tidb-server v2.1.0-rc.5

SQL Optimizer

• Fix the issue that IndexReader reads the wrong handle in some cases #8132
• Fix the issue occurred while the IndexScan Prepared statement uses Plan Cache #8055
• Fix the issue that the result of the Union statement is unstable #8165

SQL Execution Engine

• Improve the performance of TiDB on inserting or updating wide tables #8024
• Support the unsigned int flag in the Truncate built-in function #8068
• Fix the error occurred while converting JSON data to the decimal type #8109
• Fix the error occurred when you Update the float type #8170

Statistics

• Fix the incorrect statistics issue during point queries in some cases #8035
• Fix the selectivity estimation of statistics for primary key in some cases #8149
• Fix the issue that the statistics of deleted tables are not cleared up for a long period of time #8182

Server

• Improve the readability of logs and make logs better
  • #8063
  • #8053
  • #8224
• Fix the error occurred when obtaining the table data of infoschema.profiling #8096
• Replace the unix socket with the pumps client to write binlogs #8098
• Add the threshold value for the tidb_slow_log_threshold environment variable, which dynamically sets the slow log #8094
• Add the original length of a SQL statement truncated while the tidb_query_log_max_len environment variable dynamically sets logs 8200
• Add the tidb_opt_write_row_id environment variable to control whether to allow writing _tidb_rowid #8218
• Add an upper bound to the Scan command of ticlient, to avoid overbound scan #8081, #8247

DDL

• Fix the issue that executing DDL statements in transactions encounters an error in some cases #8056
• Fix the issue that executing truncate table in partition tables does not take effect #8103
• Fix the issue that the DDL operation does not roll back correctly after being cancelled in some cases #8057
• Add the admin show next_row_id command to return the next available row ID #8268