Mark,
Note that selecting an index column means that Postgres fetches the whole
rows from disk. I think your performance problem is either: 1) slow disk or
2) index access of distributed data. If it¹s (1), there are plenty of
references from this list on how to check for that and fix it. If it¹
Mark,
This behavior likely depends on how the data is loaded into the DBMS. If
the records you are fetching are distributed widely among the 3M records on
disk, then
On 1/12/07 4:31 PM, "Mark Dobbrow" <[EMAIL PROTECTED]> wrote:
> Hello -
>
> I have a fairly large table (3 million records),
Depending on the available memory try increasing the shared buffers and
work_mem and see if that changes the query execution time. Also make sure
you have proper indices created and also if possible try doing partitions
for the table.
Once you post the EXPLAIN ANALYZE output that will certainly h
Have you run vacuum and analyze on the table? What version of Postgres are
you running? What OS are you using?
This looks like a straight forward query. With any database the first time
you run the query its going to be slower because it actually has to read off
disk. The second time its fast
What if we start a project where we define tests for PostgreSQL
overall performance and individual points with any database structure?
It could be done, throught a SQL logger and statistics, where we can
see complete processess and measure then after. We have many things to
measure, and something
On Fri, Jan 12, 2007 at 07:40:25PM -0500, Dave Cramer wrote:
> 5000 is pretty low, you need at least 1/4 of memory for an 8.1.x or
> newer server.
Is this the new "common wisdom"? It looks like at some point, someone here
said "oh, and it looks like you're better off using large values here for
On 12-Jan-07, at 7:31 PM, Mark Dobbrow wrote:
Hello -
I have a fairly large table (3 million records), and am fetching
10,000 non-contigous records doing a simple select on an indexed
column ie
select grades from large_table where teacher_id = X
This is a test database, so the number of
