From: Galen Charlton <gmc@esilibrary.com>
Date: Wed, 21 Dec 2016 21:32:26 +0000 (-0500)
Subject: LP#1651808: avoid a class of intermittent search failures
X-Git-Url: https://old-git.evergreen-ils.org/?a=commitdiff_plain;h=f67b07b4e57dad132bd50f25d5abaa8f74bb0cdd;p=working%2FEvergreen.git

LP#1651808: avoid a class of intermittent search failures

This patch fixes a bug where catalog searches can sometimes fail
with a PostgreSQL error that looks like this:

ERROR: type of parameter 56 (double precision) does not match that when preparing the plan (numeric)
CONTEXT: PL/pgSQL function search.query_parser_fts(integer,integer,text,integer[],integer[],integer,integer,integer,boolean,boolean,boolean,integer) line 319 at assignment

In particular, it ensures that the relevance values are coerced
to the Pg NUMERIC data type regardless of how the core query is
constructed; otherwise, it can sometimes end up as a double
precision value.  Because of how Pg backends cache query plans,
that change of type can result in the error above.

To test
-------
[1] (Optional) Configure the max_children values for open-ils.storage
    to permit only one drone, which in turn forces all catalog
    search requests to go through a single Pg backend.
[2] Set the default_preferred_language_weight opensrf.xml setting
    to 0.
[3] Perform a catalog search that has just a filter, e.g.,
    item_lang(eng).
[4] Perform a catalog search that includes search term, e.g.,
    cats
[5] The second search should fail.
[6] Apply the patch and try steps 3 and 4 again; this time, both
    searches should work.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>
---

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 4be8e93330..4c386e5e34 100644
--- 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
@@ -980,7 +980,7 @@ sub toSQL {
 $with
 SELECT  $key AS id,
         $agg_records,
-        ${rel}::NUMERIC AS rel,
+        (${rel})::NUMERIC AS rel,
         $rank AS rank, 
         FIRST(pubdate_t.value) AS tie_break,
         STRING_AGG(ARRAY_TO_STRING(pop_with.badges,','),',') AS badges,