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Latest Release
1268 days ago
Changelog History
Page 2
Changelog History
Page 2
-
v4.0.0-beta.1 Changes
February 28, 2020Compatibility Changes
- Modify the
password
field name toauthentication_string
in themysql.user
system table to make it consistent with MySQL 5.7 #14598 - π§ Adjust the default value of the
txn-total-size-limit
configuration item from1GB
to100MB
#14522 - π Support dynamically modifying or updating configuration items read from PD #14750 #14303 #14830
π New Features
- Support querying slow logs of any time in the
SLOW_QUERY / CLUSTER_SLOW_QUERY
system table #14840 #14878 - π Support SQL performance diagnosis
#14843 #14810 #14835 #14801 #14743
#14718 #14721 #14670 #14663 #14668
#14896 - π Support the Sequence function #14731 #14589 #14674 #14442 #14303 #14830
- π Support dynamically modifying or updating configuration items read from PD #14750 #14303 #14830
- β Add a feature of automatically reading data from different roles according to the load balancing policy and add the
leader-and-follower
system variable to enable this feature #14761 - β Add the
Coercibility
function #14739 - π Support setting TiFlash replicas in the partitioned table #14735 #14713 #14644
- π Improve the privilege check for the
SLOW_QUERY
table #14451 - π Support automatically write the intermediate results to the disk file if the memory is insufficient when using a SQL join #14708 #14279
- π Support checking table partitions by querying the
information_schema.PARTITIONS
system table #14347 - β Add the
json_objectagg
aggregate function #11154 - π Support logging rejected connection attempts in the audit log #14594
- β Add the
max-server-connections
configuration item (4096
by default) to control the number of connections to a single server #14409 - π Support the isolation read specifying multiple storage engines at the server level #14440
- β‘οΈ Optimize the cost model of the
Apply
operator and theSort
operator to improve stability #13550 #14708
π Bugfix
- π Fix the issue that an error is reported when creating
view
with a column name that exceeds 64 characters #14850 - π Fix the issue that duplicate data exists in
information_schema.views
because thecreate or replace view
statement is incorrectly processed #14832 - π Fix the incorrect results of
BatchPointGet
whenplan cache
is enabled #14855 - π Fix the issue that data is inserted into the wrong partitioned table after the timezone is modified #14370
- π Fix the panic occurred when rebuilding expression using the invalid name of the
IsTrue
function during the outer join simplification #14515 - π Fix the the incorrect privilege check for the
show binding
statement #14443
- Modify the
-
v4.0.0-beta Changes
January 17, 2020π Improvements
- Increase the accuracy of calculating the cost of
Index Join
by considering the row counts of both driving tables and driven tables #12085 - π Improve the performance when the columns involved in a query can be fully covered by indexes #12022
- π Improve the performance of table query by supporting the Index Merge feature #10121 #10512 #11245 #12225 #12248 #12305 #12843
- π Improve the performance of Range calculation and reduce the CPU overhead by caching index results and eliminating duplicate results #12856
- π Decouple the level of slow logs from the level of ordinary logs #12359
- 0οΈβ£ Increase the default value of the
query-log-max-len
parameter to4096
to reduce the number of truncated SQL outputs. This parameter can be adjusted dynamically. #12491 - Convert a narrow data range of the discrete type into
point set
and useCMSketch
to improve the estimation accuracy when estimating the number of rows #11524 - Extract the
TopN
information fromCMSketch
for normalAnalyze
and separately maintain the frequently occurring values #11409 - π Support dynamically adjusting the depth and width of
CMSketch
and the number ofTopN
information #11278 - π Support automatically capturing and evolving SQL Binding #13199
- π Optimize the encoding format of communication with TiKV by using
Chunk
to improve communication performance #12023 #12536 #12613 #12621 #12899 #13060 #13349 - π Support the new row store format to improve the performance of the wide table #12634
- π Improve the stability of
Kill
#10841 - π Improve the performance of
IndexLookupJoin
and reduce memory consumption during execution by splittingIndexLookupJoin
intoIndexHashJoin
andIndexMergeJoin
#8861 #12139 #12349 #13238 #13451 #13714 - π² Output the detailed
backoff
information of TiKV RPC in the slow log to facilitate troubleshooting #13770 - β‘οΈ Optimize and unify the format of the memory statistics in the expensive log #12809
- β‘οΈ Optimize the explicit format of
EXPLAIN
and support outputting information about the operatorβs usage of memory and disk - Optimize the check for duplicate values in
LOAD DATA
based on the transaction size and support setting the transaction size by configuring thetidb_dml_batch_size
parameter #11132 - β‘οΈ Optimize the
Recover Binlog
interface to ensure waiting all transactions to be committed before returning to the client #13740 - π Optimize the performance of
LOAD DATA
by separating the data preparing routine and the commit routine and assigning the workload to different Workers #11533 #11284
π New Features
- π Support using the
LIKE
orWHERE
clause inADMIN SHOW DDL JOBS
for conditional filtering #12484 - Add the
TIDB_ROW_ID_SHARDING_INFO
column in theinformation_schema.tables
table to output theRowID
scattering information (for example, the value of theSHARD_ROW_ID_BITS
column in tableA
is"SHARD_BITS={bit_number}"
) #13418 - β Add the
oom-use-tmp-storage
parameter (true
by default) to control whether to use temporary files to cache intermediate results when the memory usage for the execution of a single SQL statement exceedsmem-quota-query
and the SQL containsHash Join
#11832 #11937 #12116 #12067 - π Support querying the binlog statuses enabled by TiDB servers in the cluster through the HTTP
info/all
interface #13025 - π Support adding the
AutoRandom
keyword in the column attribute to control whether the system automatically assigns a random integer to the primary key, which avoids the hotspot problem caused by theAUTO_INCREMENT
primary key #13127 - π Support Table Locks #11038
- π Support the MySQL-compatible
Read Committed
transaction isolation level when using the pessimistic transaction mode #14087 - π Support large-sized transactions. The transaction size is limited by the size of the physical memory.
