Release 2.18.07.2

Features:

• Optimize testConn
• Add log for reload
• Rewrite [reload @@config_all|reload @@config_all] to avoid reading config files twice (#552 #590)

Bug-fixes:

• Timestamp data type of response for query from manager port is wrong #569
• Table [table_number] name was changed by Druid #576
• Error when view contains a statement which likeselect table1.name,table2.name as t_name #345
• Send DDL query after maxConn was reached, then DDL lock in memory is left #583
• When DDL contains Chinese, and the environment is not UTF-8 and deploy in Ucore Cluster,the DDL may hang
• Small table inner join big table may cause connection leak #588
• Select item contains an aggregate function with alias which is same to origin column and having clause contains the same aggregate function, the query will report error #599
• Join SQL return wrong result when join column contains null value #600

Breaking backward compatibility:

• Delay detection will no longer dependent on switchType =2

Different from MySQL

• Set all message in OK packet to null #549