pingcap · CaitinChen · Apr 27, 2018 · Apr 27, 2018 · Apr 27, 2018
diff --git a/README.md b/README.md
@@ -116,6 +116,7 @@
 - [Frequently Asked Questions (FAQ)](FAQ.md)
 - [TiDB Best Practices](https://pingcap.github.io/blog/2017/07/24/tidbbestpractice/)
 + [Releases](releases/rn.md)
+  - [2.0](releases/2.0ga.md)
   - [2.0 RC5](releases/2rc5.md)
   - [2.0 RC4](releases/2rc4.md)
   - [2.0 RC3](releases/2rc3.md)

diff --git a/releases/2.0ga.md b/releases/2.0ga.md
@@ -0,0 +1,155 @@
+---
+title: TiDB 2.0 Release Notes
+category: Releases
+---
+
+# TiDB 2.0 Release Notes
+
+On April 27, 2018, TiDB 2.0 GA is released! Compared with TiDB 1.0, this release has great improvement in MySQL compatibility, SQL optimizer, executor, and stability.
+
+## TiDB
+
+- SQL Optimizer
+    - Use more compact data structure to reduce the memory usage of statistics information
+    - Speed up loading statistics information when starting a tidb-server process
+    - Support updating statistics information dynamically [experimental]
+    - Optimize the cost model to provide more accurate query cost evaluation
+    - Use `Count-Min Sketch` to estimate the cost of point queries more accurately
+    - Support analyzing more complex conditions to make full use of indexes
+    - Support manually specifying the `Join` order using the `STRAIGHT_JOIN` syntax
+    - Use the Stream Aggregation operator when the `GROUP BY` clause is empty to improve the performance
+    - Support using indexes for the `MAX/MIN` function
+    - Optimize the processing algorithms for correlated subqueries to support decorrelating more types of correlated subqueries and transform them to `Left Outer Join`
+    - Extend `IndexLookupJoin` to be used in matching the index prefix
+- SQL Execution Engine
+    - Refactor all operators using the Chunk architecture, improve the execution performance of analytical queries, and reduce memory usage. There is a significant improvement in the TPC-H benchmark result.
+    - Support the Streaming Aggregation operators pushdown
+    - Optimize the `Insert Into Ignore` statement to improve the performance by over 10 times
+    - Optimize the `Insert On Duplicate Key Update` statement to improve the performance by over 10 times
+    - Optimize `Load Data` to improve the performance by over 10 times
+    - Push down more data types and functions to TiKV
+    - Support computing the memory usage of physical operators, and specifying the processing behavior in the configuration file and system variables when the memory usage exceeds the threshold
+    - Support limiting the memory usage by a single SQL statement to reduce the risk of OOM
+    - Support using implicit RowID in CRUD operations
+    - Improve the performance of point queries
+- Server
+    - Support the Proxy Protocol
+    - Add more monitoring metrics and refine the log
+    - Support validating the configuration files
+    - Support obtaining the information of TiDB parameters through HTTP API
+    - Resolve Lock in the Batch mode to speed up garbage collection
+    - Support multi-threaded garbage collection
+    - Support TLS
+- Compatibility
+    - Support more MySQL syntaxes
+    - 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 displaying the table creating time in `Information_Schema`
+    - Fix the issue that the return types of some functions/expressions differ from MySQL
+    - Improve compatibility with JDBC
+    - Support more SQL Modes
+- DDL
+    - Optimize the `Add Index` operation to greatly improve the execution speed in some scenarios
+    - Attach a lower priority to the `Add Index` operation to reduce the impact on online business
+    - Output more detailed status information of the DDL jobs in `Admin Show DDL Jobs`
+    - Support querying the original statements of currently running DDL jobs using `Admin Show DDL Job Queries JobID`
+    - Support recovering the index data using `Admin Recover Index` for disaster recovery
+    - Support modifying Table Options using the `Alter` statement
+
+## PD
+
+- Support `Region Merge`, to merge empty Regions after deleting data [experimental]
+- Support `Raft Learner` [experimental]
+- Optimize the scheduler
+    - Make the scheduler to adapt to different Region sizes
+    - Improve the priority and speed of restoring data during TiKV outage
+    - Speed up data transferring when removing a TiKV node
+    - Optimize the scheduling policies to prevent the disks from becoming full when the space of TiKV nodes is insufficient
+    - Improve the scheduling efficiency of the balance-leader scheduler
+    - Reduce the scheduling overhead of the balance-region scheduler
