- 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
- Use BR (recommended)
- Identify Abnormal Queries
- Scale
- Upgrade
- Troubleshoot
- Reference
- SQL
- MySQL Compatibility
- SQL Language Structure
- Attributes
- 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 INSTANCE
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
- Follower Read
- 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
- TiFlash
- TiDB Binlog
- Tools
- Overview
- Use Cases
- Download
- TiDB Operator
- Table Filter
- Backup & Restore (BR)
- Mydumper
- Syncer
- Loader
- Data Migration
- TiDB Lightning
- sync-diff-inspector
- PD Control
- PD Recover
- TiKV Control
- TiDB Control
- TiDB in Kubernetes
- FAQs
- Support
- Contribute
- Releases
- All Releases
- v3.1
- v3.0
- v2.1
- v2.0
- v1.0
- Glossary
Important
You are viewing the documentation of an older version of the TiDB database (TiDB v3.1).
It is recommended that you use the latest LTS version of the TiDB database.
TiDB 2.1.5 Release Notes
On February 28, 2019, TiDB 2.1.5 is released. The corresponding TiDB Ansible 2.1.5 is also released. Compared with TiDB 2.1.4, this release has greatly improved the stability, the SQL optimizer, statistics, and the execution engine.
TiDB
- SQL Optimizer/Executor
- Make
SHOW CREATE TABLE
do not print the column charset information when the charset information of a column is the same with that of a table, to improve the compatibility ofSHOW CREATE TABLE
with MySQL #9306 - Fix the panic or the wrong result of the
Sort
operator in some cases by extractingScalarFunc
fromSort
to aProjection
operator for computing to simplify the computing logic ofSort
#9319 - Remove the sorting field with constant values in the
Sort
operator #9335, #9440 - Fix the data overflow issue when inserting data into an unsigned integer column #9339
- Set
cast_as_binary
toNULL
when the length of the target binary exceedsmax_allowed_packet
#9349 - Optimize the constant folding process of
IF
andIFNULL
#9351 - Optimize the index selection of TiDB using skyline pruning to improve the stability of simple queries #9356
- Support computing the selectivity of the
DNF
expression #9405 - Fix the wrong SQL query result of
!=ANY()
and=ALL()
in some cases #9403 - Fix the panic or the wrong result when the Join Key types of two tables on which the
Merge Join
operation is performed are different #9438 - Fix the issue that the result of the
RAND()
function is not compatible with MySQL #9446 - Refactor the logic of
Semi Join
processingNULL
and the empty result set to get the correct result and improve the compatibility with MySQL #9449
- Make
- Server
- Add the
tidb_constraint_check_in_place
system variable to check the data uniqueness constraint when executing theINSERT
statement #9401 - Fix the issue that the value of the
tidb_force_priority
system variable is different from that set in the configuration file #9347 - Add the
current_db
field in general logs to print the name of the currently used database #9346 - Add an HTTP API of obtaining the table information with the table ID #9408
- Fix the issue that
LOAD DATA
loads incorrect data in some cases #9414 - Fix the issue that it takes a long time to build a connection between the MySQL client and TiDB in some cases #9451
- Add the
- DDL
- Fix some issues when canceling the
DROP COLUMN
operation #9352 - Fix some issues when canceling the
DROP
orADD
partitioned table operation #9376 - Fix the issue that
ADMIN CHECK TABLE
mistakenly reports the data index inconsistency in some cases #9399 - Fix the time zone issue of the
TIMESTAMP
default value #9108
- Fix some issues when canceling the
PD
- Provide the
exclude_tombstone_stores
option in theGetAllStores
interface to remove the Tombstone store from the returned result #1444
TiKV
- Fix the issue that Importer fails to import data in some cases #4223
- Fix the
KeyNotInRegion
error in some cases #4125 - Fix the panic issue caused by Region merge in some cases #4235
- Add the detailed
StoreNotMatch
error message #3885
Tools
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