Syntax options:
QUERY_ESTIMATES
NOQUERY_ESTIMATES
Specifies whether or not SQL returns the estimated number of
rows and estimated number of disk I/O operations in the SQLCA
structure. If you specify the default, which is the QUERY_
ESTIMATES qualifier, SQL returns the estimated number of rows
in the field SQLCA.SQLERRD[2] and the estimated number of disk
I/O operations in the field SQLCA.SQLERRD[3]. The value of
SQLCA.SQLERRD[2] and SQLCA.SQLERRD[3] is normally 0 after you
execute an OPEN statement for a table.
The following example shows interactive SQL output from a
statement that accesses the INTRO_PERSONNEL database. The
database was loaded using the sample program SQL$INTRO_LOAD_
EMPL_C.SQLMOD with the QUERY_ESTIMATES qualifier on the module
language command line. The SQLCA.SQLERRD[2] field shows that SQL
estimates 100 rows. The SQLCA.SQLERRD[3] field shows that SQL
estimates 16 disk I/O operations.
$ SQL$
SQL> ATTACH 'FILENAME intro_personnel';
SQL> DECLARE MY_CURSOR
cont> TABLE CURSOR FOR
cont> SELECT * FROM EMPLOYEES;
SQL> OPEN MY_CURSOR;
SQL> SHOW SQLCA;
SQLCA:
SQLCAID: SQLCA SQLCABC: 128
SQLCODE: 0
SQLERRD: [0]: 0
[1]: 0
[2]: 100
[3]: 16
[4]: 0
[5]: 0
SQLWARN0: SQLWARN1: SQLWARN2:
SQLWARN3: SQLWARN4: SQLWARN5:
SQLWARN6: SQLWARN7: