I imported some millions of rows into a table:
sql>select part, count(*) from frag group by part order by part; +------+-----------+ | part |count_node | +======+===========+ | 1 | 25205085 | | 2 | 25618423 | | 3 | 27380780 | | 4 | 26963069 | | 5 | 25661196 | | 6 | 27021186 | | 7 | 26058891 | | 8 | 28092822 | | 9 | 27528646 | | 10 | 26429092 | | 11 | 25194504 | | 12 | 25136210 | | 13 | 25105453 | | 14 | 24860071 | | 16 | 20672348 | | 17 | 19138139 | +------+-----------+
then I stopped the database, and wanted to start it back up to see how quickly it would come up. it took a few minutes to come up while it was comitting uncomitted transactions. When i started it up the space usage looked like this:
251721152 ./var/MonetDB5/dbfarm (251gb) 24181152 ./var/MonetDB5/sql_logs (24gb)
after a few minutes it became like this:
249855172 ./var/MonetDB5/dbfarm (249gb) 12 ./var/MonetDB5/sql_logs
however when it came up, i guess the data became corrupted because look at what happened to my query results now:
sql>select part, count(*) from frag group by part order by part; +------+-----------+ | part |count_node | +======+===========+ | 1 | 25205085 | | 0 | 361722691 | | 17 | 19138139 | | 18 | 21414794 | +------+-----------+
there are total about 427 M rows, of which 361.7M are corrupted.
There is nothing in the merovingian.log file at all since stop/start of database.
Can someone advise what to do with this? 1. if possible to recover data, please let me know 2. otherwise what can I do to prevent this in the future? this is a huge roadblock.