MySQL Forums
Forum List  »  GIS

very slow insert, very large iowait
Posted by: Jean-Paul Le Fèvre
Date: May 24, 2005 05:52PM

I'm working with a big table (~20 millions row, 2 Gbytes)
and which will likely get bigger. There are indexes on the
columns. I've the impression that something is wrong when
I carry out massive insertions. The server is running on
a 4 CPU linux machine with 2 Gbytes of RAM.

Running top(1) I see that less than 10% of the CPU,
about 40% of the memory are used but that iowait is
always more than 240% (> 2 * 95% + 2 * 25%)

I don't know if I can get rid of this bottleneck.
My parameters are the following :

skip-locking
key_buffer_size = 512M
table_cache = 256
max_allowed_packet = 16M
sort_buffer_size = 128M
net_buffer_length = 8K
read_buffer_size = 1M
read_rnd_buffer_size = 8M
myisam_sort_buffer_size = 64M
bulk_insert_buffer_size = 64M
query_cache_size = 16M
preload_buffer_size = 16M
thread_cache = 8
thread_concurrency = 4

Options: ReplyQuote


Subject
Views
Written By
Posted
very slow insert, very large iowait
23762
May 24, 2005 05:52PM
13150
June 10, 2005 12:10PM
11890
November 25, 2005 09:35AM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.