TiFlash v5.2.0

Improvements

• Add operators: MOD / %, LIKE
• Add string functions: ASCII(), COALESCE(), LENGTH(), POSITION(), TRIM()
• Add mathematical functions: CONV(), CRC32(), DEGREES(), EXP(), LN(), LOG(), LOG10(), LOG2(), POW(), RADIANS(), ROUND(decimal), SIN(), MOD()
• Add date functions: ADDDATE(string, real), DATE_ADD(string, real), DATE()
• Add other functions: INET_NTOA(), INET_ATON(), INET6_ATON, INET6_NTOA()
• Support Shuffled Hash Join calculation and Shuffled Hash Aggregation calculation in the MPP mode when a new collation is enabled
• Optimize basic code to improve MPP performance
• Support casting the STRING type to the DOUBLE type
• Optimize the non-joined data in right outer join using multiple threads
• Support automatically invalidating stale Regions in MPP queries

Bug Fixes

• Fix the issue that TiFlash keeps restarting because of the split failure
• Fix the potential issue that TiFlash cannot delete the delta data
• Fix a bug that TiFlash adds wrong padding for non-binary characters in the CAST function
• Fix the issue of incorrect results when handling aggregation queries with complex GROUP BY columns
• Fix the TiFlash panic issue that occurs under heavy write pressure
• Fix the panic that occurs when the right jon key is not nullable and the left join key is nullable
• Fix the potential issue that the read-index requests take a long time
• Fix the panic issue that occurs when the read load is heavy
• Fix the panic issue that might occur when the Date_Format function is called with the STRING type argument and NULL values

TiFlash v5.1.1

Feature enhancements

• Support the HAVING() function in DAG requests

Bug fixes

• Fix the potential panic issue that occurs when running table scan tasks
• Fix a bug that TiFlash raises the error about duplicated region when handling DAQ requests
• Fix the panic issue that occurs when the read load is heavy
• Fix the potential panic issue that occurs when executing the DateFormat function
• Fix the potential memory leak issue that occurs when executing MPP tasks
• Fix the issue of unexpected results when executing the aggregation functions COUNT or COUNT DISTINCT
• Fix a potential bug that TiFlash cannot restore data when deployed on multiple disks
• Fix the issue that TiDB Dashboard cannot display the disk information of TiFlash correctly
• Fix the potential panic issue that occurs when deconstructing SharedQueryBlockInputStream
• Fix the potential panic issue that occurs when deconstructing MPPTask
• Fix the potential issue of data inconsistency after synchronizing data via snapshot

TiFlash v4.0.14

Bug fixes

• Fix the potential panic issue that occurs when compiling DAG requests
• Fix the panic issue that occurs when the read load is heavy
• Fix the issue that TiFlash keeps restarting because of the split failure in column storage
• Fix a potential bug that TiFlash cannot delete the delta data
• Fix the incorrect results that occur when cloning the shared delta index concurrently
• Fix a bug that TiFlash fails to restart in the case of incomplete data
• Fix the issue that the old dm files cannot be removed automatically
• Fix the panic issue that occurs when executing the SUBSTRING function with specific arguments
• Fix the issue of incorrect results when casting the INTEGER type to the TIME type

TiFlash v5.0.3

Improvements

• Support casting the STRING type to the DOUBLE type
• Support the STR_TO_DATE function
• Optimize the non-joined data in right outer join using multiple threads
• Support the Cartesian join
• Support the LEFT() and RIGHT() functions
• Support automatically invalidating stale Regions in MPP queries
• Support the ABS() function

Bug Fixes

• Fix the issue that TiFlash keeps restarting because of the split failure
• Fix the potential issue that TiFlash cannot delete the delta data
• Fix a bug that TiFlash adds wrong padding for non-binary characters in the CAST function
• Fix the issue of incorrect results when handling aggregation queries with complex GROUP BY columns
• Fix the TiFlash panic issue that occurs under heavy write pressure
• Fix the panic that occurs when the right jon key is not nullalbe and the left join key is nullable
• Fix the potential issue that the read-index requests take a long time
• Fix the panic issue that occurs when the read load is heavy
• Fix the panic issue that might occur when the Date_Format function is called with the STRING type argument and NULL values

TiFlash v5.1.0

Improvements

• Support Union All, TopN, and Limit functions
• Support the Cartesian product including left outer join and semi anti join in MPP mode
• Optimize lock operations to avoid that running DDL statements and read operations are blocked by each other
• Optimize cleanup of expired data by TiFlash
• Support further filtering of query filters on timestamp columns at the TiFlash storage level
• Improve the startup and scalability speed of TiFlash when a large number of tables are in a cluster
• Improve TiFlash compatibility when running on unknown CPUs

