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TiDB 5.0.1 Release Notes
Release date: April 24, 2021
TiDB version: 5.0.1
Compatibility change
- The default value of the
committer-concurrency
configuration item is changed from16
to128
.
Improvements
TiDB
- Support the built-in function
VITESS_HASH()
#23915
- Support the built-in function
TiKV
- Use
zstd
to compress the Region snapshot #10005
- Use
PD
Tools
Backup & Restore (BR)
- Remove some misleading information from the summary log #1009
Bug Fixes
TiDB
- Fix the issue that the execution result of project elimination might be wrong when the projection result is empty #24093
- Fix the issue of wrong query results when a column contains
NULL
values in some cases #24063 - Forbid generating MPP plans when the scan contains virtual columns #24058
- Fix the wrong reuse of
PointGet
andTableDual
in Plan Cache #24043 - Fix the error that occurs when the optimizer builds the
IndexMerge
plan for clustered indexes #24042 - Fix the type inference of the BIT-type errors #24027
- Fix the issue that some optimizer hints do not take effect when the
PointGet
operator exists #23685 - Fix the issue that DDL operations might fail when rolling back due to an error #24080
- Fix the issue that the index range of the binary literal constant is incorrectly built #24041
- Fix the potential wrong results of the
IN
clause in some cases #24023 - Fix the wrong results of some string functions #23879
- Users now need both
INSERT
andDELETE
privileges on a table to performREPLACE
operations #23939 - Fix the performance regression when executing the point query #24070
- Fix the wrong
TableDual
plans caused by incorrectly comparing binaries and bytes #23918
TiKV
- Fix the issue that the coprocessor fails to properly handle the signed or unsigned integer types in the
IN
expression #10018 - Fix the issue of many empty Regions after batch ingesting SST files #10015
- Fix the potential panic that occurs when the input of
cast_string_as_time
is invalid UTF-8 bytes #9995 - Fix a bug that TiKV cannot start up after the file dictionary file is damaged #9992
- Fix the issue that the coprocessor fails to properly handle the signed or unsigned integer types in the
TiFlash
- Fix the issue that the storage engine fails to remove the data of some ranges
- Fix the issue of incorrect results when casting the time type to the integer type
- Fix a bug that the
receiver
cannot find corresponding tasks within 10 seconds - Fix the issue that there might be invalid iterators in
cancelMPPQuery
- Fix a bug that the behavior of the
bitwise
operator is different from that of TiDB - Fix the alert issue caused by overlapping ranges when using the
prefix key
- Fix the issue of incorrect results when casting the string type to the integer type
- Fix the issue that consecutive and fast writes might make TiFlash out of memory
- Fix the issue that duplicated column names will make TiFlash raise errors
- Fix the issue that TiFlash fails to parse MPP plans
- Fix the potential issue that the exception of null pointer might be raised during the table GC
- Fix the TiFlash panic issue that occurs when writing data to dropped tables
- Fix the issue that TiFlash might panic during BR restore
Tools
TiDB Lightning
- Fix the issue of the inaccurate table count in the progress log during the import #1005
Backup & Restore (BR)
TiCDC
- Fix the concurrency issue in Unified Sorter and filter the unhelpful error messages #1678
- Fix a bug that the creation of redundant directories might interrupt the replication with MinIO #1672
- Set the default value of the
explicit_defaults_for_timestamp
session variable toON
to make the MySQL 5.7 downstream keep the same behavior with the upstream TiDB #1659 - Fix the issue that the incorrect handling of
io.EOF
might cause replication interruption #1648 - Correct the TiKV CDC endpoint CPU metric in the TiCDC dashboard #1645
- Increase
defaultBufferChanSize
to avoid replication blocking in some cases #1632
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