1月7日，企業級開源分散式中介軟體DBLE 新版本 2.18.12.0 釋出，本次新版對一些可透傳的複雜查詢做了優化處理，不再拆分並下發而是直接透傳；升級了 druid 的依賴；解決了一些由於解析器不支援的 SQL 支援度問題；修復了大量社群和專業測試團隊提交的 issue，多到需要翻頁。

dble 新版本 2.18.12.0 釋出， 下載地址：

https://github.com/actiontech/dble/releases  

附件包含中文PDF文件，對應online文件地址：

https://actiontech.github.io/dble-docs-cn/ 

• Support MySQL Protocol::AuthSwitchRequest #819

• Optimize Query Plan: Some queries can be sent to one datanode in fact, no need to rewrite and push down.#752

• Support DDL: create table tbl_name { LIKE old_tbl_name | (LIKE old_tbl_name) } 

  #757

• Upgrade Druid from 1.0.31 to 1.1.10 #749

• The log of config error can't tell which property make it #905

• Add manager command of show @@Alert (for bussiness support)

• When useJoinStrategy, join with limit and use nest loop in fact, the Explain result lost rows

   #777

• The error log is too simple when dble can not connection to backend connection #765

• Complex query got syntax error which caused by string in "group by" #779

• Query statements with 2 subqueries can cause thread safty problem #917

• Global table union with none global table get unexpect unreadable error:ERROR 1105 (HY000): Index: 2, Size: 2 #860

• "order by" can't work fine in sharding table #889

• Unreasonable error message when explain help#899

• Close the session while doing DDL, the DDL lock may not be removed #797

• show index from global_table/*abc*/ may be route to default datanode #892

• Reload return detail when Error "other session doing DDL" #900

• “unexpected packet” log in dble.log when execute subquery in dble and commit #897

• COM_STMT_SEND_LONG_DATA handle error #869

• Inappropriate hints when explain view #837

• Can't support Escape character in prepare statement：prepare stmt from 'insert into aly_test values(111,111,'test中id為1',111)'; #872

• management cmd "reload @@query_cf" does not work #875

• Can not reflect view under view list after creating the view correctly #825

• For .net connector 6.8.8, can't connect to dble with the port 9066 #878

• It will show wrong table schema and duplicate table names on the table list after we click the 'design table' #824

• Dbeaver gui can't display the table list correctly #829

• View will not reflect on the schema list and can't dispay the right content after executing the sql 'show create view view_tt;' #827

• Meta data check should ignore AUTO_INCREMENT difference #867

• MySQL Workbench8.0 does not show the global table 'test' #842

• Rollback with hint will send to schema default datanode #533

• dble parses empty column for int to NULL while mysql parses to 0 in [load data ...] query #768

• System parameter maxCon is invalid after a connection failure #838

• Error when querying data from mysql table named keys #798

• Error while using the keyword as the view name in the "show create view" statement #856

• Insert statements involving multiple nodes will be stored in the slow log #807

• Union syntax, select a column twice got error #790

• Add order by for the entire UNION result will get wrong result #791

• [select * from sharding_two_node where id is null] gets lost connection ... #800

• Without default database explain failed even referring database at table quote #813

• Error when insert contains scheam name in the no_sharding table #836

• [select count(distinct col1,col2) from ... group by col2] get different result from mysql Aggregate function #845

• Error when the global table is joined with the non-split table and the two tables have a shared node #848

• [select sec_to_time(sum(time_to_sec(t))) from a_manager] get error result Aggregate function #814

• [select * from aly_test where id =ALL(select 1);] success but explain failed #796

• Function group_concat ([order by ... desc...]), 'order by' and 'desc' do not work as same as mysql #820

• Incorrect result on select contains stddev() #844

• Some datanodes cannot be connectted when macCon <= the number of datanode#822

• Error when insert into sharding column null while it has default null value #831

• Insert into sharding column(type timestamp) null while it has default not null value will violate sharding expectation #815

• Error,when the join clause contains STR_TO_DATE() and conditional_expr is a non-split column #817

• Parses empty line different with mysql in [load data ...] query #769

• Incorrect result on show @@connection.sql.EXECUTE_TIME when the execution time of query<1ms #785

• writeHost in schema.xml should support "weight" #793

• NPE when the data of the insert exceeds the character length in the case of opening the slow log #783

• [load data ...] without default database got npe #776

• [create table if not exists test_table(id int)] got error if table already exists #784

• Navicat Premium 12 can not connect dble driver #633

• Parser Error when index contains comment #495

• [check full @@metadata] gives global table metadata right while the table is not exist in some datanode #786

• Druid can't discriminate between "set session tx_variables,xxx" and "set tx_variables,xxx" #316

• SQL parser can not tell the difference of ~id =1 and ~(id =1)#302

• Error when select syntax contains two ignore key(key_name)#413

• Error when create statement contains the option of "algorithm" #258

• Error on index_hint_list which contains multiple index hints #272

• [management-command]JDBC5.1.31 can not connect manager port #680

• Escape character has been lost #295

• [lock table ... write] cannot be parsed by druid #744

• When lower_case_table_names =1, error caused by schema_name case sensitive #771

• Query in dble returns "0" while the same query in mysql returns "null" #760

先好好讀 Release note 原文，近期我們會有重點 issue 的修復解析文章哦，敬請期待！