In Query 11 presented in this section, note the following points related to cursor behavior:

<2>   The DataServer uses the cursor to compare schema information. It does not fetch any column values.

<3>   The DataServer uses the cursor to compare schema information. It does not fetch any column values. Note that because the ORDER_ table contains a date, the DataServer does not reuse this cursor to fetch column values.

<4>   The cursor is used to perform the join by the SQLDB. The join still requires a lookahead cursor.

<5>   Since the query requests the ORDER_ row with a SHARE-LOCK, the DataServer must refetch each ORDER_ row to get all the columns. If the ORDER_ table did not have a record identifier (PROGRESS_RECID in this case), this query would fail. If you must retrieve the ORDER_ row with a SHARE-LOCK, removing the field list eliminates the need to refetch the row.

FOR EACH customer FIELDS (name custnum postalcode) NO-LOCK,
  EACH order FIELDS (orderdate salesrep) OF customer SHARE-LOCK:
  DISPLAY customer.name customer.custnum customer.postalcode
    order.orderdate order.salesrep.
END.
 
 OCI call OCIStmtPrepare <2>     sqlcrc = 41633
     SELECT /*+ INDEX(T0 CUSTOMER##PROGRESS_RECID) */ * FROM 
      DOCTEST.CUSTOMER T0 WHERE PROGRESS_RECID = :rid
 OCI call OCIStmtExecute-DescribeOnly <2>
 OCI call omru   <2>
 OCI call OCIHandleAlloc <0>
 OCI call OCIStmtPrepare <3>     sqlcrc = 60664
     SELECT /*+ INDEX(T0 ORDER_##PROGRESS_RECID) */ * FROM 
      DOCTEST.ORDER_ T0 WHERE PROGRESS_RECID = :rid
 OCI call OCIStmtExecute-DescribeOnly <3>
 OCI call omru   <3>
 OCI call OCIHandleAlloc <0>
 OCI call OCIStmtPrepare <4>     sqlcrc = 51753
     SELECT T0.PROGRESS_RECID unique_id_0,T0.CUST_NUM,T0.NAME,
      T0.POSTAL_CODE,T1.PROGRESS_RECID unique_id_1,T1.ORDER_DATE,
      T1.SALES_REP FROM DOCTEST.CUSTOMER T0,DOCTEST.ORDER_ T1 WHERE 
      (T1.CUST_NUM = T0.CUST_NUM)
 OCI call OCIStmtExecute <4>
 OCI call OCIStmtFetch <4>
 OCI call OCIStmtFetch <4>
 OCI call OCIHandleAlloc <0>
 OCI call OCIStmtPrepare <5>     sqlcrc = 18715
     SELECT /*+ INDEX(T0 ORDER_##PROGRESS_RECID) */ ORDER_NUM,CUST_NUM
     ,TO_CHAR(ORDER_DATE,'YYYYMMDDHH24MISS'),TO_CHAR(SHIP_DATE,'YYYYMM
     DDHH24MISS'),TO_CHAR(PROMISE_DATE,'YYYYMMDDHH24MISS'),CARRIER,INS
     TRUCTIONS,PO,TERMS,SALES_REP,PROGRESS_RECID  FROM DOCTEST.ORDER_ 
     T0 WHERE PROGRESS_RECID = :rid
 OCI call omru   <5>
 OCI call OCIStmtExecute <5>
	< repeat for each row > 
 OCI call OCIStmtExecute <5>
 OCI call omru   <4>