"Matt Magoffin" <postgresql.org@msqr.us> writes: > 2) Even if I could have an xpath() result return an array with multiple > values, like {value1,value2,value3} I wasn't able to define a GIN index > against the xml[] type. Should this be possible? Dunno about your other questions, but the answer to this one is "no" --- AFAICS there is no indexing support of any kind for the xml type in 8.3. Try casting to text[] instead. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq

"Matt Magoffin" <postgresql.org@msqr.us> writes: > Should the xpath() function return 3 individual text nodes like this: > /elem[@key="mykey"]/text() => { > value1, > value2, > value3 > } > rather than concatenating these into a single text node result? AFAICT that's exactly what it does. regression=# select xpath('//foo[@key="mykey"]/text()', '<value>ABC<foo key="mykey">XYZ</foo></value><foo key="mykey">RST</foo><foo>DEF</foo>'); xpath ----------- {XYZ,RST} (1 row) regression=# Of course this is of type xml[], but you can cast to text[] and then index. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@postgresql.org so that your message can get through to the mailing list cleanly

"Matt Magoffin" <postgresql.org@msqr.us> writes: > Ugh, you're right of course! Somehow I had this wrong. So I tried to > create an index on the xml[] result by casting to text[] but I got the > "function must be immutable" error. Is there any reason the xml[] to > text[] cast is not immutable? Hmm ... I see that xmltotext() is marked 'stable' in pg_proc.h, but texttoxml() is marked 'immutable', which is at best inconsistent. It looks to me like they both depend on the GUC setting "xmloption", which would mean they should both be stable. Peter, is there a bug there? Also, is there a way to get rid of the GUC dependency so that there's a reasonably safe way to index XML values? regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq