           7698 03.12.81        950                    30
      7902 FORD       ANALYST         7566 03.12.81       3000                    20
      7934 MILLER     CLERK           7782 23.01.82       1300                    10

14 rows selected.

SQL> select * from t10000;

     EMPNO ENAME      JOB              MGR HIREDATE        SAL       COMM     DEPTNO
---------- ---------- --------- ---------- -------- ---------- ---------- ----------
       188 MARTIN     SALESMAN        7698 28.09.81       1250       1400         30
       189 BLAKE      MANAGER         7839 01.05.81       2850                    30
       190 CLARK      MANAGER         7839 09.06.81       2450                    10
       191 SCOTT      ANALYST         7566 09.12.82       3000                    20
       192 KING       PRESIDENT            17.11.81       5000                    10
       193 TURNER     SALESMAN        7698 08.09.81       1500                    30
       194 ADAMS      CLERK           7788 12.01.83       1100                    20
       195 JAMES      CLERK           7698 03.12.81        950                    30
       196 FORD       ANALYST         7566 03.12.81       3000                    20
       197 MILLER     CLERK           7782 23.01.82       1300                    10

10 rows selected.

SQL>