On 1/30/07, Tom Lane <[EMAIL PROTECTED]> wrote:
"Pavan Deolasee" <[EMAIL PROTECTED]> writes: > The stack usage for toast_insert_or_update() may run into several KBs since > the MaxHeapAttributeNumber is set to a very large value of 1600. The usage > could anywhere between 28K to 48K depending on alignment and whether its a > 32-bit or a 64-bit machine. So? The routine is not re-entrant so I don't see that the stack space is a big problem. It's coded that way to avoid palloc/pfree cycles...
I always thought that it would be costlier to have a repeated stack allocation/deallocation of many KBs than dynamically allocating a small percentage of that. But I might be wrong. In fact, a small test I ran showed that mallloc/free is more costly. So may be are good. Btw, I noticed that the toast_insert_or_update() is re-entrant. toast_save_datum() calls simple_heap_insert() which somewhere down the line calls toast_insert_or_update() again. It looks a bit surprising, haven't look into detail though. Thanks, Pavan -- EnterpriseDB http://www.enterprisedb.com
