Need to load the whole postgreSQL database into the RAM

Question

How do I put my whole PostgreSql database into the RAM for a faster access?? I have 8GB memory and I want to dedicate 2 GB for the DB. I have read about the shared buffers s

Answer 1

Perhaps something like a Tangosol Coherence cache if you're using Java.

Answer 2

if you are pulling data by id, use memcached - http://www.danga.com/memcached/ + postgresql.

Answer 3

Set up an old-fashioned RAMdisk and tell pg to store its data there.

Be sure you back it up well though.

Answer 4

I have asked myself the same question for a while. One of the disadvantages of PostgreSQL is that it does not seem to support an IN MEMORY storage engines as MySQL does...

Anyway I ran in to an article couple of weeks ago describing how this could be done; although it only seems to work on Linux. I really can't vouch for it for I have not tried it myself, but it does seem to make sense since a PostgreSQL tablespace is indeed assigned a mounted repository.

However, even with this approach, I am not sure you could put your index(s) into RAM as well; I do not think MySQL forces HASH index use with its IN MEMORY table for nothing...

I also wanted to do a similar thing to improve performance for I am also working with huge data sets. I am using python; they have dictionary data types which are basically hash tables in the form of {key: value} pairs. Using these is very efficient and effective. Basically, to get my PostgreSQL table into RAM, I load it into such a python dictionary, work with it, and persist it into db once in a while; its worth it if it is used well.

If you are not using python, I am pretty sure their is a similar dictionary-mapping data structure in your language.

Hope this helps!

Answer 5

With only an 8GB database, if you've already optimized all the SQL activity and you're ready solve query problems with hardware, I suggest you're in trouble. This is just not a scalable solution in the long term. Are you sure there is nothing you can do to make substantial differences on the software and database design side?