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ADD COLUMN
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ADMIN
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BACKUP
BEGIN
CHANGE COLUMN
COMMIT
CHANGE DRAINER
CHANGE PUMP
CREATE [GLOBAL|SESSION] BINDING
CREATE DATABASE
CREATE INDEX
CREATE ROLE
CREATE SEQUENCE
CREATE TABLE LIKE
CREATE TABLE
CREATE USER
CREATE VIEW
DEALLOCATE
DELETE
DESC
DESCRIBE
DO
DROP [GLOBAL|SESSION] BINDING
DROP COLUMN
DROP DATABASE
DROP INDEX
DROP ROLE
DROP SEQUENCE
DROP STATS
DROP TABLE
DROP USER
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EXECUTE
EXPLAIN ANALYZE
EXPLAIN
FLASHBACK TABLE
FLUSH PRIVILEGES
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FLUSH TABLES
GRANT <privileges>
GRANT <role>
INSERT
KILL [TIDB]
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PREPARE
RECOVER TABLE
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REVOKE <privileges>
REVOKE <role>
ROLLBACK
SELECT
SET DEFAULT ROLE
SET [NAMES|CHARACTER SET]
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SET [GLOBAL|SESSION] <variable>
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mysql
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TiDB 4.0 RC Release Notes
Release date: April 8, 2020
TiDB version: 4.0.0-rc
TiUP version: 0.0.3
Warning:
Some known issues are found in this version, and these issues are fixed in new versions. It is recommended that you use the latest 4.0.x version.
Compatibility Changes
TiDB
- Refuse to get started instead of returning an alert log when the tidb-server status port is occupied #15177
TiKV
- Support the
pipelined
feature in pessimistic transactions, which improves the TPC-C performance by 20%. The risk is that the transaction commit might fail because of lock failure during the execution #6984 - Enable the
unify-read-pool
configuration item in new clusters by default and use the previous setting of this item in old clusters #7059
- Support the
Tools
TiDB Binlog
- Add the configuration item for verifying Common Name #934
Important Bug Fixes
TiDB
- Fix the issue that replication between the upstream and downstream might go wrong when the DDL job is executed using the
PREPARE
statement because of the incorrect job query in the internal records #15435 - Fix the issue of incorrect subquery result in the
Read Commited
isolation level #15471 - Fix the issue of incorrect results caused by the Inline Projection optimization #15411
- Fix the issue that the SQL Hint
INL_MERGE_JOIN
is executed incorrectly in some cases #15515 - Fix the issue that columns with the
AutoRandom
attribute are rebased when the negative number is explicitly written to these columns #15397
- Fix the issue that replication between the upstream and downstream might go wrong when the DDL job is executed using the
New Features
TiDB
- Add the case-sensitive collation so that users can enable
utf8mb4_general_ci
andutf8_general_ci
in a new cluster #33 - Enhance the
RECOVER TABLE
syntax to support recovering truncated tables #15398 - Refuse to get started instead of returning an alert log when the the tidb-server status port is occupied #15177
- Optimize the write performance of using a sequence as the default column values #15216
- Add the
DDLJobs
system table to query the details of DDL jobs #14837 - Optimize the
aggFuncSum
performance #14887 - Optimize the output of
EXPLAIN
#15507
- Add the case-sensitive collation so that users can enable
TiKV
- Support the
pipelined
feature in pessimistic transactions, which improves the TPC-C performance by 20%. The risk is that the transaction commit might fail because of lock failure during the execution #6984 - Support TLS in the HTTP port #5393
- Enable the
unify-read-pool
configuration item in new clusters by default and use the previous setting of this item in old clusters #7059
- Support the
PD
- Support getting the default PD configuration information through the HTTP API #2258
Tools
Bug Fixes
TiDB
- Fix the issue that replication between the upstream and downstream might go wrong when the DDL job is executed using the
PREPARE
statement because of the incorrect job query in the internal records #15435 - Fix the issue of incorrect subquery result in the
Read Commited
isolation level #15471 - Fix the issue of possible wrong behavior when using
INSERT ... VALUES
to specify theBIT(N)
data type #15350 - Fix the issue that the DDL Job internal retry does not fully achieve the expected outcomes because the values of
ErrorCount
fail to be summed correctly #15373 - Fix the issue that Garbage Collection might work abnormally when TiDB connects to TiFlash #15505
- Fix the issue of incorrect result caused by the Inline Projection optimization #15411
- Fix the issue that the SQL Hint
INL_MERGE_JOIN
is executed incorrectly in some cases #15515 - Fix the issue that columns with the
AutoRandom
attribute are rebased when the negative number is explicitly written to these columns #15397
- Fix the issue that replication between the upstream and downstream might go wrong when the DDL job is executed using the
TiKV
- Fix the possible panic caused by transferring the leader when the Follower Read feature is enabled #7101
Tools
TiDB Lightning
- Fix the issue of data error caused by the error of character conversion when the backend is TiDB #283
TiCDC
- Fix the issue that an error is returned if the
test
schema does not exist in the downstream when MySQL sink is executing the DDL statement #353 - Support the real-time interactive mode in CDC cli #351
- Support checking whether the table in the upstream can be replicated during data replication #368
- Support asynchronous write to Kafka #344
- Fix the issue that an error is returned if the