- Introduction
- Concepts
- Architecture
- Key Features
- Horizontal Scalability
- MySQL Compatible Syntax
- Replicate from and to MySQL
- Distributed Transactions with Strong Consistency
- Cloud Native Architecture
- Minimize ETL with HTAP
- Fault Tolerance & Recovery with Raft
- Automatic Rebalancing
- Deployment and Orchestration with Ansible, Kubernetes, Docker
- JSON Support
- Spark Integration
- Read Historical Data Without Restoring from Backup
- Fast Import and Restore of Data
- Hybrid of Column and Row Storage
- SQL Plan Management
- Open Source
- Online Schema Changes
- How-to
- Get Started
- Deploy
- Hardware Recommendations
- From Binary Tarball
- Orchestrated Deployment
- Geographic Redundancy
- Data Migration with Ansible
- Configure
- Secure
- Transport Layer Security (TLS)
- Generate Self-signed Certificates
- Monitor
- Migrate
- Maintain
- Common Ansible Operations
- Backup and Restore
- Identify Abnormal Queries
- Scale
- Upgrade
- Troubleshoot
- Reference
- SQL
- MySQL Compatibility
- SQL Language Structure
- Data Types
- Functions and Operators
- Function and Operator Reference
- Type Conversion in Expression Evaluation
- Operators
- Control Flow Functions
- String Functions
- Numeric Functions and Operators
- Date and Time Functions
- Bit Functions and Operators
- Cast Functions and Operators
- Encryption and Compression Functions
- Information Functions
- JSON Functions
- Aggregate (GROUP BY) Functions
- Window Functions
- Miscellaneous Functions
- Precision Math
- List of Expressions for Pushdown
- SQL Statements
ADD COLUMN
ADD INDEX
ADMIN
ADMIN CANCEL DDL
ADMIN CHECKSUM TABLE
ADMIN CHECK [TABLE|INDEX]
ADMIN SHOW DDL [JOBS|QUERIES]
ALTER DATABASE
ALTER TABLE
ALTER USER
ANALYZE TABLE
BEGIN
CHANGE COLUMN
COMMIT
CREATE DATABASE
CREATE INDEX
CREATE ROLE
CREATE TABLE LIKE
CREATE TABLE
CREATE USER
CREATE VIEW
DEALLOCATE
DELETE
DESC
DESCRIBE
DO
DROP COLUMN
DROP DATABASE
DROP INDEX
DROP ROLE
DROP TABLE
DROP USER
DROP VIEW
EXECUTE
EXPLAIN ANALYZE
EXPLAIN
FLUSH PRIVILEGES
FLUSH STATUS
FLUSH TABLES
GRANT <privileges>
GRANT <role>
INSERT
KILL [TIDB]
LOAD DATA
LOAD STATS
MODIFY COLUMN
PREPARE
RECOVER TABLE
RENAME INDEX
RENAME TABLE
REPLACE
REVOKE <privileges>
REVOKE <role>
ROLLBACK
SELECT
SET DEFAULT ROLE
SET [NAMES|CHARACTER SET]
SET PASSWORD
SET ROLE
SET TRANSACTION
SET [GLOBAL|SESSION] <variable>
SHOW ANALYZE STATUS
SHOW CHARACTER SET
SHOW COLLATION
SHOW [FULL] COLUMNS FROM
SHOW CREATE TABLE
SHOW CREATE USER
SHOW DATABASES
SHOW ENGINES
SHOW ERRORS
SHOW [FULL] FIELDS FROM
SHOW GRANTS
SHOW INDEXES [FROM|IN]
SHOW INDEX [FROM|IN]
SHOW KEYS [FROM|IN]
SHOW PRIVILEGES
SHOW [FULL] PROCESSSLIST
SHOW SCHEMAS
SHOW STATUS
SHOW [FULL] TABLES
SHOW TABLE REGIONS
SHOW TABLE STATUS
SHOW [GLOBAL|SESSION] VARIABLES
SHOW WARNINGS
SPLIT REGION
START TRANSACTION
TRACE
TRUNCATE
UPDATE
USE
- Constraints
- Generated Columns
- Partitioning
- Character Set
- SQL Mode
- Views
- Configuration
- Security
- Transactions
- System Databases
- Errors Codes
- Supported Client Drivers
- Garbage Collection (GC)
- Performance
- Overview
- Understanding the Query Execution Plan
- The Blocklist of Optimization Rules and Expression Pushdown
- Introduction to Statistics
- TopN and Limit Push Down
- Optimizer Hints
- Check the TiDB Cluster Status Using SQL Statements
- Execution Plan Binding
- Statement Summary Table
- Tune TiKV
- Operating System Tuning
- Column Pruning
- Key Monitoring Metrics
- Alert Rules
- Best Practices
- TiSpark
- TiKV
- TiDB Binlog
- Tools
- TiDB in Kubernetes
- FAQs
- Support
- Contribute
- Releases
- All Releases
- v3.0
- v2.1
- v2.0
- v1.0
- Glossary
Important
You are viewing the documentation of an older version of the TiDB database (TiDB v3.0).
