Contents

1.1 million comments from Hacker News: small data full-text / analytics test

Intro

In this test we use the data collection of 1.1M Hacker News curated comments with numeric fields from https://zenodo.org/record/45901. In the modern world 1 million of documents can be considered a very small data set which, however, can be typical for many applications: blogs and news sites, online stores, job, automotive and real estate sites and so on. It’s typical for such applications to have:

  • not very long textual data in one or multiple fields
  • and a number of attributes

Data collection

The source of the data collection is https://zenodo.org/record/45901.

The record structure is:

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"properties": {
   "story_id": {"type": "integer"},
   "story_text": {"type": "text"},
   "story_author": {"type": "text", "fields": {"raw": {"type":"keyword"}}},
   "comment_id": {"type": "integer"},
   "comment_text": {"type": "text"},
   "comment_author": {"type": "text", "fields": {"raw": {"type":"keyword"}}},
   "comment_ranking": {"type": "integer"},
   "author_comment_count": {"type": "integer"},
   "story_comment_count": {"type": "integer"}
}

Databases

So far we have made this test available for 4 databases:

  • MySQL - “world’s most popular” open source OLTP database,
  • Clickhouse - a powerful OLAP database,
  • Elasticsearch - general purpose “search and analytics engine”,
  • Manticore Search - “database for search”, Elasticsearch alternative.

We’ve tried to make as little changes to database default settings as possible to not give either of them an unfair advantage:

We’ve also configured the databases to not use any internal caches:

  • Clickhouse:
    • SYSTEM DROP MARK CACHE, SYSTEM DROP UNCOMPRESSED CACHE, SYSTEM DROP COMPILED EXPRESSION CACHE after each query .
  • Elasticsearch:
    • "index.queries.cache.enabled": false in its configuration
    • /_cache/clear?request=true&query=true&fielddata=true after each query .
  • For Manticore Search in its configuration file:
    • qcache_max_bytes = 0
    • docstore_cache_size = 0
  • Operating system:
    • we do echo 3 > /proc/sys/vm/drop_caches; sync before each new query

Queries

The query set consists of both full-text and analytical (filtering, sorting, grouping, aggregating) queries:

