-
Notifications
You must be signed in to change notification settings - Fork 19
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
1 parent
3c5cfe9
commit ec8a561
Showing
3 changed files
with
218 additions
and
68 deletions.
There are no files selected for viewing
This file contains 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
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,109 @@ | ||
| --- | ||
| title: 'Release 3.2: 🔎 Knowing what to optimize' | ||
| --- | ||
|
|
||
| For this release, we mainly focused on improving tooling to more easily track down performance issues. | ||
| Concretely, we improved our query explain output, | ||
| started running multiple benchmarks in our CI to avoid performance regressions, | ||
| and applied several performance improvements that were identified following these changes. | ||
|
|
||
| <!-- excerpt-end --> | ||
|
|
||
| ## 🔎 Query explain improvements | ||
|
|
||
| Comunica has had several [query explain functionalities](/docs/query/advanced/explain/) for a while now, | ||
| to show how a query is parsed, optimized (logical), and executed (physical). | ||
| However, the physical plan output tended to be very verbose, which made it difficult to draw conclusions from. | ||
|
|
||
| In this update, the physical plan output has undergone three main changes: | ||
|
|
||
| 1. The output from joins (especially Bind Joins) are _compacted_, so that recurring patterns in sub-plans are not repeated. Instead, a counter is added showing how many times a certain sub-plan was executed. | ||
| 2. The default output is a compact text representation instead of the previous JSON output. (The old JSON representation is still available when passing the `physical-json` explain value) | ||
| 3. Additional metadata is emitted, such as cardinalities and execution times. | ||
|
|
||
| For example, outputs such as the following can now be obtained: | ||
|
|
||
| ```bash | ||
| $ node bin/query.js https://fragments.dbpedia.org/2016-04/en \ | ||
| -q 'SELECT ?movie ?title ?name | ||
| WHERE { | ||
| ?movie dbpedia-owl:starring [ rdfs:label "Brad Pitt"@en ]; | ||
| rdfs:label ?title; | ||
| dbpedia-owl:director [ rdfs:label ?name ]. | ||
| FILTER LANGMATCHES(LANG(?title), "EN") | ||
| FILTER LANGMATCHES(LANG(?name), "EN") | ||
| }' --explain physical | ||
| ``` | ||
| ```text | ||
| project (movie,title,name) | ||
| join | ||
| join-inner(bind) bindOperation:(?g_0 http://www.w3.org/2000/01/rdf-schema#label "Brad Pitt"@en) bindCardEst:~2 cardReal:43 timeSelf:2.567ms timeLife:667.726ms | ||
| join compacted-occurrences:1 | ||
| join-inner(bind) bindOperation:(?movie http://dbpedia.org/ontology/starring http://dbpedia.org/resource/Brad_Pitt) bindCardEst:~40 cardReal:43 timeSelf:6.011ms timeLife:641.139ms | ||
| join compacted-occurrences:38 | ||
| join-inner(bind) bindOperation:(http://dbpedia.org/resource/12_Monkeys http://dbpedia.org/ontology/director ?g_1) bindCardEst:~1 cardReal:1 timeSelf:0.647ms timeLife:34.827ms | ||
| filter compacted-occurrences:1 | ||
| join | ||
| join-inner(nested-loop) cardReal:1 timeSelf:0.432ms timeLife:4.024ms | ||
| pattern (http://dbpedia.org/resource/12_Monkeys http://www.w3.org/2000/01/rdf-schema#label ?title) cardEst:~1 src:0 | ||
| pattern (http://dbpedia.org/resource/Terry_Gilliam http://www.w3.org/2000/01/rdf-schema#label ?name) cardEst:~1 src:0 | ||
| join compacted-occurrences:2 | ||
| join-inner(multi-empty) timeSelf:0.004ms timeLife:0.053ms | ||
| pattern (http://dbpedia.org/resource/Contact_(1992_film) http://dbpedia.org/ontology/director ?g_1) cardEst:~0 src:0 | ||
