(I've read a lot about 64-bit versus 32-bit OS/Apps, but this question is specifically in regards to databases.)
I'm trying to understand the pros and cons of 32-bit versus 64-bit databases, and namely, under what conditions that it starts to make sense to use 64-bit installations.
The database systems that I am interested in are: SQL Server 2008, MySQL, and PostgreSQL 9.0.
I have read that pre-9.0 versions of PostgreSQL only comes in 32-bit for Windows, and this article about running 32-bit PostgreSQL on 64-bit Windows clears up some of my confusion, but I'm looking for more info.
When would I benefit from using 64-bit databases (i.e. database size/disk space, available system memory, types of data sernarios that are known to benefit from it, which database engine being used, etc.)?
Best Answer
There is - today - no scenario where it makes sense to install a 32 bit SQL Server version if one has a chance.
Databases are specific in this - as they want to use a lot of memory as cache if necessary. A lot more than the meager 2gb / 3gb a 32 bit process can give them. PAE is not the same. Even ignoring limits, PAE memory is not equal to real memory for a SQL Server´(it is only used for ONE thing - caching db pages).
32 bit OS - is on the same level. it makes no sense on modern hardware at all to install a 32 bit OS.