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[
"select count(*) from hn_small",
"select count(*) from hn_small where comment_ranking=100",
"select count(*) from hn_small where comment_ranking=500",
"select count(*) from hn_small where comment_ranking > 300 and comment_ranking < 500",
"select story_author, count(*) from hn_small group by story_author order by count(*) desc limit 20",
"select story_author, avg(comment_ranking) avg from hn_small group by story_author order by avg desc limit 20",
"select comment_ranking, count(*) from hn_small group by comment_ranking order by count(*) desc limit 20",
"select comment_ranking, avg(author_comment_count) avg from hn_small group by comment_ranking order by avg desc, comment_ranking desc limit 20",
"select comment_ranking, avg(author_comment_count+story_comment_count) avg from hn_small group by comment_ranking order by avg desc, comment_ranking desc limit 20",
"select comment_ranking, avg(author_comment_count+story_comment_count) avg from hn_small where comment_ranking < 10 group by comment_ranking order by avg desc, comment_ranking desc limit 20",
{
    "manticoresearch": "select comment_ranking, avg(author_comment_count) avg from hn_small where match('google') group by comment_ranking order by avg desc, comment_ranking desc limit 20",
    "clickhouse": "select comment_ranking, avg(author_comment_count) avg from hn_small where (match(story_text, '(?i)\\Wgoogle\\W') or match(story_author,'(?i)\\Wgoogle\\W') or match(comment_text, '(?i)\\Wgoogle\\W') or match(comment_author, '(?i)\\Wgoogle\\W')) group by comment_ranking order by avg desc, comment_ranking desc limit 20",
    "elasticsearch": "select comment_ranking, avg(author_comment_count) avg from hn_small where query('google') group by comment_ranking order by avg desc, comment_ranking desc limit 20",
    "mysql": "select comment_ranking, avg(author_comment_count) avg from hn_small where match(story_text,story_author,comment_text,comment_author) against ('google') group by comment_ranking order by avg desc, comment_ranking desc limit 20"
},
{
    "manticoresearch": "select comment_ranking, avg(author_comment_count) avg from hn_small where match('google') and comment_ranking > 200 group by comment_ranking order by avg desc, comment_ranking desc limit 20",
    "clickhouse":"select comment_ranking, avg(author_comment_count) avg from hn_small where (match(story_text, '(?i)\\Wgoogle\\W') or match(story_author,'(?i)\\Wgoogle\\W') or match(comment_text, '(?i)\\Wgoogle\\W') or match(comment_author, '(?i)\\Wgoogle\\W')) and comment_ranking > 200 group by comment_ranking order by avg desc, comment_ranking desc limit 20",
    "elasticsearch":"select comment_ranking, avg(author_comment_count) avg from hn_small where query('google') and comment_ranking > 200 group by comment_ranking order by avg desc, comment_ranking desc limit 20",
    "mysql":"select comment_ranking, avg(author_comment_count) avg from hn_small where match(story_text,story_author,comment_text,comment_author) against ('google') and comment_ranking > 200 group by comment_ranking order by avg desc, comment_ranking desc limit 20"
},
{
    "manticoresearch": "select comment_ranking, avg(author_comment_count+story_comment_count) avg from hn_small where match('google') and comment_ranking > 200 group by comment_ranking order by avg desc, comment_ranking desc limit 20",
    "clickhouse": "select comment_ranking, avg(author_comment_count+story_comment_count) avg from hn_small where (match(story_text, '(?i)\\Wgoogle\\W') or match(story_author,'(?i)\\Wgoogle\\W') or match(comment_text, '(?i)\\Wgoogle\\W') or match(comment_author, '(?i)\\Wgoogle\\W')) and comment_ranking > 200 group by comment_ranking order by avg desc, comment_ranking desc limit 20",
    "elasticsearch": "select comment_ranking, avg(author_comment_count+story_comment_count) avg from hn_small where query('google') and comment_ranking > 200 group by comment_ranking order by avg desc, comment_ranking desc limit 20",
    "mysql": "select comment_ranking, avg(author_comment_count+story_comment_count) avg from hn_small where match(story_text,story_author,comment_text,comment_author) against ('google') and comment_ranking > 200 group by comment_ranking order by avg desc, comment_ranking desc limit 20"
},
{
    "manticoresearch": "select * from hn_small where match('abc') limit 20",
    "clickhouse": "select * from hn_small where (match(story_text, '(?i)\\Wabc\\W') or match(story_author,'(?i)\\Wabc\\W') or match(comment_text, '(?i)\\Wabc\\W') or match(comment_author, '(?i)\\Wabc\\W')) limit 20",
    "elasticsearch": "select * from hn_small where query('abc') limit 20",
    "mysql": "select * from hn_small where match(story_text,story_author,comment_text,comment_author) against ('google') limit 20"
},
{
    "manticoresearch": "select * from hn_small where match('abc -google') limit 20",
    "clickhouse": "select * from hn_small where (match(story_text, '(?i)\\Wabc\\W') or match(story_author,'(?i)\\Wabc\\W') or match(comment_text, '(?i)\\Wabc\\W') or match(comment_author, '(?i)\\Wabc\\W')) and not (match(story_text, '(?i)\\Wgoogle\\W') or match(story_author,'(?i)\\Wgoogle\\W') or match(comment_text, '(?i)\\Wgoogle\\W') or match(comment_author, '(?i)\\Wgoogle\\W')) limit 20",
    "elasticsearch": "select * from hn_small where query('abc !google') limit 20",
    "mysql": "select * from hn_small where match(story_text,story_author,comment_text,comment_author) against ('abc -google') limit 20"
},
{
    "manticoresearch": "select * from hn_small where match('\"elon musk\"') limit 20",
    "clickhouse": "select * from hn_small where (match(story_text, '(?i)\\Welon\\Wmusk\\W') or match(story_author,'(?i)\\Welon\\Wmusk\\W') or match(comment_text, '(?i)\\Welon\\Wmusk\\W') or match(comment_author, '(?i)\\Welon\\Wmusk\\W')) limit 20",
    "elasticsearch": "select * from hn_small where query('\\\"elon musk\\\"') limit 20",
    "mysql": "select * from hn_small where match(story_text,story_author,comment_text,comment_author) against ('\"elon musk\"') limit 20"
},
{
    "manticoresearch": "select * from hn_small where match('abc') order by comment_ranking asc limit 20",
    "clickhouse": "select * from hn_small where (match(story_text, '(?i)\\Wabc\\W') or match(story_author,'(?i)\\Wabc\\W') or match(comment_text, '(?i)\\Wabc\\W') or match(comment_author, '(?i)\\Wabc\\W')) order by comment_ranking asc limit 20",
    "elasticsearch": "select * from hn_small where query('abc') order by comment_ranking asc limit 20",
    "mysql": "select * from hn_small where match(story_text,story_author,comment_text,comment_author) against ('abc') order by comment_ranking asc limit 20"
},
{
    "manticoresearch": "select * from hn_small where match('abc') order by comment_ranking asc, story_id desc limit 20",
    "clickhouse": "select * from hn_small where (match(story_text, '(?i)\\Wabc\\W') or match(story_author,'(?i)\\Wabc\\W') or match(comment_text, '(?i)\\Wabc\\W') or match(comment_author, '(?i)\\Wabc\\W')) order by comment_ranking asc, story_id desc limit 20",
    "elasticsearch": "select * from hn_small where query('abc') order by comment_ranking asc, story_id desc limit 20",
    "mysql": "select * from hn_small where match(story_text,story_author,comment_text,comment_author) against ('abc') order by comment_ranking asc, story_id desc limit 20"
},
{
    "manticoresearch": "select count(*) from hn_small where match('google') and comment_ranking > 200",
    "clickhouse": "select count(*) from hn_small where (match(story_text, '(?i)\\Wgoogle\\W') or match(story_author,'(?i)\\Wgoogle\\W') or match(comment_text, '(?i)\\Wgoogle\\W') or match(comment_author, '(?i)\\Wgoogle\\W')) and comment_ranking > 200",
    "elasticsearch": "select count(*) from hn_small where query('google') and comment_ranking > 200",
    "mysql": "select count(*) from hn_small where match(story_text,story_author,comment_text,comment_author) against ('google') and comment_ranking > 200"
},
{
    "manticoresearch": "select story_id from hn_small where match('me') order by comment_ranking asc limit 20",
    "clickhouse": "select story_id from hn_small where (match(story_text, '(?i)\\Wme\\W') or match(story_author,'(?i)\\Wme\\W') or match(comment_text, '(?i)\\Wme\\W') or match(comment_author, '(?i)\\Wme\\W')) order by comment_ranking asc limit 20",
    "elasticsearch": "select story_id from hn_small where query('me') order by comment_ranking asc limit 20",
    "mysql": "select story_id from hn_small where match(story_text,story_author,comment_text,comment_author) against ('me') order by comment_ranking asc limit 20"
},
{
    "manticoresearch": "select story_id, comment_id, comment_ranking, author_comment_count, story_comment_count, story_author, comment_author from hn_small where match('abc') limit 20",
    "clickhouse": "select story_id, comment_id, comment_ranking, author_comment_count, story_comment_count, story_author, comment_author from hn_small where (match(story_text, '(?i)\\Wabc\\W') or match(story_author,'(?i)\\Wabc\\W') or match(comment_text, '(?i)\\Wabc\\W') or match(comment_author, '(?i)\\Wabc\\W')) limit 20",
    "elasticsearch": "select story_id, comment_id, comment_ranking, author_comment_count, story_comment_count, story_author, comment_author from hn_small where query('abc') limit 20",
    "mysql": "select story_id, comment_id, comment_ranking, author_comment_count, story_comment_count, story_author, comment_author from hn_small where match(story_text,story_author,comment_text,comment_author) against ('abc') limit 20"
},
"select * from hn_small order by comment_ranking asc limit 20",
"select * from hn_small order by comment_ranking desc limit 20",
"select * from hn_small order by comment_ranking asc, story_id asc limit 20",
"select comment_ranking from hn_small order by comment_ranking asc limit 20",
"select comment_ranking, story_text from hn_small order by comment_ranking asc limit 20",
"select count(*) from hn_small where comment_ranking in (100,200)",
"select story_id from hn_small order by comment_ranking asc, author_comment_count asc, story_comment_count asc, comment_id asc limit 20"
]

