Release Overview for 1.4.19

This page contains a high level description of the most notable changes in this release. For full details of user-visible changes, see the NEWS files in each module:

• ​xapian-core
• ​omega
• ​xapian-bindings

See also the full list of bug reports marked as fixed in this release.

Matcher

• Fetch wdf upper bound from postlist which avoids an extra postlist table cursor seek per weighted query term, and also means we now use a per-shard wdf upper bound for local shards which will in typically give a tighter weight upper bound which will tend to make various other matcher optimisations more effective. Eric Wong reported this speeds up a particularly slow case from ~2 minutes to ~3 seconds.

With this change, OP_ELITE_SET can now select a different subset of terms for each shard regardless of shard type (previously this only happened for remote shards).

• Only check if the database has positional information when the query uses positional information. This should help improve notmuch delete performance.

PHP7

• configure: We now reject PHP8 since it isn't currently supported by a released version of SWIG. SWIG 4.1.0 will supports PHP8.

OmegaScript

• The JSON produced by $jsonobject no longer contains newlines, which makes it usable as a single line serialisation format without post-processing.

Omega Templates

• Fix topterms template to not trigger early matching. We were checking $msize before including the query template, but doing so would trigger the query to be run, which means that settings early in the query template which should affect the result (such as $setmap{prefix,...}) were being ignored when the topterms template was used. Partly addresses #815.