Composite GiST indexes?

Christopher Kings-Lynne <chriskl@familyhealth.com.au> writes:

Is it possible to make a composite GiST index? I want to create an
index on a txtidx and a timestamp column - is that at all possible?

Yeah. If you have a problem with that, it's grounds for a bug report.
Note though that GiST can't handle entries with NULL in the first
column, so it's best to put a NOT NULL column first if possible.

regards, tom lane

Is it possible to make a composite GiST index? I want to create an
index on a txtidx and a timestamp column - is that at all possible?

OK, this is what I'm trying (7.3.4):

create index blah on forums_posts using gist(ftiidx, datetime);

ERROR: data type timestamp with time zone has no default operator class
for access method "gist"
You must specify an operator class for the index or define a
default operator class for the data type

I guess I can put an ops indicator in there, but I have no idea what to
try using...

Chris

Christopher Kings-Lynne <chriskl@familyhealth.com.au> writes:

OK, this is what I'm trying (7.3.4):
create index blah on forums_posts using gist(ftiidx, datetime);
ERROR: data type timestamp with time zone has no default operator class
for access method "gist"

That's got nothing to do with it being a two-column index --- it's that
GiST doesn't know what to do with a timestamptz, in any column.

I see that there is support for timestamp without time zone in
contrib/btree_gist --- probably it would be a simple matter to extend
that to timestamp with time zone. But it's not there today (much less
in 7.3 ;-))

regards, tom lane

On Mon, 5 Jan 2004, Christopher Kings-Lynne wrote:

Is it possible to make a composite GiST index? I want to create an
index on a txtidx and a timestamp column - is that at all possible?

you need to install contrib/btree_gist

btw, tsearch2 is much better than tsearch.
Check http://www.sai.msu.su/~megera/postgres/gist/tsearch/V2

Chris

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Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83

On Mon, 5 Jan 2004, Christopher Kings-Lynne wrote:

Is it possible to make a composite GiST index? I want to create an
index on a txtidx and a timestamp column - is that at all possible?

OK, this is what I'm trying (7.3.4):

create index blah on forums_posts using gist(ftiidx, datetime);

ERROR: data type timestamp with time zone has no default operator class
for access method "gist"
You must specify an operator class for the index or define a
default operator class for the data type

I guess I can put an ops indicator in there, but I have no idea what to
try using...

install contrib/btree_gist

Chris

---------------------------(end of broadcast)---------------------------
TIP 8: explain analyze is your friend

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83

Is it possible to make a composite GiST index? I want to create an
index on a txtidx and a timestamp column - is that at all possible?

OK, this is what I'm trying (7.3.4):

create index blah on forums_posts using gist(ftiidx, datetime);

ERROR: data type timestamp with time zone has no default operator
class
for access method "gist"
You must specify an operator class for the index or define a
default operator class for the data type

I guess I can put an ops indicator in there, but I have no idea what to
try using...

Chris

Install contrib/btree_gist so you can include the timestamp field in a gist index. Teodor Sigaev
suggested this on the openfts mailing list at:
http://sourceforge.net/mailarchive/message.php?msg_id=5349399

The btree_gist readme file says it supports the int2, int8, float4, float8, and timestamp data
types.

George Essig