| filter cardEst:~5,188,789.667 | ||
| join | ||
| join-inner(nested-loop) timeLife:0.6ms | ||
| pattern (http://dbpedia.org/resource/Contact_(1992_film) http://www.w3.org/2000/01/rdf-schema#label ?title) cardEst:~1 src:0 | ||
| pattern (?g_1 http://www.w3.org/2000/01/rdf-schema#label ?name) cardEst:~20,013,903 src:0 | ||
| join compacted-occurrences:1 | ||
| join-inner(multi-empty) timeSelf:0.053ms timeLife:0.323ms | ||
| pattern (?movie http://dbpedia.org/ontology/director ?g_1) cardEst:~118,505 src:0 | ||
| pattern (?movie http://dbpedia.org/ontology/starring http://wikidata.dbpedia.org/resource/Q35332) cardEst:~0 src:0 | ||
| filter cardEst:~242,311,843,844,161 | ||
| join | ||
| join-inner(symmetric-hash) timeLife:36.548ms | ||
| pattern (?movie http://www.w3.org/2000/01/rdf-schema#label ?title) cardEst:~20,013,903 src:0 | ||
| pattern (?g_1 http://www.w3.org/2000/01/rdf-schema#label ?name) cardEst:~20,013,903 src:0 | ||
| sources: | ||
| 0: QuerySourceHypermedia(https://fragments.dbpedia.org/2016-04/en)(SkolemID:0) | ||
| ``` | ||
|
|
||
| ## ⚙️ Continuous performance tracking | ||
|
|
||
| In order to keep better track of the evolution of Comunica's performance, | ||
| we have added continuous performance tracking into our continuous integration. | ||
| For various benchmarks, we can now see the evolution of execution times across our commit history. | ||
| This allows us to easily identify which changes have a positive or negative impact on performance. | ||
|
|
||
| For considering the performance for different aspects, we have included the following benchmarks: | ||
|
|
||
| - WatDiv (in-memory) | ||
| - WatDiv (TPF) | ||
| - Berlin SPARQL Benchmark (in-memory) | ||
| - Berlin SPARQL Benchmark (TPF) | ||
| - Custom web queries: manually crafted queries to test for specific edge cases over the live Web | ||
|
|
||
| This allows us to inspect performance as follows: | ||
|
|
||
| <div class="docs-intro-img"> | ||
| <a href="https://comunica.github.io/comunica-performance-results/comunica/master/benchmarks-total/"><img src="/img/blog/2024-07-05-release_3_2/continuous-perf.png" alt="Continuous performance" style="width:100%" \></a> | ||
| </div> | ||
|
|
||
| These results can be inspected in [more close detail](https://github.com/comunica/comunica-performance-results) together with execution times per query separately. | ||
|
|
||
| ## 🏎️ Performance improvements | ||
|
|
||
| Thanks to the improvements to our physical query plan output and the continuous performance tracking, | ||
| we identified several low-hanging efforts for improving performance: | ||
|
|
||
| - [Addition of a hash-based optional join actor](https://github.com/comunica/comunica/commit/de90db0140cd10e2bfdf23c26f9eeff5e94f3ef2) | ||
| - [Tweaking constants of our internal join cost model](https://github.com/comunica/comunica/commit/50333c92ed1cf5410f172f608a213424e510986e) | ||
| - [Making optional hash and bind join only work with common variables](https://github.com/comunica/comunica/commit/df40c20e001121cd0ae9a9adf67ed221dc2966ba) | ||
|
|
||
| Besides these changes, we have many more performance-impacting changes in the pipeline for upcoming releases! | ||
|
|
||
| ## Full changelog | ||
|
|
||
| Besides this, several fixes were applied, as well as various changes and additions. | ||
| If you want to learn more about all changes, check out the [full changelog](https://github.com/comunica/comunica/blob/master/CHANGELOG.md#v320---2024-07-05). |
This file contains 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
Oops, something went wrong.