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You are viewing the documentation of an older version of the TiDB database (TiDB v3.0).

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

TiDB RC3 Release Notes

On June 20, 2017, TiDB RC4 is released!This release is focused on MySQL compatibility, SQL optimization, stability, and performance.

Highlight

  • The privilege management is refined to enable users to manage the data access privileges using the same way as in MySQL.
  • DDL is accelerated.
  • The load balancing policy and process are optimized for performance.
  • TiDB Ansible is open sourced. By using TiDB-Ansilbe, you can deploy, upgrade, start and shutdown a TiDB cluster with one click.

Detailed updates

TiDB

  • The following features are added or improved in the SQL query optimizer:
    • Support incremental statistics
    • Support the Merge Sort Join operator
    • Support the Index Lookup Join operator
    • Support the Optimizer Hint Syntax
    • Optimize the memory consumption of the Scan, Join, Aggregation operators
    • Optimize the Cost Based Optimizer (CBO) framework
    • Refactor Expression
  • Support more complete privilege management
  • DDL acceleration
  • Support using HTTP API to get the data distribution information of tables
  • Support using system variables to control the query concurrency
  • Add more MySQL built-in functions
  • Support using system variables to automatically split a big transaction into smaller ones to commit

Placement Driver (PD)

  • Support gRPC
  • Provide the Disaster Recovery Toolkit
  • Use Garbage Collection to clear stale data automatically
  • Support more efficient data balance
  • Support hot Region scheduling to enable load balancing and speed up the data importing
  • Performance
    • Accelerate getting Client TSO
    • Improve the efficiency of Region Heartbeat processing
  • Improve the pd-ctl function
    • Update the Replica configuration dynamically
    • Get the Timestamp Oracle (TSO)
    • Use ID to get the Region information

TiKV

  • Support gRPC
  • Support the Sorted String Table (SST) format snapshot to improve the load balancing speed of a cluster
  • Support using the Heap Profile to uncover memory leaks
  • Support Streaming SIMD Extensions (SSE) and speed up the CRC32 calculation
  • Accelerate transferring leader for faster load balancing
  • Use Batch Apply to reduce CPU usage and improve the write performance
  • Support parallel Prewrite to improve the transaction write speed
  • Optimize the scheduling of the coprocessor thread pool to reduce the impact of big queries on point get
  • The new Loader supports data importing at the table level, as well as splitting a big table into smaller logical blocks to import concurrently to improve the data importing speed.