Tom Lane wrote:
"Ray" <ray_siu@ge-ts.com.hk> writes:
CREATE INDEX idx_doc_substr_doc_urn ON doc USING btree (SUBSTR(doc_urn,10));
ERROR: parser: parse error at or near "10" at character 68
This will work in 7.4, but not older releases.
Can't you just use a SQL function that calls the substr function? I have done that with date functions before
like:
CREATE OR REPLACE FUNCTION get_month(text) returns double precision AS ' SELECT date_part('month',$1);
' LANGUAGE 'SQL' IMMUTABLE;
CREATE INDEX get_month_idx on foo(get_month(date_field)); Or in this case:
CREATE OR REPLACE FUNCTION sub_text(text) returns text AS '
SELECT SUBSTR($1,10) from foo;
' LANGUAGE 'SQL' IMMUTABLE;
CREATE INDEX sub_text_idx ON foo(sub_text(doc_urn));
This works on 7.3.6???
Sincerely,
Joshua D. Drake
regards, tom lane
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