Tom Lane wrote:
>
> mlw <[EMAIL PROTECTED]> writes:
> > cdinfo=# explain select * from ztitles where artistid = 0 ;
> > NOTICE: QUERY PLAN:
>
> > Index Scan using ztitles_artistid_ndx on ztitles (cost=0.00..5915.01
> > rows=3163 width=296)
>
> > When postmaster is started without "-o -fs" I get this:
>
> > cdinfo=# explain select * from ztitles where artistid = 0 ;
> > NOTICE: QUERY PLAN:
>
> > Seq Scan on ztitles (cost=0.00..4740.75 rows=3163 width=296)
>
> How many tuples are in the table? How many are actually returned
> by this query? Also, what do you get from
>
> select attname,attdisbursion,s.*
> from pg_statistic s, pg_attribute a, pg_class c
> where starelid = c.oid and attrelid = c.oid and staattnum = attnum
> and relname = 'ztitles';
I have attached the output.
btw anyone trying this query should use: "attdispersion"
The explain I gave, there are no records that actually have an artistid
of 0. However, I will show the explain with a valid artistid number.
This is without "-o -fs"
cdinfo=# explain select * from ztitles where artistid = 100000220 ;
NOTICE: QUERY PLAN:
Seq Scan on ztitles (cost=0.00..4740.75 rows=3163 width=296)
EXPLAIN
And this is with "-o -fs"
cdinfo=# explain select * from ztitles where artistid = 100000220 ;
NOTICE: QUERY PLAN:
Index Scan using ztitles_artistid_ndx on ztitles (cost=0.00..5915.01
rows=3163 width=296)
EXPLAIN
select count(*) from ztitles where artistid = 100000220 ;
count
-------
16
(1 row)
--
http://www.mohawksoft.com
attname | attdispersion | starelid | staattnum | staop | stanullfrac |
stacommonfrac | stacommonval | staloval | stahival
------------+---------------+----------+-----------+-------+-------------+---------------+------------------------+--------------------------+-------------------
muzenbr | -1 | 19274 | 1 | 97 | 0 |
4.72277e-06 | 397705 | 58608 | 399022
artistid | 0.0477198 | 19274 | 2 | 97 | 0 |
0.149362 | 100050450 | 100000000 | 100055325
cat2 | 0.618418 | 19274 | 3 | 1066 | 0 |
0.763058 | Performer | Boxed Set | Single
cat3 | 0.0459786 | 19274 | 4 | 1066 | 4.72277e-06 |
0.145367 | International | Blues | Sound Effects
cat4 | 0.308324 | 19274 | 5 | 1066 | 4.72277e-06 |
0.50827 | | | Zydeco
performer | 0.0477281 | 19274 | 6 | 1066 | 4.72277e-06 |
0.149381 | Various Artists | "Blue" Gene Tyranny | underGRIND
performer2 | 0.0477198 | 19274 | 7 | 1066 | 4.72277e-06 |
0.149362 | Various Artists | "Chuscales", Jose Valle | underGRIND
title | 1.88982e-05 | 19274 | 8 | 1066 | 4.72277e-06 |
9.44555e-05 | Good Old Country | ! | Zzzzzz... [EP] *
artist1 | 0.770286 | 19274 | 9 | 1066 | 4.72277e-06 |
0.864182 | | | w
engineer | 0.719466 | 19274 | 10 | 1066 | 4.72277e-06 |
0.831534 | | | ob Bullock
producer | 0.586756 | 19274 | 11 | 1066 | 4.72277e-06 |
0.740488 | | | Zvika Nadaf
labelname | 0.000490215 | 19274 | 12 | 1066 | 4.72277e-06 |
0.00242751 | Rykodisc USA | | `A`A`Li`I Records
catalog | 0.00114041 | 19274 | 13 | 1066 | 4.72277e-06 |
0.00557759 | 1 | | sftri325
distribut | 0.0342314 | 19274 | 14 | 1066 | 4.72277e-06 |
0.11669 | Universal Distribution | (Independently by Label) | n/a
released | 0.0331312 | 19274 | 15 | 1066 | 4.72277e-06 |
0.113828 | n/a | 01/01/1986 | n/a
origrel | 0.0266312 | 19274 | 16 | 1066 | 4.72277e-06 |
0.0961651 | 2000 | 1911 | n/a
nbrdiscs | 0.931311 | 19274 | 17 | 1066 | 4.72277e-06 |
0.961169 | 1 | 01 | 9
spar | 0.84807 | 19274 | 18 | 1066 | 4.72277e-06 |
0.912166 | n/a | *N* | n/a
minutes | 0.778454 | 19274 | 19 | 1066 | 4.72277e-06 |
0.86933 | | | 99
seconds | 0.778454 | 19274 | 20 | 1066 | 4.72277e-06 |
0.86933 | | | 98
monostereo | 0.854336 | 19274 | 21 | 1066 | 4.72277e-06 |
0.915935 | Stereo | Mono | n/a
studiolive | 0.878293 | 19274 | 22 | 1066 | 4.72277e-06 |
0.930221 | Studio | Live | n/a
available | 0.632032 | 19274 | 23 | 1058 | 4.72277e-06 |
0.756938 | Y | N | Y
previews | 0.798323 | 19274 | 24 | 1066 | 4.72277e-06 |
0.881742 | | | 99954
pnotes | 0.310707 | 19274 | 25 | 1066 | 4.72277e-06 |
0.510617 | | | 99986
acd | 0.998235 | 19274 | 26 | 1066 | 4.72277e-06 |
0.999117 | A | A | D
(26 rows)