It is recommended that you use the latest LTS version of the TiDB database.
TiDB 2.1.16 Release Notes
Release date: August 15, 2019
TiDB version: 2.1.16
TiDB Ansible version: 2.1.16
TiDB
- SQL Optimizer
- Fix the issue that row count is estimated inaccurately for the equal condition on the time column #11526
- Fix the issue that
TIDB_INLJ
Hint does not take effect or take effect on the specified table #11361 - Change the implementation of
NOT EXISTS
in a query from OUTER JOIN to ANTI JOIN to find a more optimized execution plan #11291 - Support subqueries within
SHOW
statements, allowing syntaxes such asSHOW COLUMNS FROM tbl WHERE FIELDS IN (SELECT 'a')
#11461 - Fix the issue that the
SELECT … CASE WHEN … ELSE NULL ...
query gets an incorrect result caused by the constant folding optimization #11441
- SQL Execution Engine
- Fix the issue that the
DATE_ADD
function gets a wrong result whenINTERVAL
is negative #11616 - Fix the issue that the
DATE_ADD
function might get an incorrect result because it performs type conversion wrongly when it accepts an argument of theFLOAT
,DOUBLE
, orDECIMAL
type #11628 - Fix the issue that the error message is inaccurate when CAST(JSON AS SIGNED) overflows #11562
- Fix the issue that other child nodes are not closed when one child node fails to be closed and returns an error during the process of closing Executor #11598
- Support
SPLIT TABLE
statements that return the number of Regions that are successfully split and a finished percentage rather than an error when the scheduling is not finished for Region scatter before the timeout #11487 - Make
REGEXP BINARY
function case sensitive to be compatible with MySQL #11505 - Fix the issue that
NULL
is not returned correctly because the value ofYEAR
in theDATE_ADD
/DATE_SUB
result overflows when it is smaller than 0 or larger than 65535 #11477 - Add in the slow query table a
Succ
field that indicates whether the execution succeeds #11412 - Fix the MySQL incompatibility issue caused by fetching the current timestamp multiple times when a SQL statement involves calculations of the current time (such as
CURRENT_TIMESTAMP
orNOW
) #11392 - Fix the issue that the AUTO_INCREMENT columns do not handle the FLOAT or DOUBLE type #11389
- Fix the issue that
NULL
is not returned correctly when theCONVERT_TZ
function accepts an invalid argument #11357 - Fix the issue that an error is reported by the
PARTITION BY LIST
statement. (Currently only the syntax is supported; when TiDB executes the statement, a regular table is created and a prompting message is provided) #11236 - Fix the issue that
Mod(%)
,Multiple(*)
, andMinus(-)
operations return an inconsistent0
result with that in MySQL when there are many decimal digits (such asselect 0.000 % 0.11234500000000000000
) #11353
- Fix the issue that the
- Server
- DDL
- Disallow dropping indexes on auto-increment columns to avoid incorrect results of the auto-increment columns caused by this operation #11402
- Fix the issue that the character set of the column is not correct when creating and modifying the table with different character sets and collations #11423
- Fix the issue that the column schema might get wrong when
alter table ... set default...
and another DDL statement that modifies this column are executed in parallel #11374 - Fix the issue that data fails to be backfilled when Generated Column A depends on Generated Column B and A is used to create an index #11538
- Speed up
ADMIN CHECK TABLE
operations #11538
TiKV
- Support returning an error message when the client accesses a TiKV Region that is being closed #4820
- Support reverse
raw_scan
andraw_batch_scan
interfaces #5148
Tools
- TiDB Binlog
- Add the
ignore-txn-commit-ts
configuration item in Drainer to skip executing some statements in a transaction #697 - Add the configuration item check on startup, which stops Pump and Drainer from running and returns an error message when meeting invalid configuration items #708
- Add the
node-id
configuration in Drainer to specify Drainer’s node ID #706
- Add the
- TiDB Lightning
- Fix the issue that
tikv_gc_life_time
fails to be changed back to its original value when 2 checksums are running at the same time #224
- Fix the issue that
TiDB Ansible
- Add the
log4j
configuration file in Spark #842 - Update the tispark jar package to v2.1.2 #863
- Fix the issue that the Prometheus configuration file is generated in the wrong format when TiDB Binlog uses Kafka or ZooKeeper #845
- Fix the bug that PD fails to switch the Leader when executing the
rolling_update.yml
operation #888 - Optimize the logic of rolling updating PD nodes - upgrade Followers first and then the Leader - to improve stability #895
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