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TiDB 4.0 GA Release Notes
Release date: May 28, 2020
TiDB version: 4.0.0
Compatibility Changes
TiDB
- Optimize the error message of the large-sized transactions for easier troubleshooting #17219
TiCDC
Important Bug Fixes
TiKV
TiFlash
- Fix the possible data loss issue that occurs when the system panics because of incorrect processing logic of
Raft Admin Command
- Fix the possible data loss issue that occurs when the system panics because of incorrect processing logic of
New Features
TiDB
- Add the
committer-concurrency
configuration item to control the number ofgoroutines
in the retry-commit phase #16849 - Support the
show table partition regions
syntax #17294 - Add the
tmp-storage-quota
configuration item to limit the temporary disk space used by the TiDB server #15700 - Support checking whether the partitioned table uses a unique prefix index when creating and changing tables #17213
- Support the
insert/replace into tbl_name partition
(partition_name_list
) statement #17313 - Support checking the value of
collations
when using theDistinct
function #17240 - Support the
is null
filter condition during the Hash partition pruning #17310 - Support
admin check index
,admin cleanup index
, andadmin recover index
in partitioned tables #17392 #17405 #17317 - Support range partition pruning for the
in
expressions #17320
- Add the
TiFlash
- Support filtering out the data corresponding to the qualified
TSO
through themin commit ts
value of theLock CF
when the Learner reads the data - Add the feature that the system explicitly reports an error to avoid incorrect calculation results when the value of
TIMESTAMP
type is less than1970-01-01 00:00:00
- Support using flags in regular expressions when searching logs
- Support filtering out the data corresponding to the qualified
TiKV
- Support collation rules of
ascii_bin
andlatin1_bin
encoding #7919
- Support collation rules of
PD
- Support specifying the reverse proxy resource prefix for built-in TiDB Dashboard #2457
- Support returning the
pending peer
anddown peer
information in interfaces of the PD client Region #2443 - Add monitoring items such as
Direction of hotspot move leader
,Direction of hotspot move peer
, andHot cache read entry number
#2448
Tools
- Backup & Restore (BR)
- Support the backup and restore of
Sequence
andView
#242
- Support the backup and restore of
- TiCDC
- Support checking the validity of
Sink URI
when creatingChangefeed
#561 - Support checking whether the PD and TiKV versions meet the system requirements during system startup #570
- Support scheduling multiple tables in the same scheduling task generation cycle #572
- Add information about node roles in HTTP API #591
- Support checking the validity of
- Backup & Restore (BR)
Bug Fixes
TiDB
- Fix the issue of unexpected timeouts when sending and receiving messages by disabling TiDB to send batch commands to TiFlash #17307
- Fix the issue of incorrectly distinguishing signed and unsigned integers during partition pruning, which improves performance #17230
- Fix the issue of upgrade failure from v3.1.1 to v4.0 because of the incompatible
mysql.user
table #17300 - Fix the issue of incorrect selection of the partition in the
update
statement #17305 - Fix system panics when receiving an unknown error message from TiKV #17380
- Fix system panics caused by incorrect processing logic when creating the table that is
key
partitioned #17242 - Fix the issue that the wrong
Index Merge Join
plan is selected because of incorrect optimizer processing logic #17365 - Fix the issue of inaccurate
duration
monitoring metric of theSELECT
statement in Grafana #16561 - Fix the issue that the GC worker is blocked when the system error occurs #16915
- Fix the issue that the
UNIQUE
constraint on a boolean column results in an incorrect result in a comparison #17306 - Fix system panics caused by incorrect processing logic when
tidb_opt_agg_push_down
is enabled and the aggregation function pushes down the partitioned table #17328 - Fix the issue of accessing failed TiKV nodes in some cases #17342
- Fix the issue that the
isolation-read
configuration item intidb.toml
does not take effect #17322 - Fix the issue of incorrect order of output results due to incorrect processing logic when
hint
is used to enforce the stream aggregation #17347 - Fix the behavior that
insert
processes DIV under differentSQL_MODE
#17314
TiFlash
- Fix the issue that the matching behavior of regular expressions in the search log feature is inconsistent with other components
- Fix the issue of excessive restart time when nodes write large amounts of data by disabling the delay processing optimization of
Raft Compact Log Command
by default - Fix the issue that the system fails to start because TiDB incorrectly processes the
DROP DATABASE
statement in some scenarios - Fix the issue that the method of collecting CPU information in
Server_info
is different from that in other components - Fix the issue that the error
Too Many Pings
is reported when theQuery
statement is executed ifbatch coprocessor
is enabled - Fix the issue that Dashboard fails to display the correct
deploy path
information because TiFlash does not report the related information
TiKV
- Fix the
DefaultNotFound
error that occurs when backing up using BR #7937 - Fix system panics caused by out-of-order
ReadIndex
packets #7930 - Fix the issue that an unexpected error is returned because the read request callback function is not called #7921
- Fix system panics caused by incorrectly removing snapshot files when TiKV is restarted #7927
- Fix the issue that the
master key
cannot be rotated due to incorrect processing logic in storage encryption #7898 - Fix the issue that the received
lock cf
file of the snapshot is not encrypted when the storage encryption is enabled #7922
- Fix the
PD
Tools
- Backup & Restore (BR)
- Fix the issue that the data restoration fails due to network issues when BR restores data from cloud storage #298
- TiCDC
- Backup & Restore (BR)
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