LP#1999274: Improve Search Performance on Pg 12+

Use OFFSET as an optimization fence to keep newer PGs from trying to
fold the c_attr and b_attr CTEs into the main search query.

Signed-off-by: Mike Rylander <mrylander@gmail.com>
Signed-off-by: Jason Stephenson <jason@sigio.com>
Signed-off-by: Jane Sandberg <js7389@princeton.edu>

diff --git a/Open-ILS/src/perlmods/lib/OpenILS/Application/Storage/Driver/Pg/QueryParser.pm b/Open-ILS/src/perlmods/lib/OpenILS/Application/Storage/Driver/Pg/QueryParser.pm
index fe45ac1..b11a44c 100644 (file)
--- a/Open-ILS/src/perlmods/lib/OpenILS/Application/Storage/Driver/Pg/QueryParser.pm
+++ b/Open-ILS/src/perlmods/lib/OpenILS/Application/Storage/Driver/Pg/QueryParser.pm
@@ -1052,7 +1052,7 @@ sub toSQL {
 
         # WITH-clause just generates vis test
         $$flat_plan{with} .= "\n," if $$flat_plan{with};
-        $$flat_plan{with} .= "c_attr AS (SELECT (ARRAY_TO_STRING(ARRAY[$vis_test],'&'))::query_int AS vis_test FROM asset.patron_default_visibility_mask() x)";
+        $$flat_plan{with} .= "c_attr AS (SELECT (ARRAY_TO_STRING(ARRAY[$vis_test],'&'))::query_int AS vis_test FROM asset.patron_default_visibility_mask() x OFFSET 0)";
 
         $final_c_attr_test = 'EXISTS (SELECT 1 FROM asset.copy_vis_attr_cache WHERE record = m.source AND vis_attr_vector @@ c_attr.vis_test)';
     }
@@ -1097,7 +1097,7 @@ sub toSQL {
 
         # WITH-clause just generates vis test
         $$flat_plan{with} .= "\n," if $$flat_plan{with};
-        $$flat_plan{with} .= "b_attr AS (SELECT ($vis_test)::query_int AS vis_test FROM asset.patron_default_visibility_mask() x)";
+        $$flat_plan{with} .= "b_attr AS (SELECT ($vis_test)::query_int AS vis_test FROM asset.patron_default_visibility_mask() x OFFSET 0)";
 
         # These are magic numbers... see: search.calculate_visibility_attribute() UDF
         $final_b_attr_test = '(b_attr.vis_test IS NULL OR bre.vis_attr_vector @@ b_attr.vis_test)';