title | aliases | summary | ||
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TiDB 3.0.9 Release Notes |
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TiDB 3.0.9 was released on January 14, 2020. It includes fixes for known issues and new features. Some improvements were made to Executor, Server, DDL, Planner, TiKV, PD, Tools, and TiDB Ansible. Notable changes include support for system variables, monitoring metrics, and optimizations for transaction execution latency. Additionally, support for using backlash in the location label name and automatically creating directories for TiDB Lightning deployment was added. |
Release date: January 14, 2020
TiDB version: 3.0.9
TiDB Ansible version: 3.0.9
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 3.0.x version.
- Executor
- Fix the incorrect result when the aggregate function is applied to the
ENUM
column and the collection column #14364
- Fix the incorrect result when the aggregate function is applied to the
- Server
- Support the
auto_increment_increment
andauto_increment_offset
system variables #14396 - Add the
tidb_tikvclient_ttl_lifetime_reach_total
monitoring metric to monitor the number of pessimistic transactions with a TTL of 10 minutes #14300 - Output the SQL information in the log when the SQL query causes a panic during its execution #14322
- Add the
plan
andplan_digest
fields in the statement summary table to record theplan
that is being executed and theplan
signature #14285 - Adjust the default value of the
stmt-summary.max-stmt-count
configuration item from100
to200
#14285 - Add the
plan_digest
field in the slow query table to record theplan
signature #14292
- Support the
- DDL
- Planner
- Optimize the performance of statements such as
select max(a), min(a) from t
. If an index exists in thea
column, the statement is optimized toselect * from (select a from t order by a desc limit 1) as t1, (select a from t order by a limit 1) as t2
to avoid full table scan #14410
- Optimize the performance of statements such as
- Raftstore
- Speed up the configuration change to speed up the Region scattering #6421
- Transaction
- Add the
tikv_lock_manager_waiter_lifetime_duration
,tikv_lock_manager_detect_duration
, andtikv_lock_manager_detect_duration
monitoring metrics to monitorwaiter
s' lifetime, the time cost of detecting deadlocks, and the status ofWait
table #6392 - Optimize the following configuration items to reduce transaction execution latency caused by changing Region leader or the leader of deadlock detector in extreme situations #6429
- Change the default value of
wait-for-lock-time
from3s
to1s
- Change the default value of
wake-up-delay-duration
from100ms
to20ms
- Change the default value of
- Fix the issue that the leader of the deadlock detector might be incorrect during the Region Merge process #6431
- Add the
- Support using backlash
/
in the location label name #2083 - Fix the incorrect statistics because the tombstone store is mistakenly included by the label counter #2067
- TiDB Binlog
- Support automatically creating directories to optimize the deployment of TiDB Lightning #1105