Bug Fixes

• Fix the issue of incorrect results when casting the time type to the integer type
• Fix a bug that the receiver cannot find corresponding tasks within 10 seconds
• Fix the issue that there might be invalid iterators in cancelMPPQuery
• Fix a bug that the behavior of the bitwise operator is different from that of TiDB
• Fix the alert issue caused by overlapping ranges when using the prefix key
• Fix the issue of incorrect results when casting the string type to the integer type
• Fix the issue that consecutive and fast writes might make TiFlash out of memory
• Fix the potential issue that the exception of null pointer might be raised during the table GC
• Fix the TiFlash panic issue that occurs when writing data to dropped tables
• Fix the issue that TiFlash might panic during BR restore
• Fix the issue of incorrect results when cloning shared delta index concurrently
• Fix the potential panic that occurs when the Compaction Filter feature is enabled
• Fix the issue that TiFlash cannot resolve the lock fallen back from async commit
• Fix the issue of incorrect results returned when the casted result of the TIMEZONE type contains the TIMESTAMP type
• Fix the TiFlash panic issue that occurs during Segment Split

TiFlash v5.0.2

Improvements

• Optimize the table lock to prevent DDL jobs and data reads from blocking each other
• Support casting the INTEGER or REAL type to REAL type

Bug Fixes

• Fix the issue of incorrect results when cloning shared delta index concurrently
• Fix the potential issue that TiFlash fails to restart with incomplete data
• Fix the issue that old dm files are not removed automatically
• Fix the potential panic that occurs when the Compaction Filter feature is enabled
• Fix the potential issue that ExchangeSender sends duplicated data
• Fix the issue that TiFlash cannot resolve the lock fallen back from async commit
• Fix the issue of incorrect results returned when the casted result of the TIMEZONE type contains the TIMESTAMP type
• Fix the TiFlash panic issue that occurs during Segment Split
• Fix the issue that the execution information about the non-root MPP task is not accurate

Pre Release v5.2.0-alpha

use multi threads for not joined data (#2083)

Pre Release v5.1.0-alpha

Pre Release v5.1.0-alpha

TiFlash v4.0.13

Improvements

• Automatically clean archived data to free up disk space

Bug Fixes

• Fix the issue that number of delta-merge-tasks is not reported to Prometheus
• Fix the TiFlash panic issue that occurs during Segment Split
• Fix the issue that the Region write Duration (write blocks) panel in Grafana is shown in a wrong place
• Fix the potential issue that the storage engine fails to remove data
• Fix the issue of incorrect results when casting the TIME type to the INTEGER type
• Fix a bug that the behavior of the bitwise operator is different from that of TiDB
• Fix the issue of incorrect results when casting the STRING type to the INTEGER type
• Fix the issue that consecutive and fast writes might make TiFlash out of memory
• Fix the potential issue that the exception of null pointer might be raised during the table GC
• Fix the TiFlash panic issue that occurs when writing data to dropped tables
• Fix the TiFlash panic issue that occurs during BR restore
• Fix a bug that the weights of some characters are wrong when using the general CI collation
• Fix the potential issue that data will be lost in tombstoned tables
• Fix the issue of incorrect results when comparing the string which contains zero bytes
• Fix the issue that the logical function returns wrong results if the input column contains null constants
• Fix the issue that the logical function only accepts the numeric type
• Fix the issue of incorrect results that occurs when the timestamp value is 1970-01-01 and the timezone offset is negative
• Fix the issue that hash value of Decimal256 is not stable

TiFlash v5.0.1

New Features

• Add tools to check the status of tiflash replica for online rolling updates

Improvements

• Optimize the configuration file and remove useless items
• Reduce the size of TiFlash binary files
• Use an adaptive aggressive GC strategy to reduce memory usage

Bug Fixes

• Fix the issue of incorrect execution results when the default value of the binary type column contains leading or tailing zero bytes
• Fix a bug that TiFlash fails to synchronize schema if the name of the database contains special characters
• Fix the issue of incorrect results when handling the IN expression with decimal values
• Fix a bug that the metric for the opened file count shown in Grafana is high
• Fix a bug that TiFlash does not support the Timestamp literal
• Fix the potential not responding issue while handling the FROM_UNIXTIME expression
• Fix the issue of incorrect results when casting string as integer
• Fix a bug that the like function might return wrong results