I am new to storage technologies, but the plan is to build a customized SAN (storage area network). The intelligence will be how blocks are managed, such as automatic duplication or deduplication.
Read more…
In one and a half month, it will be a year since I started to use “ClustrMaps” for site statistics. And “phacai.com” has already served more than 20K (20,435 to be specific) visits! That’s around 80 visits per day.
Hope to double this number in the next year. Following is a screenshot I took a moment ago.
Let’s begin with an example. Assume two input files, “cdf1″ and “cdf2″:
Read more…
Now It’s hard to find some real performance numbers of PostgreSQL. The original link storing such information does not work anymore: http://developer.osdl.org/markw/postgrescvs/. Try it yourself, you will be redirected.
Read more…
Queries 9, 18, 21 are extremely slow. Query 18 is quite fast when I run it separately, but slowed down a lot in throughput test.
Read more…
I confirmed the observation by David Gruzman that for some queries in TPC-H, PostgreSQL is very slow because too much nested loop join is used. Using hash join instead will greatly improve performance.
Read more…
We know in the latest file system EXT4, when a file is deleted, a trim command will be automatically issued so that the underlying device will know which blocks are no longer used. SSDs will benefit from TRIM because the garbage collection overhead can be reduced.
Read more…
My ubuntu machine has two NICs. eth0 connects to the outside world, and eth1 connects to my internal network. To enable Internet access for internal network, follow these steps.
Read more…
DBT3 creates many indexes: one primary index on the primary key of each table, and the following secondary indexes:
Read more…
Recent Comments