Re: [GENERAL] Indexes on array columns
I have tried testing the perofmance on indexing array element using standard
btree and it doesn't help anything. It still costing alot.
create index idx_properties_address_4 on properties ((address_arr[4]))
does contrib/intarray effective for text array?
On 3/16/06, Oleg Bartunov oleg@sai.msu.su wrote:
contrib/intarray might help you
Oleg
On Wed, 15 Mar 2006, [EMAIL PROTECTED] wrote:
On Wed, Mar 15, 2006 at 09:36:04AM -0700, Brendan Duddridge wrote:
Hi,
Is it possible to put an index on an array column?
Apparently yes (I just did it as a test). However, consider the
following from the manual.
Tip: Arrays are not sets; searching for specific array elements
may be a sign of database misdesign. Consider using a separate
table with a row for each item that would be an array element. This
will be easier to search, and is likely to scale up better to large
numbers of elements.[1]
Arrays are attractive, but it seems they most often aren't the best
solution. FOr instance, I beleive I read somewhere that the index
will be on the whole array, and the individual elements are not
indexed, so
WHERE ary = {foo,bar}
might benefit from your index, but
WHERE 'foo' = ANY(ary)
probably wouldn't. At least that's the impression I got from
reading the archives of this list. I haven't done any testing of
it.
-karl
1. http://www.postgresql.org/docs/8.0/interactive/arrays.html#AEN5491
Thanks,
Brendan Duddridge | CTO | 403-277-5591 x24 | [EMAIL PROTECTED]
ClickSpace Interactive Inc.
Suite L100, 239 - 10th Ave. SE
Calgary, AB T2G 0V9
http://www.clickspace.com
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Regards,
Oleg
_
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83
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[GENERAL] Indexes on array columns
Hi,Is it possible to put an index on an array column?Thanks, Brendan Duddridge | CTO | 403-277-5591 x24 | [EMAIL PROTECTED] ClickSpace Interactive Inc. Suite L100, 239 - 10th Ave. SE Calgary, AB T2G 0V9 http://www.clickspace.com smime.p7s Description: S/MIME cryptographic signature
Re: [GENERAL] Indexes on array columns
On Wed, Mar 15, 2006 at 09:36:04AM -0700, Brendan Duddridge wrote:
Hi,
Is it possible to put an index on an array column?
Apparently yes (I just did it as a test). However, consider the
following from the manual.
Tip: Arrays are not sets; searching for specific array elements
may be a sign of database misdesign. Consider using a separate
table with a row for each item that would be an array element. This
will be easier to search, and is likely to scale up better to large
numbers of elements.[1]
Arrays are attractive, but it seems they most often aren't the best
solution. FOr instance, I beleive I read somewhere that the index
will be on the whole array, and the individual elements are not
indexed, so
WHERE ary = {foo,bar}
might benefit from your index, but
WHERE 'foo' = ANY(ary)
probably wouldn't. At least that's the impression I got from
reading the archives of this list. I haven't done any testing of
it.
-karl
1. http://www.postgresql.org/docs/8.0/interactive/arrays.html#AEN5491
Thanks,
Brendan Duddridge | CTO | 403-277-5591 x24 | [EMAIL PROTECTED]
ClickSpace Interactive Inc.
Suite L100, 239 - 10th Ave. SE
Calgary, AB T2G 0V9
http://www.clickspace.com
---(end of broadcast)---
TIP 6: explain analyze is your friend
Re: [GENERAL] Indexes on array columns
contrib/intarray might help you
Oleg
On Wed, 15 Mar 2006, [EMAIL PROTECTED] wrote:
On Wed, Mar 15, 2006 at 09:36:04AM -0700, Brendan Duddridge wrote:
Hi,
Is it possible to put an index on an array column?
Apparently yes (I just did it as a test). However, consider the
following from the manual.
Tip: Arrays are not sets; searching for specific array elements
may be a sign of database misdesign. Consider using a separate
table with a row for each item that would be an array element. This
will be easier to search, and is likely to scale up better to large
numbers of elements.[1]
Arrays are attractive, but it seems they most often aren't the best
solution. FOr instance, I beleive I read somewhere that the index
will be on the whole array, and the individual elements are not
indexed, so
WHERE ary = {foo,bar}
might benefit from your index, but
WHERE 'foo' = ANY(ary)
probably wouldn't. At least that's the impression I got from
reading the archives of this list. I haven't done any testing of
it.
-karl
1. http://www.postgresql.org/docs/8.0/interactive/arrays.html#AEN5491
Thanks,
Brendan Duddridge | CTO | 403-277-5591 x24 | [EMAIL PROTECTED]
ClickSpace Interactive Inc.
Suite L100, 239 - 10th Ave. SE
Calgary, AB T2G 0V9
http://www.clickspace.com
---(end of broadcast)---
TIP 6: explain analyze is your friend
Regards,
Oleg
_
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83
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TIP 2: Don't 'kill -9' the postmaster
