On Sun, Feb 27, 2011 at 2:43 AM, Josh Berkus
<josh@agliodbs.com> wrote:
On 2/25/11 5:31 AM, Sam Wong wrote:
> I found that "LIKE", "= ANY (...)", "LIKE .. OR LIKE .." against a text
> field used the index correctly, but not "LIKE ANY (...)". Would that be a
> bug?
No, it would be a TODO. This is a known limitation; it needs some
clever code to make it work, and nobody's written it.
came up with attached patch without thinking too much.
With this patch, the explain output for the same query is as below:
postgres=# explain select * from shipment_lookup where (UPPER(lookup) LIKE
ANY(ARRAY['SD1102228482%', 'ABCDEFGHIJK%']))
;e
QUERY PLAN
-------------------------------------------------------------------------------------------------
Seq Scan on shipment_lookup (cost=0.00..254057.36 rows=2000 width=14)
Filter: ((upper(lookup) ~~ 'SD1102228482%'::text) OR (upper(lookup) ~~ 'ABCDEFGHIJK%'::text))(2 rows)
postgres-#
The thing to be noted here is that the where clause "<pred> LIKE ANY ARRAY[..]"
has been converted into
(<pred> LIKE first_array_element) or (<pred> LIKE second_array_element) or ....
Please pass on your inputs.
Regards,
Chetan
--
Chetan Sutrave
Senior Software Engineer
EnterpriseDB Corporation
The Enterprise PostgreSQL Company
Phone: +91.20.30589523
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