Prototype lighweight mutation for mergetree

[zhangjmruc]

Changelog category (leave one):

• New Feature

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):
prototype of implementation of lightweight delete and update for merge tree engine.

Description:
This pull request does similar work as #32774.

[antip00]

it does not work for me

create table au(id Int64, x Int64) engine=MergeTree order by id

insert into au select number % 10, number % 100 from numbers(10000)

alter table au delete where id>50

if you use alter delete with mutation_sync=1 or mutation_sync=2 then it breaks on alter delete

select count(*) from au

it is stuck for a few mins
then exeption
Exception on client:
Code: 32. DB::Exception: Attempt to read after eof: while receiving packet from localhost:9000. (ATTEMPT_TO_READ_AFTER_EOF)

Connecting to localhost:9000 as user default.
Code: 210. DB::NetException: Connection reset by peer, while reading from socket (127.0.0.1:9000). (NETWORK_ERROR)

[zhangjmruc]

I recreated your issue. Will check further and fix it.
Fixed this issue during rebase.

alter table au delete where id>50

it does not work for me

create table au(id Int64, x Int64) engine=MergeTree order by id

insert into au select number % 10, number % 100 from numbers(10000)

alter table au delete where id>50

if you use alter delete with mutation_sync=1 or mutation_sync=2 then it breaks on alter delete

select count(*) from au

it is stuck for a few mins then exeption Exception on client: Code: 32. DB::Exception: Attempt to read after eof: while receiving packet from localhost:9000. (ATTEMPT_TO_READ_AFTER_EOF)

Connecting to localhost:9000 as user default. Code: 210. DB::NetException: Connection reset by peer, while reading from socket (127.0.0.1:9000). (NETWORK_ERROR)

[zhangjmruc]

@nikitamikhaylov The failing check is not related to this request. How to proceed?

[zhangjmruc]

@davenger Are you reviewing this pull request? Please let me know if you have any comment. Thank you for your time

[zhangjmruc]

Will split into lightweight delete and lightweight update.

[vkrot-innio]

@zhangjmruc , is there any ongoing progress / plans in lightweight deletes implementation? or is it abandoned?

[zhangjmruc]

@vkrot-innio I'm working on the implementation of lightweight delete. Will use this new pull request #37893.
It's more complex for the select query when I tried to add a virtual column _delete.