tidb-server v1.0.7

• Optimize the FIELD_LIST command
• Fix data race of the information schema
• Avoid adding read-only statements to history
• Add the session variable to control the log query
• Fix the resource leak issue in statistics
• Fix the goroutine leak issue
• Add schema info API for the http status server
• Fix an issue about IndexJoin
• Update the behavior when RunWorker is false in DDL
• Improve the stability of test results in statistics
• Support PACK_KEYS syntax for the CREATE TABLE statement
• Add row_id column for the null pushdown schema to optimize performance

tidb-server v1.0.6

• Support the Alter Table Auto_Increment syntax
• Fix the bug in Cost Based computation and the Null Json issue in statistics
• Support the extension syntax to shard the implicit row ID to avoid write hot spot for a single table
• Fix a potential DDL issue
• Consider the timezone setting in the curtime, sysdate and curdate functions
• Support the SEPARATOR syntax in the GROUP_CONCAT function
• Fix the wrong return type issue of the GROUP_CONCAT function

tidb-server v1.0.5

• Add the max value for the current Auto_Increment ID in the Show Create Table statement.
• Fix a potential goroutine leak.
• Support outputting slow queries into a separate file.
• Load the TimeZone variable from TiKV when creating a new session.
• Support the schema state check so that the Show Create Tableand Analyze statements process the public table/index only.
• The set transaction read only should affect the tx_read_only variable.
• Clean up incremental statistic data when rolling back.
• Fix the issue of missing index length in the Show Create Table statement.

tidb-server v1.0.4

• Speed up the loading of the statistics when starting the tidb-server
• Improve the performance of the show variables statement
• Fix a potential issue when using the Add Index statement to handle the combined indexes
• Fix a potential issue when using the Rename Table statement to move a table to another database
• Accelerate the effectiveness for the Alter/Drop User statement

tidb-server v1.0.3

• Optimize the performance in transaction conflicts scenario
• Add the TokenLimit option in the config file
• Output the default database in slow query logs
• Remove the DDL statement from query duration metrics
• Optimize the query cost estimation
• Fix the index prefix issue when creating tables
• Support pushing down the expressions for the Float type to TiKV
• Fix the issue that it is slow to add index for tables with discrete integer primary index
• Reduce the unnecessary statistics updates
• Fix a potential issue during the transaction retry

To upgrade from 1.0.2 to 1.0.3, follow the rolling upgrade order of PD->TiKV->TiDB.

tidb-server v1.0.2

• Optimize the cost estimation of index point query.
• Support the Alter Table Add Column ( ColumnDef ColumnPosition) syntax.
• Optimize the queries whose where conditions are contradictory.
• Optimize the Add Index operation to rectify the progress and reduce repetitive operations.
• Optimize the Index Look Join operator to accelerate the query speed for small data size.
• Fix the issue with prefix index judgement.

tidb-server v1.0.1

• Support canceling DDL Job.
• Optimize the IN expresssion.
• Correct the result type of the Show statement.
• Support log slow query into a seperate log file.
• Fix bugs.

tidb-server v1.0.0

• The SQL query optimizer:
  • Adjust the cost model
  • Analyze pushdown
  • Function signature pushdown
• Optimize the internal data format to reduce the intrium data size
• Enhance the MySQL compatibility
• Support the NO_SQL_CACHE syntax and limit the cache usage in the storage engine
• Refactor the Hash Aggregator operator to reduce the memory usage
• Support the Stream Aggragator operator

tidb-server 1.0 Pre-GA

• The SQL query optimizer:
  • Adjust the cost model
  • Use index scan to handle the where clause with the compare expression which has different types on each side
  • Support the Greedy algorithm based Join Reorder
• Many enhancements have been introduced to be more compatible with MySQL
• Support Natural Join
• Support the JSON type (Experimental), including the query, update and index of the JSON fields
• Prune the useless data to reduce the consumption of the executor memory
• Support configuring prioritization in the SQL statements and automatically set the prioritization for some of the statements according to the query type
• Completed the expression refactor and the speed is increased by about 30%

tidb-server rc4

• The SQL query optimizer refactoring:
  • Better support for TopN queries
  • Support the automatic choice of the of the Join physical operator based on the cost
  • Improved Projection Elimination
• The version check of schema is based on Table to avoid the impact of DDL on the ongoing transactions
• Support BatchIndexJoin
• Improve the Explain statement
• Improve the Index Scan performance
• Many enhancements have been introduced to be more compatible with MySQL
• Support the JSON type and operations
• Support the configuration of query prioritizing and isolation level
• Speed up DropIndex operation