Release 2.19.07.0

We have released a new version 2.19.07.0.
Firstly, we must thanks to the following people for their contributions to our community：
@kaikai2000, @Lordess, @ssxlulu, @canying8020, @newskyddm, @wbshen

Release Notes:

Features:

• [#1263] Add command release @@reload_metadata and show @@reload_status to make reload observable. For more details, click here.
• [#1264] Support more ways for exporting and importing data. For more details, click here.
• [#1332] Support create FUNCTION just like create PROCEDURE.
• [#1356] Support COM_CHANGE_USER and COM_RESET_CONNECTION. For more details, click here.
• [#1326] Support COM_SET_OPTION. For more details, click here.
• [#759] Add manager command:show @@user,show @@user.privilege,modify manager command:show @@Datasource,show @@datasource.synstatus,show @@datasource.syndetail where name=?,show @@datasource.cluster. For more details, click here.
• [#1340] Refactor heartbeat logic. For more details, click here.
• [#1342] Modify column name that contains connetciton id in manager command and log. For more details, click here.
• [#1266] Provious gc log can't be overried when user restarts dble.
• [#877] Support statement SAVEPOINT, thanks @wbshen report this issue

Bug-fixes:

• [#1383] reload @@config_all failed may lead to connections for new added datahost in config leaking.
• [#1184] Global sequences generated by distributed timestamps may have duplicate values.
• [#1212] Restart dble may fail in zk cluster.
• [#1286] Parameter sqlExecuteTimeout is invalid.
• [#1229] When there are lowercase and uppercase in the field in differernt table, Join returns null, missing result set, thanks @kaikai2000 report the bug.
• [#1368] encrypt.sh always return true whether the encryption failed or not, thanks @Lordess report and fix the bug.
• [#1327] Complex select columns may lead "can not find error" in join query.
• [#1351] No-sharding table's sub-query with union should be treated as simple query.
• [#1241] Report error when '-' in the name of schema.
• [#1261] MultiSQLJob is not thread safe & countDownShardTable not correct, may cause reload hang.
• [#1322] Check different dataNodes with same dataHost and same database.
• [#1300] Incorrect comment in initSource method of class PhysicalDBPool, thanks @ssxlulu report and fix the bug.
• [#1306] Got error while executing sql"select a.* from sharding_4_t1 a ,schema2.sharding_4_t2 b where a.id = b.id and b.name = '1';"
• [#1301] dble will got NPE error while executing the sql "select t1.id from DbTest.Test_Table T1 left join Test t2 on t1.id=t2.Id;"
• [#1280] Views created in the current database cannot be associated with tables in another database, and database prefixes cannot be added, thanks @canying8020 report the bug.
• [#1250] Load data incorrect with default fields terminate when tab's space exists in file
• [#1288] For global table, got error while execute "select a.id,b.* from schema2.test2 a inner join test1 b on a.id+1 =b.id+2;"
• [#1251] Explain the child table in the er table, the statement is actually executed
• [#1255] Error when execute "select a.id,b.* from test2 a inner join test1 b on a.id =b.id+1;", thanks @newskyddm report the bug.
• [#1256] Error when execute "select test1.id,test1.id+1 as rpda_0 from test1 order by rpda_0 ASC", thanks @newskyddm report the bug.
• [#960] For no-sharding table, got wrong result while executing sql "SELECT CURRENT_USER() union select id from test1"
• [#1268] For global table, got error while executing "select count(*) from (select O_CUSTKEY,count(O_CUSTKEY) as counts from test1 group by O_CUSTKEY) as a where counts<10 group by counts;"

Breaking backward compatibility:

• [#759] show @@Datasource,show @@datasource.synstatus,show @@datasource.syndetail where name=?,show @@datasource.cluster add DATAHOST column
• [#1272] Remove the property useOldMetaInit in server.xml.
• [#1291] Change the default charset from utf8 to utf8mb4.
• [#1260] Refactoring attribute 'version' in xml config. For more details, click here.