Re: [Sqlgrey-users] Using multiple Connect tables

[Kenneth M. <kt...@ri...>]

On Thu, Mar 29, 2007 at 03:47:40PM -0400, Dave Strickler wrote:
>  
> However, I have a larger question that asks, "what do we do when the Connect table reaches 10 million, or 20 million?" How large can it grow before I'm in trouble? Since I don't know it's upper limits, I fear I may run into them randomly one day.
>  
Dave,

Like Lionel stated, you need to avoid VACUUM FULL and use just a regular
VACUUM instead. Autovacuum will run it for you and ANALYZE your tables
when needed. As I previously mentioned, you should reduce the size of
the autovacuum thresholds so that it will work when a smaller fraction
of the table has changed. The size at which performance will start to
drop is when the working set of data that is being changed is larger
than your system cache footprint. The lower bound is going to be the
size of the index for the connection table, since that is what is used
to speed access to the data in the table. If you calculate the average
size of each field that comprises the index and add them together. That
will give you the size of a typical index entry. Then divide that number
into the system memory size to generate an absolute lower bound on the
size. 

Ken