I have to agree with friedo. This sounds like an index issue. What kind of indexes do you have on catalog and pivot? If you don't know what I am talking about, then you need to educate yourself on indexes.
Here is how you would create some indexes on these two tables. Enter these in the mysql command line tool. 
create index c_atldp on catalog ( author, titulo, label, description, 
+price )

create index a_atldp on author ( author, titulo, label, description, p
+rice )

[download]

You can create several different types of indexes depending on how and what kind of queries you are writing and a full discussion of indexes is OT. Sometimes you need to write new ones for a new type of query.
JamesNC

In reply to Re: mysql's join too slow; using Perl to compare two tables by JamesNC
in thread mysql's join too slow; using Perl to compare two tables by Andre_br

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.