stats on cursor and query execution troubleshooting

Hi,

I'm looking for the statistic of memory, CPU, filesystem access while
executing some regular SQL query, and I want to compare them to
same kind of results while executing a cursor function.

The stat collector give me good results (sequencial scans , acceded
tuple .....) for regular query but nor for cursor (as explain in the
documentation)

For more results, i have activated some log level in the postgresql.conf :
show_query_stats = true

But I have some trouble in the results interpretation such as :

! system usage stats:

! 2.776053 elapsed 1.880000 user 0.520000 system sec

! [1.910000 user 0.540000 sys total]

! 0/0 [0/0] filesystem blocks in/out

! 5/1 [319/148] page faults/reclaims, 0 [0] swaps

! 0 [0] signals rcvd, 0/0 [0/0] messages rcvd/sent

! 0/0 [0/0] voluntary/involuntary context switches

! postgres usage stats:

! Shared blocks: 3877 read, 0 written, buffer hit rate = 0.00%

! Local blocks: 0 read, 0 written, buffer hit rate = 0.00%

! Direct blocks: 0 read, 0 written

Here is result done after fetching ALL a row with 178282 records in the
table.
looking at the i/o stat of linux I saw a filesystem access while
executing this request but not in the previous log !!!

! 0/0 [0/0] filesystem blocks in/out

I'm running postgresql 7.2.4 under redhat 7.2

Does am i wrong in my interpretation ?

Does any newest postgresql version could told me execution paln for a
fetch AND better stats ?

thx

Ps: please excuse my poor english

--
Alban Médici
R&D software engineer
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you can contact me @ :
http://www.netcentrex.net
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