title | category |
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TiDB 2.0 RC3 Release Notes |
Releases |
On March 23, 2018, TiDB 2.0 RC3 is released. This release has great improvement in MySQL compatibility, SQL optimization and stability.
- Fix the wrong result issue of
MAX/MIN
in some scenarios - Fix the issue that the result of
Sort Merge Join
does not show in order of Join Key in some scenarios - Fix the error of comparison between
uint
andint
in boundary conditions - Optimize checks on length and precision of the floating point type, to improve compatibility with MySQL
- Improve the parsing error log of time type and add more error information
- Improve memory control and add statistics about
IndexLookupExecutor
memory - Optimize the execution speed of
ADD INDEX
to greatly increase the speed in some scenarios - Use the Stream Aggregation operator when the
GROUP BY
substatement is empty, to increase the speed - Support closing the
Join Reorder
optimization in the optimizer usingSTRAIGHT_JOIN
- Output more detailed status information of DDL jobs in
ADMIN SHOW DDL JOBS
- Support querying the original statements of currently running DDL jobs using
ADMIN SHOW DDL JOB QUERIES
- Support recovering the index data using
ADMIN RECOVER INDEX
for disaster recovery - Attach a lower priority to the
ADD INDEX
operation to reduce the impact on online business - Support aggregation functions with JSON type parameters, such as
SUM/AVG
- Support modifying the
lower_case_table_names
system variable in the configuration file, to support the OGG data synchronization tool - Improve compatibility with the Navicat management tool
- Support using implicit RowID in CRUD operations
- Support Region Merge, to merge empty Regions or small Regions after deleting data
- Ignore the nodes that have a lot of pending peers during adding replicas, to improve the speed of restoring replicas or making nodes offline
- Fix the frequent scheduling issue caused by a large number of empty Regions
- Optimize the scheduling speed of leader balance in scenarios of unbalanced resources within different labels
- Add more statistics about abnormal Regions
- Support Region Merge
- Inform PD immediately once the Raft snapshot process is completed, to speed up balancing
- Add the Raw DeleteRange API
- Add the GetMetric API
- Reduce the I/O fluctuation caused by RocksDB sync files
- Optimize the space reclaiming mechanism after deleting data
- Improve the data recovery tool
tikv-ctl
- Fix the issue that it is slow to make nodes down caused by snapshot
- Support streaming in Coprocessor
- Support Readpool and increase the
raw_get/get/batch_get
by 30% - Support configuring the request timeout of Coprocessor
- Support streaming aggregation in Coprocessor
- Carry time information in Region heartbeats
- Limit the space usage of snapshot files to avoid consuming too much disk space
- Record and report the Regions that cannot elect a leader for a long time
- Speed up garbage cleaning when starting the server
- Update the size information about the corresponding Region according to compaction events
- Limit the size of
scan lock
to avoid request timeout - Use
DeleteRange
to speed up Region deletion - Support modifying RocksDB parameters online