DBLE 新版本 2.18.12.0 Release

1月7日，企业级开源分布式中间件DBLE 新版本 2.18.12.0 发布，本次新版对一些可透传的复杂查询做了优化处理，不再拆分并下发而是直接透传；升级了 druid 的依赖；解决了一些由于解析器不支持的 SQL 支持度问题；修复了大量社区和专业测试团队提交的 issue，多到需要翻页。

dble 新版本 2.18.12.0 发布， 下载地址：
https://github.com/actiontech...
附件包含中文PDF文档，对应online文档地址：
https://actiontech.github.io/...

Features

• 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)

Bug-fixes

• 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为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

先好好读 Release note 原文，近期我们会有重点 issue 的修复解析文章哦，敬请期待！

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