Brandon Keepers <bkeepers@xxxxxxxxx> writes: > Thanks for your quick response! I had actually just been trying that > (with 7.1) and came across another error: > NOTICE: ShmemAlloc: out of memory > NOTICE: LockAcquire: xid table corrupted > dumpBlobs(): Could not open large object. Explanation from backend: > 'ERROR: LockRelation: LockAcquire failed Ugh :-( How many blobs have you got, thousands? 7.0 stores each blob as a separate table, and I'll bet it is running out of lock table space to hold a lock on each one. My recollection is that we converted blob storage to a single pg_largeobject table precisely because of that problem. What you'll need to do to get around this is to export each blob in a separate transaction (or at least no more than a thousand or so blobs per transaction). It looks like pg_dumplo might be easier to hack to do things that way --- like pg_dump, it puts a BEGIN/COMMIT around the whole run, but it's a smaller program and easier to move those commands in. Another possibility is to increase the lock table size, but that would probably require recompiling the 7.0 backend. If you're lucky, increasing max_connections to the largest value the backend will support will be enough. If you've got many thousands of blobs there's no hope there, but if it's just a few thousand this is worth a try before you go hacking code. regards, tom lane
