Fix onReplayAppendCmd. Check whether there exists active block before load data.

Approved by: @XuPeng-SH

Approved by: @XuPeng-SH

* Fix the bug that block&index file reference count is not released

* Remove redundant Unref

* Fix the bug that FlushIndex has no unref

fix #4023

hakeeper: do not remove replica if it is in LogShardInfo.Replica despite it's epoch is small. (#4010)

delete CHINESE old tech design, MatrixCube and distributed settings doc, translate mysql compatibility doc to CN (#4014)

* remove useless code in bitmap

* Modify the comment format

* refactor toarray of bitmap

Co-authored-by: Yingfeng <yingfeng.zhang@gmail.com>

* Add aggregate framework

* Add distinct aggregate function

* Add example aggregation function count

* Add some comment of agg

* Fix bug of count

* Add handler of count(*) of count

Co-authored-by: maomao <77312370+sukki37@users.noreply.github.com>

* fix static check error

* fix static check error

* fix static check error

* Update ci.yml
Co-authored-by: lni <nilei81@gmail.com>

fill null pos is an noop.   It's only purpuse is to hide
bugs and that is a very bad thing.

* add test for expired op && fix memory error

* modify bootstrap commands

* (tae): update deletes

* (tae): update mutable index to revert changes

* (tae): fix static code check

* init prepare support in plan

* bug fix and add ut

* refactor some variable's name

* support more statement in prepare

* merge main and rebuild pb and mysql_sql.go

* use optimizer result in prepare plan

* add testcase in frontend module

* add testcase in frontend module

* Add new bitmap

* Fix the bug of bitmap's marshal

Minor update to boolean ops.  I cannot say I fully understand
our boolop, but better not to touch at this moment.