Results

You can find all the results on the results page by selecting “Test: hn_small”.

Remember that the only high quality metric is “Fast avg” since it guarantees low coefficient of variation and high queries count conducted for each query. The other 2 (“Fastest” and “Slowest”) are provided with no guarantee since:

  • Slowest - is a single attempt result, in most cases the very first coldest query. Even though we purge OS cache before each cold query it can’t be considered stable. So it can be used for informational purposes and is greyed out in the below summary.
  • Fastest - just the very fastest result, it should be in most cases similar to the “Fast avg” metric, but can be more volatile from run to run.

Remember the tests including the results are 100% transparent as well as everything in this project, so:

Unlike other less transparent and less objective benchmarks we are not making any conclusions, we are just leaving screenshots of the results here:

4 competitors at once

/test-hn-small/4.png

MySQL vs Clickhouse

/test-hn-small/my_ch.png

MySQL vs Elasitcsearch

/test-hn-small/my_es.png

/test-hn-small/my_ms.png

Clickhouse vs Elasticsearch

/test-hn-small/ch_es.png

Manticore Search vs Elasticsearch

/test-hn-small/ms_es.png

Manticore Search vs Clickhouse

/test-hn-small/ms_ch.png

Disclaimer

The author of this test and the test framework is a member of Manticore Search core team and the test was initially made to compare Manticore Search with Elasticsearch, but as shown above and can be verified in the open source code and by running the same test yourself Manticore Search wasn’t given any unfair advantage, so the test can be considered unprejudiced. However, if something is missing or wrong (i.e. non-objective) in the test feel free to make a pull request or an issue on Github . Your take is appreciated! Thank you for spending your time reading this!