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TiDB 2.1.8 Release Notes
Release date: April 12, 2019
TiDB version: 2.1.8
TiDB Ansible version: 2.1.8
TiDB
- Fix the issue that the processing logic of
GROUP_CONCAT
function is incompatible with MySQL when there is a NULL-valued parameter #9930 - Fix the equality check issue of decimal values in the
Distinct
mode #9931 - Fix the collation compatibility issue of the date, datetime, and timestamp types for the
SHOW FULL COLUMNS
statement - Fix the issue that the row count estimation is inaccurate when the filtering condition contains correlated columns #9937
- Fix the compatibility issue between the
DATE_ADD
andDATE_SUB
functions - Support the
%H
format for theSTR_TO_DATE
function to improve compatibility #9964 - Fix the issue that the result is wrong when the
GROUP_CONCAT
function groups by a unique index #9969 - Return a warning when the Optimizer Hints contains an unmatched table name #9970
- Unify the log format to facilitate collecting logs using tools for analysis Unified Log Format
- Fix the issue that a lot of NULL values cause inaccurate statistics estimation #9979
- Fix the issue that an error is reported when the default value of the TIMESTAMP type is the boundary value #9987
- Validate the value of
time_zone
#10000 - Support the
2019.01.01
time format #10001 - Fix the issue that the row count estimation is displayed incorrectly in the result returned by the
EXPLAIN
statement in some cases #10044 - Fix the issue that
KILL TIDB [session id]
cannot instantly stop the execution of a statement in some cases #9976 - Fix the predicate pushdown issue of constant filtering conditions in some cases #10049
- Fix the issue that a read-only statement is not processed correctly in some cases #10048
PD
- Fix the issue that
regionScatterer
might generate an invalidOperatorStep
#1482 - Fix the issue that a hot store makes incorrect statistics of keys #1487
- Fix the too short timeout issue of the
MergeRegion
operator #1495 - Add elapsed time metrics of the PD server handling TSO requests #1502
TiKV
- Fix the issue of wrong statistics of the read traffic #4441
- Fix the raftstore performance issue when too many Regions exist #4484
- Do not ingest files when the number of level 0 SST files exceeds
level_zero_slowdown_writes_trigger/2
#4464
Tools
- Optimize the order of importing tables for Lightning to reduce the effects of large tables executing
Checksum
andAnalyze
on the cluster during the importing process and improve the success rate ofChecksum
andAnalyze
#156 - Improve the encoding SQL performance by 50% for Lightning by directly parsing the data source file content to
types.Datum
of TiDB to avoid additional parsing working of the KV encoder #145 - Add the
storage.sync-log
configuration item in TiDB Binlog Pump to support flushing disks of the local storage asynchronously in Pump #529 - Support traffic compression of communication between TiDB Binlog Pump and Drainer #530
- Add the
syncer.sql-mode
configuration item in TiDB Binlog Drainer to support using differentsql-mode
s to parse DDL queries #513 - Add the
syncer.ignore-table
configuration item in TiDB Binlog Drainer to support filtering tables not to be replicated #526
TiDB Ansible
- Modify the version limit for the operating system and only support CentOS 7.0 or later and Red Hat 7.0 or later #734
- Add the feature of checking whether
epollexclusive
is supported in every OS #728 - Add the version limit for rolling update to prohibit upgrading a version of 2.0.1 or earlier to a version of 2.1 or later #728
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