Drops in for any dated snapshot in dumps.wikimedia.org/archive — pages-articles.xml.bz2
and pages-meta-current.xml.bz2 (cur snapshot, single-revision-per-page) plus
pages-meta-history.xml.bz2 (multi_revision=True). abstract.xml feed yields
pre-distilled summaries at ~1/100th the chunk volume. Streams .bz2/.gz directly
via iterparse with bounded memory; same shard / resume contract as the SQL
source. Falls back to title-prefix namespace filtering when older export
schemas omit the per-page <ns> element (e.g. enwiki 20101011).
Makefile defaults target enwiki 20101011 (6.2 GB). Override with WP_XML_YEAR /
WP_XML_MONTH / WP_XML_DATE / WP_XML_LANG to fetch any other archived snapshot.