Обсуждение: ODBC and palloc ...
After a lot of changes I've compiled,linked and tested (regression) my PostgreSQL installation no HPUX 9.*. I've also built and installed the ODBC driver and I get Ms Access error which the PostgresSQL server log in "palloc failure : memory exausted". Is this a server bug or ODBC driver bug ? ---- Davide Libenzi at : Maticad s.r.l. Via Della Giustizia n.9 Fano (PS) 61032 Italy Tel.: +39-721-808308 (ra) Fax: +39-721-808309 Email: <davidel@maticad.it> WWW: <http://www.maticad.it>
Davide Libenzi wrote: > > After a lot of changes I've compiled,linked and tested (regression) my > PostgreSQL installation no HPUX 9.*. > > I've also built and installed the ODBC driver and I get Ms Access error > which the PostgresSQL server log in "palloc failure : memory exausted". > > Is this a server bug or ODBC driver bug ? > I am assuming you have a fairly new odbc driver (6.30.0248 is the latest) and not the old postodbc. BTW, on our website (www.insightdist.com/psqlodbc) we have the DLL and a full install EXE for win32 so you wouldn't have to build it yourself from the source code if you didn't want to. The palloc failure usually occurs because Access uses the multiple OR query (select ... where a=1 OR a=2 OR a=3...) to access the recordset. The backend does not handle this very well and it is already well known on the TODO list. There are several possibilities to get past this: 1. Use a non-updateable table (by setting the driver readonly option, or by not specifying any unique identifiers). 2. For a query, use a snapshot recordset in the query properties. 3. Show the OID column in the drivers advanced datasource options and use that alone to index on. You should create an index on it too. This is still slow, but at least shouldn't crash. Other possibilities: In house, Dave made a patch to postgres which rewrites the multiple OR query into a UNION query, which works great and its fast! We may make this patch available evntually on our website. Byron
> Davide Libenzi wrote: > > > > After a lot of changes I've compiled,linked and tested (regression) my > > PostgreSQL installation no HPUX 9.*. > > > > I've also built and installed the ODBC driver and I get Ms Access error > > which the PostgresSQL server log in "palloc failure : memory exausted". > > > > Is this a server bug or ODBC driver bug ? > > > > I am assuming you have a fairly new odbc driver (6.30.0248 is the > latest) and not the old postodbc. BTW, on our website > (www.insightdist.com/psqlodbc) we have the DLL and a full install EXE > for win32 so you wouldn't have to build it yourself from the source code > if you didn't want to. > > The palloc failure usually occurs because Access uses the multiple OR > query (select ... where a=1 OR a=2 OR a=3...) to access the recordset. > The backend does not handle this very well and it is already well known > on the TODO list. > > There are several possibilities to get past this: > 1. Use a non-updateable table (by setting the driver readonly option, or > by not specifying any unique identifiers). > 2. For a query, use a snapshot recordset in the query properties. > 3. Show the OID column in the drivers advanced datasource options and > use that alone to index on. You should create an index on it too. This > is still slow, but at least shouldn't crash. > > Other possibilities: > > In house, Dave made a patch to postgres which rewrites the multiple OR > query into a UNION query, which works great and its fast! We may make > this patch available evntually on our website. I am thinking about this right now, and will post an analysis within the next day. -- Bruce Momjian | 830 Blythe Avenue maillist@candle.pha.pa.us | Drexel Hill, Pennsylvania 19026 + If your life is a hard drive, | (610) 353-9879(w) + Christ can be your backup. | (610) 853-3000(h)