You are viewing the documentation of an older version of the TiDB database (TiDB v3.1).

It is recommended that you use the latest LTS version of the TiDB database.

TiDB 1.1 Alpha Release Notes

On January 19, 2018, TiDB 1.1 Alpha is released. This release has great improvement in MySQL compatibility, SQL optimization, stability, and performance.


  • SQL parser
    • Support more syntax
  • SQL query optimizer
    • Use more compact structure to reduce statistics info memory usage
    • Speed up loading statistics info when starting tidb-server
    • Provide more accurate query cost evaluation
    • Use Count-Min Sketch to estimate the cost of queries using unique index more accurately
    • Support more complex conditions to make full use of index
  • SQL executor
    • Refactor all executor operators using Chunk architecture, improve the execution performance of analytical statements and reduce memory usage
    • Optimize performance of the INSERT IGNORE statement
    • Push down more types and functions to TiKV
    • Support more SQL_MODE
    • Optimize the Load Data performance to increase the speed by 10 times
    • Optimize the Use Database performance
    • Support statistics on the memory usage of physical operators
  • Server
    • Support the PROXY protocol


  • Add more APIs
  • Support TLS
  • Add more cases for scheduling Simulator
  • Schedule to adapt to different Region sizes
  • Fix some bugs about scheduling


  • Support Raft learner
  • Optimize Raft Snapshot and reduce the I/O overhead
  • Support TLS
  • Optimize the RocksDB configuration to improve performance
  • Optimize count (*) and query performance of unique index in Coprocessor
  • Add more failpoints and stability test cases
  • Solve the reconnection issue between PD and TiKV
  • Enhance the features of the data recovery tool tikv-ctl
  • Support splitting according to table in Region
  • Support the Delete Range feature
  • Support setting the I/O limit caused by snapshot
  • Improve the flow control mechanism
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