After some inspection, here's the deal:
fetchall_arrayref always returns an arrayref, which is always a true value. The underlying cursor is finished when the referenced array is empty OR HAS LESS ELEMENTS THAN REQUESTED. Thus, the revised idiom:
while (my $rows = $sth->fetchall_arrayref( [@slice], $maxrows)) {
    last unless @$rows;
    
    # do stuff

    last if @$rows < $maxrows;
}

die $sth->errstr if $sth->errstr;

[download]
which doesn't look that great, with the two lasts and the always-true while $ref (unless some DBD decides to return undef on failure)... can anyone clean it up?

In reply to Re: DBI::fetchall_arrayref() error by Anonymous Monk
in thread DBI::fetchall_arrayref() error by blokhead

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.