+    - Optimize the execution efficiency of the the hot-region scheduler
+- Operations interface and configuration
+    - Support TLS
+    - Support prioritizing the PD leaders
+    - Support configuring the scheduling policies based on labels
+    - Support configuring stores with a specific label not to schedule the Raft leader
+    - Support splitting Region manually to handle the hotspot in a single Region
+    - Support scattering a specified Region to manually adjust Region distribution in some cases
+    - Add check rules for configuration parameters and improve validity check of the configuration items
+- Debugging interface
+    - Add the `Drop Region` debugging interface
+    - Add the interfaces to enumerate the health status of each PD
+- Statistics
+    - Add statistics about abnormal Regions
+    - Add statistics about Region isolation level
+    - Add scheduling related metrics
+- Performance 
+    - Keep the PD leader and the etcd leader together in the same node to improve write performance
+    - Optimize the performance of Region heartbeat
+
+## TiKV
+
+- Features
+    - Protect critical configuration from incorrect modification
+    - Support `Region Merge` [experimental]
+    - Add the `Raw DeleteRange` API
+    - Add the `GetMetric` API
+    - Add `Raw Batch Put`, `Raw Batch Get`, `Raw Batch Delete` and `Raw Batch Scan`
+    - Add Column Family options for the RawKV API and support executing operation on a specific Column Family
+    - Support Streaming and Streaming Aggregation in Coprocessor
+    - Support configuring the request timeout of Coprocessor
+    - Carry timestamps with Region heartbeats
+    - Support modifying some RocksDB parameters online, such as `block-cache-size`
+    - Support configuring the behavior of Coprocessor when it encounters some warnings or errors
+    - Support starting in the importing data mode to reduce write amplification during the data importing process
+    - Support manually splitting Region in halves
+    - Improve the data recovery tool `tikv-ctl`
+    - Return more statistics in Coprocessor to guide the behavior of TiDB
+    - Support the `ImportSST` API to import SST files [experimental]
+    - Add the TiKV Importer binary to integrate with TiDB Lightning to import data quickly [experimental]
+- Performance
+    - Optimize read performance using `ReadPool` and increase the `raw_get/get/batch_get` by 30%
+    - Improve metrics performance
+    - Inform PD immediately once the Raft snapshot process is completed to speed up balancing
+    - Solve performance jitter caused by RocksDB flushing
+    - Optimize the space reclaiming mechanism after deleting data
+    - Speed up garbage cleaning while starting the server
+    - Reduce the I/O overhead during replica migration using `DeleteFilesInRanges`
+- Stability
+    - Fix the issue that gRPC call does not get returned when the PD leader switches
+    - Fix the issue that it is slow to offline nodes caused by snapshots
+    - Limit the temporary space usage consumed by migrating replicas
+    - Report the Regions that cannot elect a leader for a long time
+    - Update the Region size information in time according to compaction events
+    - Limit the size of scan lock to avoid request timeout
+    - Limit the memory usage when receiving snapshots to avoid OOM
+    - Increase the speed of CI test
+    - Fix the OOM issue caused by too many snapshots
+    - Configure `keepalive` of gRPC
+    - Fix the OOM issue caused by an increase of the Region number
+
+## TiSpark
+
+TiSpark uses a separate version number. The current TiSpark version is 1.0 GA. The components of TiSpark 1.0 provide distributed computing of TiDB data using Apache Spark.
+
+- Provide a gRPC communication framework to read data from TiKV
+- Provide encoding and decoding of TiKV component data and communication protocol
+- Provide calculation pushdown, which includes:
+    - Aggregate pushdown
+    - Predicate pushdown
+    - TopN pushdown
+    - Limit pushdown
+- Provide index related support
+    - Transform predicate into Region key range or secondary index
+    - Optimize `Index Only` queries
+    - Optimize table scan when runtime index degenerates
+- Provide cost-based optimization
+    - Support statistics
+    - Select index
+    - Estimate broadcast table cost
+- Provide support for multiple Spark interfaces
+    - Support Spark Shell
+    - Support ThriftServer/JDBC
+    - Support Spark-SQL interaction
+    - Support PySpark Shell
+    - Support SparkR
diff --git a/releases/rn.md b/releases/rn.md
@@ -5,6 +5,7 @@ category: release
 
 # TiDB Release Notes
 
+  - [2.0](2.0ga.md)
   - [2.0 RC5](2rc5.md)
   - [2.0 RC4](2rc4.md)
   - [2.0 RC3](2rc3.md)