- π Support hexadecimal and binary expressions as separators in
LOAD DATA
#11029 #13914 #13692 #13686 #11415 #13927 #13764 #13720 - β Add 15 SQL hints to control the behavior of the optimizer and make the optimizer more stable
π Changed Behaviors
- β‘οΈ Optimize the error code of SQL error messages to eliminate the
ERROR 1105 (HY000)
code(theUnknown Error
type) - β‘οΈ Print the log or cancel the SQL execution when the memory used during the execution of
INSERT
/REPLACE
/DELETE
/UPDATE
exceeds the limit specified by theMemQuotaQuery
configuration item. The actual behavior depends on theOOMAction
configuration #14179 #14289 #14299
π Bugfix
- Increase the accuracy of calculating the cost of
-
v3.1.2
June 04, 2020 -
v3.1.0 Changes
April 16, 2020Compatibility Changes
- π Support directly stopping starting of TiDB if the HTTP listening port is unavailable when the
report-status
configuration item is enabled #16291
π New Features
- π Support displaying the information of Coprocessor tasks in
explain format = "dot"
#16125 - β¬οΈ Reduce the redundant stack information of log using the
disable-error-stack
configuration item #16182
π Bug Fixes
- π Fix the panic issue caused by the merge join operation in some scenarios #15920
- π Fix the issue that some expressions are repeatedly counted in selectivity calculation #16052
- π Fix the panic issue when loading the statistics information in extreme cases #15710
- π Fix the issue that an error is returned in some cases when equivalent expressions cannot be recognized in SQL query #16015
- π Fix the issue that an error is returned when querying the view of one database from another database #15867
- π Fix the panic issue that occurs when the column is handled using
fast analyze
#16080 - π Fix the incorrect character set of the
current_role
print result #16084 - π² Refine the log of MySQL connection handshake error #15799
- π Fix the panic issue caused by port probing after the audit plugin is loaded #16065
- π Fix the panic issue of the sort operator on left join because the
TypeNull
class is mistaken as a variable-length type #15739 - π Fix the issue of inaccurate count of monitoring session retry error #16120
- Fix the issue of wrong results of
weekday
in theALLOW_INVALID_DATES
mode #16171 - π Fix the issue that Garbage Collection (GC) might not work normally when the cluster has TiFlash nodes #15761
- π Fix the issue that TiDB goes out of memory (OOM) when users set a large partition count when creating hash partitioned table #16219
- π Fix the issue that warnings are mistaken as errors, and make the
union
statement have the same behavior as theselect
statement #16138 - π Fix the execution error when TopN is pushed down to mocktikv #16200
- Increase the initial length of
chunk.column.nullBitMap
to avoid unnecessary cost ofruntime.growslice
#16142
- π Support directly stopping starting of TiDB if the HTTP listening port is unavailable when the
-
v3.1.0-rc Changes
April 02, 2020π New Features
- π Use the binary search to re-implement partition pruning for better performance #15678
- π Support using the
RECOVER
syntax to recover the truncated table #15460 - β Add
AUTO_RANDOM
ID cache for retrying statement and recovering table #15393 - π Support restoring the state of the
AUTO_RANDOM
ID allocator using therecover table
statement #15393 - π Support
YEAR
,MONTH
, andTO_DAY
functions as the partitioning keys of the Hash partitioned table #15619 - β Add the table ID to the schema-change related tables only when keys need to be locked in the
SELECT... FOR UPDATE
statement #15708 - β Add the feature of automatically reading data from different roles according to the load balancing policy and add the leader-and-follower system variable to enable this feature #15721
- π Support dynamically updating the TLS certificate every time TiDB establishes a new connection to update expired client certificate without restarting the RPC client side #15163
- β¬οΈ Upgrade PD Client to support loading the latest certificate every time TiDB establishes a new connection #15425
- π§ Forcibly use the HTTPS protocol with the configured TLS certificates between a TiDB server and a PD server, or between two TiDB servers when
cluster-ssl-*
is configured #15430 - β Add the MySQL-compatible
--require-secure-transport
startup option to force the client to enable TLS authentication during the configuration #15442 - β Add the
cluster-verify-cn
