- 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 RC4 Release Notes
On October 23, 2018, TiDB 2.1 RC4 is released. Compared with TiDB 2.1 RC3, this release has great improvement in stability, SQL optimizer, statistics information, and execution engine.
TiDB
- SQL Optimizer
- SQL Execution Engine
- Fix the precision issue of the
AVG
function #7874 - Support using the
EXPLAIN ANALYZE
statement to check the runtime statistics including the execution time and the number of returned rows of each operator during the query execution process #7925 - Fix the panic issue of the
PointGet
operator when a column of a table appears multiple times in the result set #7943 - Fix the panic issue caused by too large values in the
Limit
subclause #8002 - Fix the panic issue during the execution process of the
AddDate
/SubDate
statement in some cases #8009
- Fix the precision issue of the
- Statistics
- Fix the issue of judging the prefix of the histogram low-bound of the combined index as out of range #7856
- Fix the memory leak issue caused by statistics collecting #7873
- Fix the panic issue when the histogram is empty #7928
- Fix the issue that the histogram bound is out of range when the statistics is being uploaded #7944
- Limit the maximum length of values in the statistics sampling process #7982
- Server
- Refactor Latch to avoid misjudgment of transaction conflicts and improve the execution performance of concurrent transactions #7711
- Fix the panic issue caused by collecting slow queries in some cases #7874
- Fix the panic issue when
ESCAPED BY
is an empty string in theLOAD DATA
statement #8005 - Complete the “coprocessor error” log information #8006
- Compatibility
- Set the
Command
field of theSHOW PROCESSLIST
result toSleep
when the query is empty #7839
- Set the
- Expressions
- DDL
PD
- Fix the issue that the tombstone TiKV is not removed from Grafana #1261
- Fix the data race issue when grpc-go configures the status #1265
- Fix the issue that the PD server gets stuck caused by etcd startup failure #1267
- Fix the issue that data race might occur during leader switching #1273
- Fix the issue that extra warning logs might be output when TiKV becomes tombstone #1280
TiKV
- Optimize the RocksDB Write stall issue caused by applying snapshots #3606
- Add raftstore
tick
metrics #3657 - Upgrade RocksDB and fix the Write block issue and that the source file might be damaged by the Write operation when performing
IngestExternalFile
#3661 - Upgrade grpcio and fix the issue that “too many pings” is wrongly reported #3650
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