Big overhead calling stored procedure vs query in oci program

Question

My previous question hasn;t got a reply. I guess I did not state it well so I rephrased it a little and repost here. Hopefully somebody can help me with this problem.
I'm a newbie on OCI. I hope to use OCI for array DML to improve performance. It takes only 1 seconds to insert 20,000 records using the simple insert query, which is almost a miracle to me.
Then I tested using a stored procedure. This SP does exactly the same thing as the query: Inserting into the table with the 10 parameter provided.
However, it takes 23 seconds for 20,000 records.
Is calling a stored procedure fundamentally slower than a query in Oci, or I just did it wrong?
Following is the codes:
sword Tform_1::update_all_rows(OCIEnv envhp, OCISvcCtx svchp, OCIError errhp, OCIStmt update_p, OCIStmt *select_p)
int *intArry = new int[20000];
for (int i = 0; i < 20000; i++)
intArry = 50000 + i;
// text mySql = (text ) "Insert into testPro (a, b, c, d, e, f, g, h, i, j) VALUES (:a, :b, :c, :d, :e, :f, :g, :h, :i, :j)";
text mySql = (text ) "BEGIN\
CDSDEVELOPER_UTILPKG.INSERTTESTPRO(:a, :b, :c, :d, :e, :f, :g, :h, :i, :j);\END;";
ub4 prefetch = 10;
sword errr;
ub4 c1;
text c2[30];
OCIBind *bndhp;
OCIDefine *defnp1,
*defnp2;
for (int i = 0; i < MAXROWS; i++)
if (OCIDescriptorAlloc((dvoid *) envhp, (dvoid **) &(intArry),
(ub4) OCI_DTYPE_ROWID, (size_t) 0, (dvoid **) 0))
ShowMessage("FAILED: OCIDescriptorAlloc()\n");
return (OCI_ERROR);
if (OCIStmtPrepare (update_p, errhp,
mySql, strlen(mySql), OCI_NTV_SYNTAX, OCI_DEFAULT))
ShowMessage ("Prepare failed \n");
return (OCI_ERROR);
for (int k = 1; k <= 10; k++)
if (OCIBindByPos ( update_p,
&bndhp,
errhp,
k,
intArry,
sizeof(int),
SQLT_INT,
(ub2 *) 0,
(ub2 *) 0,
(ub4) 0,
(ub4) 0,
(ub4 *) 0,
(ub4) OCI_DEFAULT))
ShowMessage ("Bind failed \n");
return (OCI_ERROR);
if (errr = OCIStmtExecute(svchp,
update_p,
errhp,
(ub4) MAXROWS,
(ub4) 0,
(OCISnapshot *) NULL,
(OCISnapshot *) NULL,
(ub4) OCI_DEFAULT))
report_error(errhp);
ShowMessage ("Update failed \n");
return (OCI_ERROR);
delete[] intArry;
Can anybody tell me what is wrong? Thanks very much.
Changsong

Answer 1

Karl: Thanks a lot for your reply. I think you are right about context switch when calling a stored procedure.
I found even wrapping a 'begin' and 'end' around the query text in the call slows down a great deal (from 1 second to 5 seconds for 20000 inserts).
so a lot of the array binding benefits come from bulk-insert feature in oci, which is not allowed when calling a stored procedure. I've compared the performace using oci array binding to call a sp vs. traditional borland C++ builder BDE stored procedure component, and it is 23seconds vs 45 seconds. Still a lot of gain here, but compared with the bulk insert feature, I'm quite disappointed. My problem is most of the database transaction is done within some stored procedures and thus cann't take much advantage of bulk insert.
Changsong