0
votes
0answers
44 views

Oracle 11.2 Explain Plan takes too long

I'm using Oracle 11.2 SE on a 16GB Xeon E3 Linux machine as well as 11.2 XE on a 8GB i7 Win8 machine: SELECT banner FROM v$version: Oracle Database 11g Release 11.2.0.4.0 - 64bit Production PL/SQL ...
0
votes
0answers
136 views

MySQL: how to determine key_len and its role in performance improvement of a query

I have a query, below is the structure of the table: CREATE TABLE `jos_tag_rules_fields` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL DEFAULT '', `label` varchar(255) ...
4
votes
2answers
2k views

Help to understand explain plan in Oracle

I am running a query in some big tables, and although it runs fine even tough is a lot of data, I'd like to understand what part of it weighs on the execution. Unfortunately I am not too good with ...
3
votes
1answer
507 views

Measuring the relative performance of queries given the assertion that “cost” isn't reliable

The cost field is a comparative cost that is used internally to determine the best cost for particular plans. The costs of different statements are not really directly comparable. Source Does ...