TiFlash v5.4.0

Improvements

• Optimize the communication of local operators
• Increase the non-temporary thread count of gRPC to avoid the frequent creation or destruction of threads

Bug fixes

• Fix the issue that TiFlash might panic when an MPP query is stopped
• Fix the issue that queries with the where <string> clause return wrong results
• Fix the potential issue of data inconsistency that might occur when setting the column type of an integer primary key to a larger range
• Fix the issue that when an input time is earlier than 1970-01-01 00:00:01 UTC, the behavior of unix_timestamp is inconsistent with that of TiDB or MySQL
• Fix the issue that TiFlash might return the EstablishMPPConnection error after it is restarted
• Fix the issue that the CastStringAsDecimal behavior is inconsistent in TiFlash and in TiDB/TiKV
• Fix the issue that the DB::Exception: Encode type of coprocessor response is not CHBlock error is returned in the query result
• Fix the issue that the castStringAsReal behavior is inconsistent in TiFlash and in TiDB/TiKV
• Fix the issue that the returned result of the date_add_string_xxx function in TiFlash is inconsistent with that in MySQL

V5.4.0

v5.4.0-alpha

fix inspect won't run in imitative mode (#3807) (#3809)

TiFlash v5.0.6

Bug fixes

• Fix potential data inconsistency after altering a primary key column to a larger int data type
• Fix the issue that TiFlash fails to start up on some platforms, such as ARM, due to the absence of the libnsl.so library
• Fix the issue that the Store size metric does not match the actual data size on a disk
• Fix the issue that TiFlash crashes due to a Cannot open file error
• Fix occasional crashes of TiFlash when an MPP query is killed
• Fix the unexpected error 3rd arguments of function substringUTF8 must be constants
• Fix query failures caused by excessive OR conditions
• Fix the bug that results of where <string> are wrong
• Fix inconsistent behaviors of CastStringAsDecimal between TiFlash and TiDB/TiKV
• Fix query failures caused by the error different types: expected Nullable(Int64), got Int64
• Fix query failures caused by the error Unexpected type of column: Nullable(Nothing)
• Fix query failures caused by overflow when comparing data in the DECIMAL data type

TiFlash v4.0.16

Bug fixes

• Fix the issue that TiFlash fails to start up on some platforms due to the absence of library nsl

TiFlash v5.3.0

Improvements

• Improve the execution efficiency of the TableScan operator greatly
• Improve the execution efficiency of the Exchange operator
• Reduce write amplification and memory usage during GC of the storage engine (experimental feature)
• Improve the stability and availability of TiFlash when TiFlash restarts, which reduces possible query failures following the restart
• Support pushing down multiple new String and Time functions to the MPP engine
• String functions: LIKE pattern, FORMAT(), LOWER(), LTRIM(), RTRIM(), SUBSTRING_INDEX(), TRIM(), UCASE(), UPPER()
• Mathematical functions: ROUND (decimal, int)
• Date and time functions: HOUR(), MICROSECOND(), MINUTE(), SECOND(), SYSDATE()
• Type conversion function: CAST(time, real)
• Aggregation functions: GROUP_CONCAT(), SUM(enum)
• Support 512-bit SIMD
• Enhance the cleanup algorithm for outdated data to reduce disk usage and read files more efficiently
• Fix the issue that dashboard does not display memory or CPU information in some non-Linux systems
• Unify the naming style of TiFlash log files (keep the naming style consistent with that of TiKV) and support dynamic modification of logger.count and logger.size
• Improve the data validation capability of column-based files (checksums, experimental feature)

Bug Fixes

• Fix the issue of inaccurate TiFlash Store Size statistics
• Fix the issue that TiFlash fails to start up on some platforms due to the absence of library nsl
• Block the infinite wait of wait index when writing pressure is heavy (a default timeout of 5 minutes is added), which prevents TiFlash from waiting too long for data replication to provide services
• Fix the slow and no result issues of the log search when the log volume is large
• Fix the issue that only the most recent logs can be searched when searching old historical logs
• Fix the possible wrong result when a new collation is enabled
• Fix the possible parsing errors when an SQL statement contains extremely long nested expressions
• Fix the possible Block schema mismatch error of the Exchange operator
• Fix the possible Can't compare error when comparing Decimal types
• Fix the 3rd arguments of function substringUTF8 must be constants error of the left/substring function

TiFlash v5.2.3

FIX exception: GC removed normal file which just created (#3216) (#3228)

TiFlash v5.2.2

Bug Fixes

• Fix the issue that TiFlash fails to start up under platform without library nsl

TiFlash v5.1.3

There is no release note for this version.

TiFlash v5.1.2

Improvements

• Support the DATE() function
• Add write throughput per instance to Grafana panels
• Optimize the performance of the leader-read process
• Accelerate the process of canceling MPP tasks

Bug Fixes

• Fix the issue of unexpected results when TiFlash fails to establish MPP connections
• Fix the potential issue of data inconsistency that occurs when TiFlash is deployed on multiple disks
• Fix a bug that MPP queries get wrong results when TiFlash server is under high load
• Fix a potential bug that MPP queries hang forever
• Fix the issue of concurrency problem between store initialization and DDL
• Fix a bug of incorrect results that occurs when queries contain filters like CONSTANT < | <= | > | >= COLUMN
• Fix the potential panic issue when Snapshot is applied simultaneously with with multiple DDL operations
• Fix the issue that the store size in metrics is inaccurate under heavy writing
• Fix the potential issue that TiFlash cannot perform GC for the delta data after running for a long time
• Fix the issue of wrong results when new collation is enabled
• Fix the potential panic issue that occurs during lock resolving
• Fix a bug that metrics display wrong value

TiFlash v4.0.15

Bug fixes

• Fix the potential issue of data inconsistency that occurs when TiFlash is deployed on multiple disks
• Fix a bug of incorrect results that occurs when queries contain filters like CONSTANT < | <= | > | >= COLUMN
• Fix the issue that the store size in metrics is inaccurate under heavy writing
• Fix a potential bug that TiFlash cannot restore data when deployed on multiple disks
• Fix the potential issue that TiFlash cannot garbage-collect the delta data after running for a long time