After all the changes of the memory parameters the same operation(without the copy utility) didnt run much faster - it took one minute less. I made a test with the copy command (without the 'with binary') and it took 1.5 hours to create the dumpfile in my local postgresql server. Then I tried to run the copy from the local dump and it is already running two hours and it didnt even finish. I looked at the server log and I saw that I run the copy command at 13:18:05, 3 minutes later checkpoint started and completed and there are no messages in the log after that. What can I do ? Improving the memory parameters and the memory on the server didnt help and for now the copy command doesnt help either.
2017-08-15 20:14 GMT+03:00 Scott Marlowe <scott.marl...@gmail.com>: > On Tue, Aug 15, 2017 at 4:06 AM, Mariel Cherkassky > <mariel.cherkas...@gmail.com> wrote: > > Hi, > > So I I run the cheks that jeff mentioned : > > \copy (select * from oracle_remote_table) to /tmp/tmp with binary - 1 > hour > > and 35 minutes > > So 26G takes 95 minutes, or 27 MB/minute or 456k/second? Sound about > right (it's early, I haven't had enough coffee please check my math). > That's pretty slow unless you're working across pretty big distances > with mediocre connections. My home internet downloads about 100MB/s > by comparison. > > > \copy local_postresql_table from /tmp/tmp with binary - Didnt run because > > the remote oracle database is currently under maintenance work. > > You shouldn't need the remote oracle server if you've already copied > it over, you're just copying from local disk into the local pgsql db. > Unless I'm missing something. > > > So I decided to follow MichaelDBA tips and I set the ram on my machine to > > 16G and I configured the effective_cache memory to 14G,tshared_buffer to > be > > 2G and maintenance_work_mem to 4G. > > Good settings. Maybe set work_mem to 128MB or so while you're at it. > > > I started running the copy checks again and for now it coppied 5G in 10 > > minutes. I have some questions : > > 1)When I run insert into local_postresql_table select * from > > remote_oracle_table I insert that data as bulk to the local table or row > by > > row ? If the answer as bulk than why copy is a better option for this > case > > ? > > insert into select from oracle remote is one big copy, but it will > take at least as long as copying from oracle to the local network > took. Compare that to the same thing but use file_fdw on the file > locally. > > > 2)The copy from dump into the postgresql database should take less time > than > > the copy to dump ? > > Yes. The copy from Oracle to your local drive is painfully slow for a > modern network connection. > > > 3)What do you think about the new memory parameters that I cofigured ? > > They should be OK. I'm more worried about the performance of the io > subsystem tbh. >
