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thanks a lot. I imagine this will help me a lot. I will give it a try!!!
One more question: in the explain output, what is that "Bitmap Heap Scan
on test"?, is it a bad thing (a table scan)? I would love to see the index
scan instead of this Heap scan... what does "Heap Scan" actually do here?
Bitmap Heap Scan on test (cost=2110.49..10491.57 rows=79766 width=6)
Recheck Cond: ((cola)::text = 'abc'::text)
-> Bitmap Index Scan on test_cola_idx (cost=0.00..2090.55 rows=79766
width=0)
Index Cond: ((cola)::text = 'abc'::text)
(4 rows)
Thanks again,
Jessica
----- Original Message ----
From: Charles Duffy <charles.duffy@[EMAIL PROTECTED]
>
To: Jessica Richard <rjessil@[EMAIL PROTECTED]
>
Cc: pgsql-admin@[EMAIL PROTECTED]
Friday, July 4, 2008 3:17:43 AM
Subject: Re: [ADMIN] slow delete...
> by the way, there is a foreign key on another table that references the
> primary key col0 on table test.
>
Try putting an index on the FK column in the other table. Analyse the
table. Test by starting a transaction then
issuing: explain analyze delete from test where cola = 'abc'. Should be
faster.
Charles Duffy
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<html><head><style type="text/css"><!-- DIV {margin:0px;}
--></style></head><body><div style="font-family:times new roman, new york,
times, serif;font-size:12pt"><div>thanks a lot. I imagine this will help me
a lot. I will give it a try!!!<br><br>One more question: in the explain
output, what is that "Bitmap Heap Scan on test"?, is it a bad thing (a
table scan)? I would love to see the index scan instead of this Heap
scan... what does "Heap Scan" actually do here?<br><br> Bitmap Heap
Scan on test (cost=2110.49..10491.57 rows=79766
width=6)<br> Recheck Cond: ((cola)::text =
'abc'::text)<br> -> Bitmap Index Scan on
test_cola_idx (cost=0.00..2090.55 rows=79766
width=0)<br> Index Cond:
((cola)::text = 'abc'::text)<br>(4 rows)<br><br>Thanks
again,<br>Jessica<br></div><div style="font-family: times new roman,new
york,times,serif; font-size: 12pt;"><br><div
style="font-family: arial,helvetica,sans-serif; font-size: 13px;">-----
Original Message ----<br>From: Charles Duffy
<charles.duffy@[EMAIL PROTECTED]
>To: Jessica Richard
<rjessil@[EMAIL PROTECTED]
>Cc: pgsql-admin@[EMAIL PROTECTED]
>Sent:
Friday, July 4, 2008 3:17:43 AM<br>Subject: Re: [ADMIN] slow
delete...<br><br>
> by the way, there is a foreign key on another table that references
the<br>> primary key col0 on table test.<br>><br><br>Try putting an
index on the FK column in the other table. Analyse the<br>table. Test by
starting a transaction then<br>issuing: explain analyze delete from test
where cola = 'abc'. Should be faster.<br><br><br>Charles Duffy<br><br>--
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href="mailto:pgsql-admin@[EMAIL PROTECTED]
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>)<br>To
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