Use Lucene's CoveringQuery to select percolate candidate matches #27271
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
martijnvg
added
:Search Relevance/Percolator
martijnvg
force-pushed
the
percolator_use_CoveringQuery
branch
from
67666ce to
dec88e1
Compare
extract all clauses from a conjunction query. When clauses from a conjunction are extracted the number of clauses is also stored in an internal doc values field (minimum_should_match field). This field is used by the CoveringQuery and allows the percolator to reduce the number of false positives when selecting candidate matches and in certain cases be absolutely sure that a conjunction candidate match will match and then skip MemoryIndex validation. This can greatly improve performance. Before this change only a single clause was extracted from a conjunction query. The percolator tried to extract the clauses that was rarest in order (based on term length) to attempt less candidate queries to be selected in the first place. However this still method there is still a very high chance that candidate query matches are false positives. This change also removes the influencing query extraction added via elastic#26081 as this is no longer needed because now all conjunction clauses are extracted. https://www.elastic.co/guide/en/elasticsearch/reference/6.x/percolator.html#_influencing_query_extraction Closes elastic#26307
martijnvg
force-pushed
the
percolator_use_CoveringQuery
branch
from
dec88e1 to
b4048b4
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
and extract all clauses from a conjunction query.
When clauses from a conjunction are extracted the number of clauses is
also stored in an internal doc values field (minimum_should_match field).
This field is used by the CoveringQuery and allows the percolator to
reduce the number of false positives when selecting candidate matches and
in certain cases be absolutely sure that a conjunction candidate match
will match and then skip MemoryIndex validation. This can greatly improve
performance.
Before this change only a single clause was extracted from a conjunction
query. The percolator tried to extract the clauses that was rarest in order
(based on term length) to attempt less candidate queries to be selected
in the first place. However this still method there is still a very high
chance that candidate query matches are false positives.
This change also removes the influencing query extraction added via #26081
as this is no longer needed because now all conjunction clauses are extracted.
https://www.elastic.co/guide/en/elasticsearch/reference/6.x/percolator.html#_influencing_query_extraction
PR for #26307