Azat Khuzhin
064f901ea8
Add ability to preallocate hashtables for hashed/sparsehashed dictionaries
...
preallocation can be used only when we know number of rows, and for this
we need:
- source clickhouse
- no filtering (i.e. lack of <where>), since filtering can filter
too much rows and eventually it may allocate memory that will
never be used.
For sparse_hash the difference is quite significant, preallocated
sparse_hash hashtable allocates ~33% faster (7.5 seconds vs 5 seconds
for insert, and the difference is more significant for higher number of
elements):
$ ninja bench-sparse_hash-run
[1/1] cd /src/ch/hashtable-bench/.cmake && ...ch/hashtable-bench/.cmake/bench-sparse_hash
sparse_hash/insert: 7.574 <!--
sparse_hash/find : 2.14426
sparse_hash/maxrss: 174MiB
sparse_hash/time: 9710.51 msec (user+sys)
$ time ninja bench-sparse_hash-preallocate-run
[1/1] cd /src/ch/hashtable-bench/.cmake && ...-bench/.cmake/bench-sparse_hash-preallocate
sparse_hash/insert: 5.0522 <!--
sparse_hash/find : 2.14024
sparse_hash/maxrss: 174MiB
sparse_hash/time: 7192.06 msec (user+sys)
P.S. the difference for sparse_hashed dictionary with 4e9 elements
(uint64, uint16) is ~18% (4975.905 vs 4103.569 sec)
v2: do not reallocate the dictionary from the progress callback
Since this will access hashtable in parallel.
v3: drop PREALLOCATE() and do this only for source=clickhouse and empty
<where>
2020-10-09 22:28:14 +03:00
Vladimir Golovchenko
21bc856d61
Improved the description of connecting to MS SQL Server by ODBC.
2020-09-15 11:26:57 -07:00
Dmitrii Raev
2a575fd5c8
Update external-dicts-dict-lifetime.md ( #12657 )
...
duplicated line
2020-07-22 11:26:04 +03:00
Ivan Blinkov
258d2fd499
[docs] split various kinds of CREATE queries into separate articles ( #12328 )
...
* normalize
* split & adjust links
* re-normalize
* adjust ru links
* adjust ja/tr links
* partially apply e0d19d2aea
2020-07-09 18:10:35 +03:00
Nikita Mikhaylov
e55577ba65
Merge branch 'nikvas0/ssd_dict' of git://github.com/nikvas0/ClickHouse into merging-ssh-cache
2020-06-24 16:45:18 +03:00
Ivan Blinkov
652882ef4e
[docs] reorganized F.A.Q.
2020-06-22 16:35:41 +03:00
Ivan Blinkov
7170f3c534
[docs] split aggregate function and system table references ( #11742 )
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* prefer relative links from root
* wip
* split aggregate function reference
* split system tables
2020-06-18 11:24:31 +03:00
Alexander Tokmakov
e67837bc4a
cleenup
2020-06-04 00:11:17 +03:00
Nikita Vasilev
e7324ec4d7
docs
2020-05-23 13:41:27 +03:00
Alexander Tokmakov
175b7aedf3
Merge branch 'master' into merging_external_source_cassandra
2020-05-19 05:21:27 +03:00
Артем Стрельцов
6b12cfb8e4
documentation added
2020-05-13 19:05:05 +03:00
Ilya Yatsishin
1d281ec032
Merge pull request #10652 from BayoNet/docs/CLICKHOUSEDOCS-623-dicts
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DOCS-623: Updated introduction to external dictionaries
2020-05-08 09:35:13 +03:00
Artem Streltsov
5220d9a4db
small docs edit ( #10731 )
...
Co-authored-by: Артем Стрельцов <artemstreltsov@Air-2.local>
2020-05-07 23:00:30 +03:00
alexey-milovidov
eeac7aa313
Merge pull request #10622 from kekekekule/layout_direct
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Add direct layout for dictionaries
2020-05-07 01:05:29 +03:00
BayoNet
dba72d73fe
DOCS-624: Fixing links to nowhere ( #10675 )
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* enbaskakova-DOCSUP-652 (#101 )
* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"
* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"
* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"
* Update docs/en/sql_reference/aggregate_functions/combinators.md
Co-Authored-By: BayoNet <da-daos@yandex.ru>
* Update docs/en/sql_reference/aggregate_functions/combinators.md
Co-Authored-By: BayoNet <da-daos@yandex.ru>
* Update docs/en/sql_reference/aggregate_functions/combinators.md
Co-Authored-By: BayoNet <da-daos@yandex.ru>
* Update docs/en/sql_reference/aggregate_functions/combinators.md
Co-Authored-By: BayoNet <da-daos@yandex.ru>
* Update docs/en/sql_reference/aggregate_functions/combinators.md
Co-Authored-By: BayoNet <da-daos@yandex.ru>
* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"
* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"
* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"
Co-authored-by: elenbaskakova <elenbaskakova@yandex-team.ru>
Co-authored-by: BayoNet <da-daos@yandex.ru>
* Revert "enbaskakova-DOCSUP-652 (#101 )" (#107 )
This reverts commit 639fee7610
2020-05-06 09:13:29 +03:00
Sergei Shtykov
efa040050c
CLICKHOUSEDOCS-623: Typo fix.
2020-05-04 14:42:34 +03:00
Sergei Shtykov
37d7bedba2
CLICKHOUSEDOCS-623: Updated introduction to external dictionaries.
2020-05-04 14:39:43 +03:00
Nikolay Degterinsky
a3e557a5d2
documentation is added & added 'direct' layout into integragion test
2020-05-03 15:55:22 +03:00
Ivan Blinkov
d91c97d15d
[docs] replace underscores with hyphens ( #10606 )
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* Replace underscores with hyphens
* remove temporary code
* fix style check
* fix collapse
2020-04-30 21:19:18 +03:00
