QL: Reduce nesting of same bool queries #96265
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Improve transpilation of chained OR and AND queries by replacing boolQuery wrapping with extension of the queries inside the bool clause Fix elastic#96236
costin added >enhancement :Analytics/SQL 
| Pinging @elastic/es-ql (Team:QL) |
| Hi @costin, I've created a changelog YAML for you. |
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| {"bool":{"must":[{"wildcard":{"process_path":{"wildcard":"*x","boost":1.0}}}, | ||
| {"bool":{"must_not":[{"wildcard":{"process_path":{"wildcard":"*yx","boost":1.0}}}],"boost":1.0}}],"boost":1.0}} | ||
| {"bool":{"must_not":[{"wildcard":{"process_path":{"wildcard":"*yx","boost":1.0}}}],"boost":1.0}} |
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I'm wondering if this change is not affecting the score of a query that uses bools and returns the SCORE() as well.
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Confirmed with the search team that the two types of queries are equivalent as Lucene normalizes them to the same query (the one created above) when minimum_should_query is the default (1 - which it is).
| private final boolean isAnd; | ||
| private final Query left; | ||
| private final Query right; | ||
| private final List<Query> queries; |
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Imo, this change is a bit forced, conceptually speaking. A boolean query by definition is a boolean operation between two expressions, just like a math operation is. Having multiple expressions ALL linked together by either OR or AND seems like a specialized boolean query, MultiBoolQuery if you want. The BoolQueryBuilder in ES is built similarly, but is generalized: a list of must, a list of should, a list of filters etc.
I would have expected a solution around "flattening" the bool statements, but not touching the BoolQuery in this way.
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Balancing the tree would have been another alternative but I opted for the above because it simplifies the Lucene query which is what triggers the exception in the first place.
Based on napkin math a balanced tree has n-2 intermediate nodes (3 ORs - 1 intermediate node, 4 ORs - 2, 5 ORs - 3, etc..). This implementation truly flattens the OR to just 1 node regardless of how many clauses there are.
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| private static BoolQuery mutate(BoolQuery query) { | ||
| List<Function<BoolQuery, BoolQuery>> options = Arrays.asList( |
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This test doesn't fully reflect the changes in this PR, but I'm ok with it.
I've added two more tests - OR OR AND OR OR plus (OR OR) AND (OR OR OR) |
💚 Backport successful
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Improve transpilation of chained OR and AND queries by replacing boolQuery wrapping with extension of the queries inside the bool clause Fixes elastic#96236
4 participants
Improve transpilation of chained OR and AND queries by replacing
boolQuery wrapping with extension of the queries inside the bool clause
Fix #96236