It looks like my "out of memory" errors may have been caused by long
running txs. At least I have one at the moment that seems to be; there
is a single xid in sl_log_1 that has 45000 rows. The slon process dies
every time it tries to process it.

Is there a way around this? Is the slon process reading the whole tx
into memory?

Any help would bre appreciated...

FWIW, the counts by XID from sl_log_1 are:

 log_origin | log_xid | count
------------+---------+-------
          3 | 4795427 | 45228
          3 | 4795451 |     6
          3 | 4795452 |     6
          3 | 4795481 |     6
          3 | 4795501 |     6
          3 | 4795505 |     6
....etc for 8000 more rows.

The large single xid has about 1.5GB of data and was caused by doing an
"insert...select..." statement.

Can slon be hacked to avoid buffering so much in memory?