configuration item. After configuration, the status service can only be used when with the corresponding CN certificate #15137
π Bug Fixes
- π Use the binary search to re-implement partition pruning for better performance #15678
- π Fix the information schema error caused by frequently updating the TiFlash replica #14884
- Fix the issue that
last_insert_id
is incorrectly generated when applyingAUTO_RANDOM
#15149 * Fix the issue that updating the status of TiFlash replica might cause the DDL operation to get stuck #15161 * ForbidAggregation
pushdown andTopN
pushdown when there are predicates that can not be pushed down #15141 - Forbid the nested
view
creation #15440 - π Fix the error occurred when executing
SELECT CURRENT_ROLE()
afterSET ROLE ALL
#15570 - Fix the failure to identify the
view
name when executing theselect view_name.col_name from view_name
statement #15573 - π Fix the issue that an error might occur when pre-processing DDL statements during the write of binlog information #15444
- π Fix the panic occurred when accessing both
view
s and partitioned tables #15560 - π Fix the error occurred when executing the
VALUES
function with theupdate duplicate key
statement that contains thebit(n)
data type #15487 - π Fix the issue that the specified maximum execution time fails to take effect in some scenarios #15616
- π Fix the issue that fails to check whether the current ReadEngine contains TiKV server when generating the execution plan using
Index Scan
#15773
-
v3.1.0-beta.2 Changes
March 09, 2020π New Features
- π Support adding the
AutoRandom
keyword in the column attribute to enable TiDB to automatically assign random integers to the primary key, which avoids the write hot spot caused by theAUTO_INCREMENT
primary key #14555 - π Support creating or deleting column store replicas through DDL statements #14537
- β Add the feature that the optimizer can independently select different storage engines #14537
- β Add the feature that the SQL hint supports different storage engines #14537
- Support reading data from followers by using the
tidb_replica_read
system variable #13464
- π Support adding the
-
v3.1.0-beta.1 Changes
January 10, 2020π (There is no public release note for this version of TiDB Server)
-
v3.0.19 Changes
September 25, 2020π Improvements
- π Mitigate the impact of failure recovery on QPS performance #19764
- π Support adjusting the concurrency of the
union
operator #19885
π Bug Fixes
- π Fix the query error that occurs when the
slow-log
file does not exist #20050 - Add the privilege check for
SHOW STATS_META
andSHOW STATS_BUCKET
#19759 - Forbid changing the decimal type to the integer type #19681
- π Fix the issue that alter enum/set type does not check constraint #20045
- π Fix the bug that tidb-server does not release table locks after a panic #20021
- π Fix the bug that the
OR
operator is not handled correctly in theWHERE
clause #19901
-
v3.0.18 Changes
August 21, 2020π Bug Fixes
- π Fix the issue that the wrong handling of the
decimal
type by theHash
function causes the wrong HashJoin result #19185 - π Fix the issue that the wrong handling of the
set
andenum
types by theHash
function causes the wrong HashJoin result #19175 - π Fix the issue that the check for duplicate keys fails in the pessimistic locking mode #19236
- π Fix the issue that the
Apply
andUnion Scan
operators cause the wrong execution result #19297 - π Fix the issue that some cached execution plans are incorrectly executed in transaction #19274
- π Fix the issue that the wrong handling of the
-
v3.0.17 Changes
August 03, 2020π Improvements
- Ease the impact of statistics feedback on the cluster #18770
- Limit batch split count for one request #18694
- π· Accelerate
/tiflash/replica
HTTP API when there are many history DDL jobs in the TiDB cluster #18386 - π Improve row count estimation for index equal condition #17609
- Speed up the execution of
kill tidb conn_id
#18506
π Bug Fixes
- Return the actual error message instead of an empty set when a query which contains
IndexHashJoin
orIndexMergeJoin
encounters a panic #18498 - π Fix the unknown column error for SQL statements like
SELECT a FROM t HAVING t.a
#18432 - Forbid adding a primary key for a table when the table has no primary key or when the table already has an integer primary key #18342
- Return an empty set when executing
EXPLAIN FORMAT="dot" FOR CONNECTION
#17157 - Fix
STR_TO_DATE
's handling for format token '%r', '%h' #18725