Mappings conflicts should not be ignored. If I read the history correctly, this
option was added when a mapping update to an existing field was considered a
conflict, even if the new mapping was exactly the same. Now that mapping updates
are smart enough to detect conflicting options, we don't need an option to
ignore conflicts.
The default `false` for `require_field_match` is a bit odd and confusing for users, given that field names get ignored by default and every field gets highlighted if it contains terms extracted out of the query, regardless of which fields were queries. Changed the default to `true`, it can always be changed per request.
Closes#10627Closes#11067
Our own fork of the lucene PostingsHighlighter is not easy to maintain and doesn't give us any added value at this point. In particular, it was introduced to support the require_field_match option and discrete per value highlighting, used in case one wants to highlight the whole content of a field, but get back one snippet per value. These two features won't
make it into lucene as they slow things down and shouldn't have been supported from day one on our end probably.
One other customization we had was support for a wider range of queries via custom rewrite etc. (yet another way to slow
things down), which got added to lucene and works much much better than what we used to do (instead of or rewrite, term
s are pulled out of the automata for multi term queries).
Removing our fork means the following in terms of features:
- dropped support for require_field_match: the postings highlighter will only highlight fields that were queried
- some custom es queries won't be supported anymore, meaning they won't be highlighted. The only one I found up until now is the phrase_prefix. Postings highlighter rewrites against an empty reader to avoid slow operations (like the ones that we were performing with the fork that we are removing here), thus the prefix will not be expanded to any term. What the postings highlighter does instead is pulling the automata out of multi term queries, but this is not supported at the moment with our MultiPhrasePrefixQuery.
Closes#10625Closes#11077
Most aggregations (terms, histogram, stats, percentiles, geohash-grid) now
support a new `missing` option which defines the value to consider when a
field does not have a value. This can be handy if you eg. want a terms
aggregation to handle the same way documents that have "N/A" or no value
for a `tag` field.
This works in a very similar way to the `missing` option on the `sort`
element.
One known issue is that this option sometimes cannot make the right decision
in the unmapped case: it needs to replace all values with the `missing` value
but might not know what kind of values source should be produced (numerics,
strings, geo points?). For this reason, we might want to add an `unmapped_type`
option in the future like we did for sorting.
Related to #5324
Previously, collate feature would be executed on all shards of an index using the client,
this leads to a deadlock when concurrent collate requests are run from the _search API,
due to the fact that both the external request and internal collate requests use the
same search threadpool.
As phrase suggestions are generated from the terms of the local shard, in most cases the
generated suggestion, which does not yield a hit for the collate query on the local shard
would not yield a hit for collate query on non-local shards.
Instead of using the client for collating suggestions, collate query is executed against
the ContextIndexSearcher. This PR removes the ability to specify a preference for a collate
query, as the collate query is only run on the local shard.
closes#9377
Add methods to operate on multi-valued fields in the expressions language.
Note that users will still not be able to access individual values
within a multi-valued field.
The following methods will be included:
* min
* max
* avg
* median
* count
* sum
Additionally, changes have been made to MultiValueMode to support the
new median method.
closes#11105
These clauses filter the document space without affecting scoring and map to
Lucene's BooleanClause.Occur.FILTER. The `filtered` query is now deprecated and
```json
{
"filtered": {
"query": { //query },
"filter": { //filter }
}
}
```
should be replaced with
```json
{
"bool": {
"must": { //query },
"filter": { //filter }
}
}
```
A few meta fields can currently be set within a document's source.
However, the recommended way to set meta fields like this is through
the api, and setting within the document can be a performance trap
(e.g. needing to find _id in order to route the document).
This change removes the ability to set meta fields within
a document source for 2.0+ indexes.
closes#11051closes#11074
As a follow up to #10870, this removes support for
index templates on disk. It also removes a missed
place still allowing disk based mappings.
closes#11052
Meta fields were locked down to not allow exotic options to the
underlying field types in #8143. This change fixes the docs
to no longer refer to the old settings.
closes#10879
This commit makes queries and filters parsed the same way using the
QueryParser abstraction. This allowed to remove duplicate code that we had
for similar queries/filters such as `range`, `prefix` or `term`.
Getting this to work would be a lot of work (creating two different
repositories, having another GPG key, integrating this into our build).
Closes#6498
Removes the More Like This API, users should now use the More Like This query.
The MLT API tests were converted to their query equivalent. Also some clean
ups in MLT tests.
Closes#10736Closes#11003
Previously, we were using the "statistical", technically accurate name. Instead, we
should probably use the name that people are familiar with, e.g. "Holt Winters" instead
of "triple exponential". To that end:
- `single_exp` becomes `ewma` (exponentially weighted moving average)
- `double_exp` becomes `holt`
When the `triple_exp` is added, it will be called `holt_winters`.
Current features (eg. update API) and future features (eg. reindex API)
depend on _source. This change locks down the field so that
it can no longer be disabled. It also removes legacy settings
compress/compress_threshold.
closes#8142closes#10915
Clinton Gormley
Simon Willnauer
Adrien Grand
javanna
Jun Ohtani
Martijn van Groningen
Britta Weber
Lee Hinman
Areek Zillur
Jack Conradson
Ryan Ernst
Igor Motov
Andrew Selden
josephwolnskipn
Alex Ksikes
Alexander Reelsen
Colin Goodheart-Smithe
Zachary Tong
Pascal Borreli
aleph-zero