I have been experimenting with SQLBulkOperations to see if it is faster
at inserting rows than using individual insert statements.
But when I run the attached(bo.c) example program it segfaults(note,
this program works correctly with an Oracle ODBC connection).
The program requires the following table.
create table customer
cust_num integer not null,
Also the odb_db_open function call uses a hard coded DSN=pg_cdc_w,
username=username and password=password.
I am using the latest versions of pgsql+postgres on Linux i.e.
I turned on the ODBC debug log and added some log output to the driver
and found that the segfault is occurring in the results.c:SC_pos_add
In particular the log shows
POS ADD fi=(nil) ti=(nil)
and the segfault occurs on this line:-
if (*used != SQL_IGNORE && fi[i]->updatable)
So fi is NULL but is being referenced.
I did a bit more checking and found that parse_statement sets up
parse_statement(s.stmt, TRUE); /* not preferable */
after parse_statement gets past this segfault.
But then another segfault occurs in the results.c:positioned_load
function as stmt->load_stmt is NULL
so strlen(stmt->load_stmt) segfaults.
The code is complicated and I have not been able to determine how to fix
this, it seems likely to me that even the fi fix may be covering up an
earlier problem somewhere else in the code.
Does anybody use SQLBulkOperations to load data?
If so is it faster than individual inserts?
The postgres driver included with unixODBC fails as well but it at least
return a standard ODBC error so I suppose it doesn't support
SQLBulkOperations, I understand the unixODBC driver is defunct anyway.
I have noticed that the unixODBC postgres driver is significantly
quicker when using a prepared insert to insert 100,000 rows.
Specifically psqlodbc takes about 75% longer, but this is reduced to
about 45% longer when 'UseServerSidePrepare = 1' is set. Indeed it was
this speed difference that prompted me to try SQLBulkOperation in the
Are there any other setting that may improve the speed of the psqlodbc
Any ideas why the old unixODBC driver is so much faster?
Description: text/x-csrc (5.2 KB)
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